When is Bulk Fermentation Done? - Episode 6 - "Starter Strength and Leaven Percentage"

This two-part, groundbreaking video demonstrates 1) how to strengthen a weak starter, and 2) demonstrates the impact of leaven percentages on bulk fermentation times.
A continuation of the fascinating experiment in Episode 5, this episode provides valuable new tools for estimating the impact of leaven percentages on bulk fermentation times.
"The first rule of sourdough baking is, "you don't make the bread, the starter makes the bread." Show your starter some respect.
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Sections in this video
0:00 Introduction
5:28 Part 1: How to Strengthen a Weak Starter
6:20 What does a strong starter look like?
7:50 How to strengthen a weak starter
8:30 6-Day Starter Strengthening Program (SSP)
9:50 Day 1 Starter Strengthening
11:50 Day 2 Starter Strengthening
13:20 Starter Feeding Ratios
13:55 The Camping Analogy
15:10 Starving Starter?
16:10 Day 2 Feeding
16:50 Day 3 Starter Strengthening
17:30 Changing Feeding Ratios
19:40 Day 4 Starter Strengthening
20:25 Day 5 Starter Strengthening
22:05 Day 5 pm Feeding
22:50 Day 6 Conclusions
27:45 Part 2: The Impact of Starter Strength and Leaven Percentages
29:45 The Leaven
32:10 2.5 Hours after Mixing
33:55 3.5 Hour Checkpoint
43:45 Loaf 1 (30%) BF Done
49:00 Loaf 2 (20%) BF Done
52:35 Loaf 3 (10%) BF Done
56:25 Loaf 4 (5%) BF Done
59:30 Summary of BF Times
59:50 Day 2 Score and Bake
1:02:07 Comparing the Loaves
1:06:00 Cutting the Loaves
1:10:20 Slicing the Loaves
1:13:25 Taste Test
1:15:50 Review of Findings
1:20:05 Summary

[@emrearslan1]

You deserve a PhD in Sourdough. Thank you for the great content.

[@thesourdoughjourney]

Wow, thank you! I appreciate the feedback.

[@HungryShots]

For the length of this video, I can watch a movie. I chose instead, your video. Always so detailed, so technical, so well documented. A lot of things to learn here. I knew that the strength of the stater is extremely important, now you just demonstrated to us. Congratulations once again!

[@thesourdoughjourney]

Thank you. And thanks for watching.

[@chimanchoi7069]

You are truly a sourdough professor! Thanks for the detailed explanation. Unlike other videos, thanks for explaining how and why things are done. Keep up the good work! My bake has much improved since watching your video! Cheers!

[@chimanchoi7069]

Perhaps a follow up video on the search of ideal balance between latic acid and wild yeast population in terms of percentage with the help of ph testing device to achieve the ultimate in terms of flavour and rise?

[@thesourdoughjourney]

Thank you!

[@thesourdoughjourney]

Yes, I actually bought a pH meter for this experiment but it didn’t work so I was unable to get consistent readings.

[@JoseLausuch]

This work you are doing is majestic. Your experiments and conclusions are very helpful for the sourdough community. Thanks a lot for doing this! Maybe you could increase visibility if you post your findings in IG as well. I think this should reach as many people as possible.

[@thesourdoughjourney]

Thank you for the feedback. I am looking into IG now.

[@barrychambers4047]

I concur!

[@valeriafuriasse9903]

agree. would be awesome to find you on ig

[@mikefisc9989]

This series should be must view material for new sourdough bakers. It is both informative and entertaining.

[@thesourdoughjourney]

Thank you!

[@corteltube]

Your videos teach how to take the varying elements, put them into context and teaches the art of observation 😊. A combination of learning and instinct.

[@thesourdoughjourney]

Thank you. I am learning myself as I do these experiments and trying to share my own learning experience in real time. I try to capture these “instincts” as they are discovered and before they become second nature. Experienced bakers seem to have a hard time describing what they are actually doing.

[@jimfromri]

Oh man, your board of directors are a demanding lot! Love your sense of humor. Another great video and I learned a lot. Off to strengthen my starter now. Thanks Tom.

[@thesourdoughjourney]

They are tough guys to work for.

[@jackskalski3699]

Amazing! It would be awesome to also have another variable in the bulk fermentation formula - the PH. Some people claim pH alone can sum up when bulk hits the sweet spot. Love your channel. It also tells me one more thing. It's awesome to have a strong yeasty starter and it might make sense to have a second acidic starter on the other end of the spectrum to be able to pick and choose or even mix them for different outcomes. The shaping less phenomenon is ground shattering. I do think that we should assume for now that it's true only for the yeasty end of the spectrum of starters. Not sure if shaping less is still true for the acidic. Love it

[@thesourdoughjourney]

Thank you! I started using pH testers about 3 months ago and have done over 100 tests now. I’ll be publishing videos on this topic in 2023. I know some bakers who keep two starters, as you describe. One high acidity and one low acidity. They both rise the dough equally well. Acidic starters do better at low fermentation temperatures. It is the combination of acidity and temperature that starts to cause problems. Thanks for the feedback. Some great content coming out soon. Stay tuned.

[@DRz754]

@@thesourdoughjourney LOVE your videos! Great explanations and experiments (and humor:). In this Episode 6, you experiment with the percent of levain. The visuals are so very helpful. What about taste? Does more levain = more sour taste? My goal is to bake sourdough bread that doesn't taste so sour and since I retired, time isn't a big issue (yet). I 'm a newbie & still haven't watched all your videos, but plan to. Thank you for all the effort!!!

[@happybackchiropractic]

Omg... Over the top Tom! ... You’re getting more creative, inventive... and hilarious! I recall looking at this title thinking... “Eh, prolly don’t need to watch this one...” I’m still only 10 minutes into it! I’m so shocked with the level of valuable content and entertainment that I was driven to send you a comment... read other fun comments from your other viewers... wow. “You need to show your starter a lil respect” ✊🏻 So good 😂 Thx again Tom 🙏🏼

[@thesourdoughjourney]

Thank you. The intro to Episode 6 was my high point so far...

[@rochellaostrowski1007]

Thank you!!!! You have taught me SO much! It’s the starter!!!!

[@thesourdoughjourney]

Thank you

[@user-qk8zn5bm6f]

Hi from Norway Tom! I just recently discovered your channel and you web page and WOW am I blown away🤩I have had my starter for a little over 2 years and although I haven't really used it an awful lot I have maintained it to a certain degree. However, in the jungle of information I haven't really been able to understand how to get consistency to my baking including what goes into getting a strong starter. Other than more love and attention I haven't figured out the details in what is actually happening when my starter seems more happy and active. Watching your videos I realize I'm guilty of all the common mistakes you list. Your loaves of "false hope" just hit me right in the heart😄 I will continue watching your videos (I also bought the Tartine bread book) and take this step by step and I have hopes that I will progress on my journey. Thanks for sharing all your knowledge in these fantastic videos❤

[@thesourdoughjourney]

Thank you for the feedback. I appreciate it. Also check out my new website at thesourdoughjourney.com

[@steveinmidtown]

something that may be useful is a "Starter O Matic" like the bulk fermentation version. It's basically the same but without the "windownpane" test & could be replaced with "consistency" or something demonstrating strength. Seems like the starter is essentially a "mini loaf" preview. I put the Bulk O Matic into an Excel format if anyone would be interested in a copy...makes keeping notes & comparisons efficient.

[@thesourdoughjourney]

Thanks. I am working on a generalized test of starter strength. Hope to have something out later this year.

[@bobwhiteneck5775]

One of the most interesting and informative videos! Great job as always!

[@thesourdoughjourney]

Thank you!

[@BobACNJ]

Thank you again for another great experiment and presentation.

[@thesourdoughjourney]

Thanks!

[@steveinmidtown]

OK...I've been fighting this sourdough odyssey for the last 2 years doing what seems like everyone else is doing with consistent favorable results being elusive. I've watched a majority of this series...this is the Ark of the Covenant for sourdough. There are few times in life I've had a revelation about something but the 1st 30 minutes was exactly that. All the other stuff as demonstrated, is a sideshow without a good engine. I started turning my sad little starter into an atomic bomb this morning & am stoked. Thank you very much for the tenacity & perseverance to get those, like myself flailing around, on target!

[@thesourdoughjourney]

Thank you for the feedback. This was such a huge breakthrough for me when I realized how much impact a stronger starter has on the whole process. It makes everything else easy. And there is a lot of nonsense out there now about using 5-month old, unfed starter to make sourdough. Sure it might work but it takes 3 days and lots of other things can go wrong along the way. A strong starter is the secret that no one tells you about when they bake consistently perfect loaves.

[@steveinmidtown]

@@thesourdoughjourney Sorry to post again but I baked a loaf using the "Bulk o Matic" yesterday. Just wow. I focused mainly on the time...I've been using the "full proof" method which has several coil folds & bulks almost 9 - 10 hours. Yesterday I cut it to 7 hours & only 1 coil thinking this is going to be a waste but, & this is why I'm posting, the loaf EXPLODED. I've never had a spring like this morning. Big curly ear, too. Not only that, the shape from all angles finally looks right. Looks like I've been overproofing & had no clue. Again, your meticulous research is absolutely amazing for those wanting to have killer sourdough. Haven't cut it yet to do the "brain/CTE" exam but can't wait. Finally, this is my 32nd loaf...not quite 100 but your insights made learning this incredibly complex endeavor much more efficient....that & scores lots of points with the wife!

[@thesourdoughjourney]

@@steveinmidtown thanks for the feedback. I appreciate it.

[@nicolalb695]

Hi Tom, this experiment is so helpful, especially how to strengthen a weak starter and what it looked like each day. Now I know what to look out for. Thanks!

[@thesourdoughjourney]

Thanks for the feedback.

[@alfontana6242]

Your video is well presented and you cover all the basis. Great Job!!!!!

[@thesourdoughjourney]

Thank you. I appreciate the feedback.

[@santanany]

Great video. I’ve learned so much. Thank you for your detailed videos and scientific approach to baking. Love it!

[@thesourdoughjourney]

Thank you for the feedback. I appreciate it.

[@jbond6576]

You are amazing Tom! This is a very helpful video.Your videos helped me SO much 🙂 Thank you.

[@thesourdoughjourney]

Thank you for the feedback. I appreciate it.

[@rybyakov]

Awesome work!

[@thesourdoughjourney]

Thank you.

[@leswetnam]

“You can’t force feed a weak starter.” Love it! Made me laugh. :)

[@thesourdoughjourney]

Thanks!

[@vinaymieux]

Love your videos. I loved the board meeting. They were definitely not happy. 🤣 Have learnt a LOT from you. Thanks.

[@thesourdoughjourney]

Thank you!

[@Kokeshiflower]

This was such an interesting watch, thanks for sharing your in depth research. I've just ordered myself a copy of Tartine Bread, and with your videos hoping to improve my loaves.

[@thesourdoughjourney]

Thank you. This was one of my most fascinating experiments.

[@dianel.9703]

Great experiment and video. Thank you. I also find the strength of the starter to be extremely important in my sourdough journey.

[@thesourdoughjourney]

Thank you for the feedback. Yes this is a key variable missing in so many discussions of recipes and troubleshooting.

[@fennyfen4819]

Hi Tom, all your video very detailed thank you!

[@thesourdoughjourney]

Thank you.

[@emmabaido458]

Wow! This really is amazing, you are amazing! Absolutely fascinating. Thank you, thank you, thank you! 🙏

[@thesourdoughjourney]

Thank you.

[@shirleywodzenski4791]

Amen! Amazing info. I wa gerri g discouraged, I’ll trudge on. Thanks Tom for all you’ve shown us.

[@thesourdoughjourney]

Thank you. Good luck!

[@miric6224]

Hi Tom, let us lnow when your book is available. Carefully worrded, assumed you’re writing, hope you R. Great video in many ways: informative, excellent speaking skills, clear transfer of info, humor, pleasant backdrop, unique presenation, OMGosh. Only need smellavision. Thank you and keep writing!

[@thesourdoughjourney]

Thank you for the feedback. I’m focusing on video content right now but will consider other options in the future.

[@DANVIIL]

You need to get a patent on the Bulkamatic System developed at the Institute. Maybe the Board of Directors would grant you a 5% commission on your invention.

[@thesourdoughjourney]

Thank you. It really works. I’ve done 8 episodes using it now and haven’t broken it yet.

[@j1303901]

You are amazing! Thank you

[@thesourdoughjourney]

Thanks for the feedback. This experiment was a real breakthrough.

[@jamesmoyer8386]

I’ve just watched episode 7, yes the answer to my last question was there. it’s interesting you can let the colder dough go further. For me at 80-82 I’m bulking in 3.5 hours, so I find I’m folding quite late in the process which I think is giving me a denser crumb. I’ve countered this by removing the stacking part of the pre shape and simply lightly rounding (although as time goes on I’m moving back closer to the original recipe; I had introduced a lot more mixing and coil folds but I think this this was introducing too much tension). Now I’ve found I’m getting better results bulking at 65-68. This typically takes me 6-7 hours. Part of me that suspects I’m not getting the full potential out of the yeast bulking at a sub prime temperature, but if i build a leaven warmer it can hit the ground running to counter this a bit. Do you have any recommendations for places to post crumb pics? I’d like to get some feedback.

[@thesourdoughjourney]

Thanks. Yes, the late handling and tight preshaping can produce a more dense crumb. If you are on Facebook, I’m in the groups Sourdough Bread Baking, Sourdough Bakers and Sourdough Geeks. This is where people post crumb photos and I comment.

[@pattyinsandy]

You are the best❤ thank you.

[@thesourdoughjourney]

Thanks.

[@debbiemoore6358]

Bless your heart Tom! I’m just now seeing your response. I found my answers from watching your other videos. Thank you so much for your responses. A other question.....I understand bulk fermentation. The yeast needs to fill the gluten holes with carbon dioxide. Lets say the recipe calls for a 4 hr bulk fermentation. Time/temp done. Next comes shaping and the banneton for the next stage; proofing. Why use the word proofing? You mentioned the yeast/lactic bacteria don’t know it’s time to stop fermenting just cause it hits the fridge. So besides shaping, resting then plopping into the banneton, what is proofing? Isn’t it just ongoing fermentation? I guess I’m just stumped by the word proofing? I hope you’re getting well paid for these videos AND answering questions😎

[@thesourdoughjourney]

Thank you so much. “Proofing” generally refers to the overall outcome of all of the fermentation steps. The primary steps are bulk fermentation and final proofing. One of the steps, “final proofing” has “proofing” in its name, but the ultimate proofing of a loaf is a collection of all of the fermentation related steps. Kind of like if you were painting a wall in your house, the steps in painting actually include cut in, rolling and touch up, which are three subtypes of “painting,” but at the end you would simply say the wall is nicely “painted.” At the end of this video kzbin.info/www/bejne/aqqwXpqBoayLa7s , around 53:20, I describe all of the steps.

[@queeniebeats3028]

Thank you, its like trying to understand Calculus, but better.

[@thesourdoughjourney]

Haha. Yes. Exactly.

[@TheDuckofDoom.]

Part of the reason 12 hour feedings help is that yeast is aerobic when reproducing and anaerobic when fermenting. On the other hand lactobaceria are just anaerobic. So fresh mixes bring more oxygen and allow the yeast to mutiply much faster than the bacteria. The favorable environment also allows faster growing yeast strains to outpace the weaker strains, at the micro level it isn't really strengthening any of the strains. Basically you could just add a heavy pinch of commercially grown yeast and have a similar macro effect in about 2 feedings. It's just favoring a faster growing strain and you would still have some percentage of wild critters for flavor. (GASP, commercial yeast near sourdough is heresy!)

[@thesourdoughjourney]

Thanks.

[@qwerty11111122]

1:14:30 That agrees with an experiment I did once. I did the math wrong and ended up using only 2.5% mature leaven with my old starter. It fermented for 2 days and ended up with what my friends called "Spicy bread".

[@thesourdoughjourney]

Thanks for the feedback.

[@thesourdoughjourney]

That is known as the “Respectus Panis” method. baking-history.com/respectus-panis/

[@barrychambers4047]

Another great video Tom! Thanks! Just so you know, my bulk fermentation is pretty much on par with your times. I've never ended bulk anywhere close to Tartine Bread's suggested times. May I ask, where did you dig up all of this cool information on the starter, or did you figure it out for yourself? It really makes sense the way you laid it out.

[@thesourdoughjourney]

Thanks Barry. I figured it all out in my own. I found a few scientific papers on yeast growth and acidity, but nothing really clear cut for sourdough starters.

[@summerjohnson382]

What do you use for a banneton basket for the mini loaves in these videos?

[@thesourdoughjourney]

A small loaf pan with a wooden insert I made to reduce the size down. You can use small loaf pans lined with a towel.

[@copybaste2637]

Amazing content! Thank you 🙏 your dedication and passion is admirable! What camera are you using to take these long time-lapses? I’d like to replicate your experiment so I can strengthen my weak starter as well. My camera has a 30 minute recording limit… 🤦‍♂️

[@thesourdoughjourney]

Thank you. I record these in an older iPhone (6 or 7?). It does not have a limit on time lapse.

[@lindsaysketokitchen9077]

Hello! Still loving your videos and learning so much! Thank you.... quick question - and maybe I missed this in a different video (sorry!) - why do you not preshape and shape your dough? I'm just curious if this is because of your experiment or if that's something you don't do regularly? THANKS!

[@thesourdoughjourney]

I only skip the shaping steps in this series so I can isolate the impact of bulk fermentation. Preshaping and final shaping can introduce a lot of irregularities into the crumb that can be misread as fermentation issues (e.g., gas bubble introduced in shaping, or dense crumb areas caused by tight shaping).

[@lindsaysketokitchen9077]

@@thesourdoughjourney much appreciated! Thank you

[@ginabostrom6126]

Love your videos. I am a newbie and I am on day 10 of my sourdough starter. I was on 1:5:5 (70g rye, 30g bread flour, 100 grams water and changed to 1:2:2 (80g bread four, 20 g rye) tonight with 2 feedings per day. It doubles the size on the 12th hour but no more than that. Should I change ratio to 1:3:3 to get it really strong or should I wait some more before switching ratios? Thanks a lot.

[@thesourdoughjourney]

Thanks. I’d continue at 1:2:2.

[@judithmingram6144]

Ahhhhh! Another gem! I'm going to do this! Question: Why not go straight to feeding every 12 hours? Thanks!

[@thesourdoughjourney]

Great question. You can dilute and weaken your starter by over feeding it or feeding it before it fully peaks. If I had just gone by the clock and done a 12 hour feeding on day 1, I would have weakened and already weak starter. The maximum yeast population occurs some time after it peaks and I find the maximum strength to actually be during the decline after the peak.

[@jamesmoyer8386]

Hi Tom, For all the insight the incredible bulk-o-matic system provides, did you not just call each at 30%? Also have you tried bigger loaves without any shaping? If so did you achieve similar results or did gravity start to have a greater impact?

[@thesourdoughjourney]

Great question. Watch Episode 7 for the answer. It is temperature dependent. Lower temperature dough needs a higher percentage rise. I have done 500g flour-weight loaves with the same results of no shaping. I don't recommend no shaping because there are benefits, but once you see what you can get with little or no shaping, it focuses your skills on all the prior steps of building dough strength before the shaping steps. It is a good challenge from time to time, and a good mental exercise when you are making any loaf to ask yourself the question "what if I didn't do any shaping on this loaf?" Are you getting the most out of the prior steps?

[@Leekeumkyu]

Hi. Thank you for your great job. And I have question about hydration rate. (32:40 of this video) How can you measure hydration rate for leaven? It doesn't look like 100% hydration leaven. Can you tell me more detail for this?

[@thesourdoughjourney]

Thank you. That is 100% hydration leaven. That means I used equal parts flour and water by weight. For this recipe I take 10g of prior starter and add 100g of water and 100g of flour. The flour is a 50/50 blend of bread flour and whole wheat flour.

[@Leekeumkyu]

@@thesourdoughjourney Thanks for answer. But still I confuse. From table of video, Loaf #2. Flour is 250g, water 188g, Leaven 50g(= water 25g). And Hydration rate is 77.5%. But I thought hydration rate is ((188+25)/250) *100 = 85.2%. What did I missing? Can you tell?

[@thesourdoughjourney]

Good question. It can be confusing. When calculating the total hydration of the recipe you need to add the water content from the starter to the numerator and the flour content of the starter to the denominator: 188g water plus 25g water from starter = 213 total water 250g dry flour plus 25g flour from starter = 275 total flour 213 water / 275 flour = 77.5% hydration

[@Leekeumkyu]

@@thesourdoughjourney Right! I forgot flour from leaven. Thank you a lot. Now I got my answer. ^^

[@klaskristian1]

Haha. Funny and good video as usall!

[@thesourdoughjourney]

Thank you. Glad you enjoyed it.

[@klaskristian1]

@@thesourdoughjourney Yes, i did

[@margielaughlin6056]

Hi! Can you tie this to the current recommendation of feeding 1:1:1 for maintenance?

[@thesourdoughjourney]

1:1:1 is where I always starts with basic “sustenance” feeding. If you need to occasionally strengthen your starter (think if it as routine maintenance), this is a method. This method is using a fixed timing of feeding, then adjusting the feeding ratio as the starter strengthens. Another option is to stick with 1:1:1 and wait for the starter to peak, then as soon as it peaks, discard 2/3rds and refeed (that is the “peak to peak”) method.

[@margielaughlin6056]

@@thesourdoughjourney after I have strengthened my starter, if I want to maintain q 24hrs, how do I find the right ratio without diluting the seed? Sorry, I thought you were saying not to discard more than 2/3, but 1:1:1 doesn’t quite go 24 hrs.

[@thesourdoughjourney]

The best way slow it down is to reduce the temperature. But if you cannot, then increase the feeding ration. If 1:1:1 doesn’t make it 24 hours, then discard 80% and go up to 1:2:2. If that doesn’t make it 24 hours then go up to 1:3:3, etc.

[@crystalsypniewski857]

Should the percentage of rise be the same for a 30% loaf and a 5% loaf? In another video, you explain that the percentage of rise is directly related to the fermentation temperature. Would it be the same with the percentage of levain? I'm wondering if there would be any benefit in cutting bulk fermentation off slightly earlier with a 30% and slightly later with a 5%? What are your thoughts on that? Also, I've been feeding my starter 1:2:2 every 24 hours for a few days now. It peaks in a reasonable amount of time but then holds peak for 8+ hours. It starts falling but only ever gets about halfway to the starting point within the 24 - 26 hour range. Should I continue with the same feeding schedule or is it just because it's cooler here in Cleveland right now? It just seems to be maintaining, not getting stronger.

[@thesourdoughjourney]

The % of starter only impacts the time, not the target percentage rise. Your starters time to peak is more important than the falling. As long as it is “past peak” it is ok to feed. Some starters don’t fall flat for a long time. That is OK.

[@akulinaakulina6742]

Thank you, Tom, for your explanations. But I’ve got a question. If I want to bake a tin bread (in the form, pan) or pizza what dough rise is recommended ? Because in this case fermentation and proofing are united. Before to go into the oven must my dough be risen for 100% or less ?

[@thesourdoughjourney]

That is a really difficult question to answer. The rise in the dough is really specific to the recipe. For example the Tartine recipe which I follow recommends a 20-30% rise but that is based on the specific steps of that recipe. I recommend finding a recipe specifically for what you are trying to make (e.g., there are many recipes for sourdough pizza dough which are slightly different than bread recipes) and follow the guidance in this recipes. The targeted percent rise is a function of many factors and there is no general guidance that applies across all recipes or baking environments.

[@akulinaakulina6742]

@@thesourdoughjourney Unfortunately in most of the recipes they say to wait “until double in size” or to proof for some certain time but I have other room temperature. You say that for fermentation is good 30-40% rise, in the other place I found that for proofing is good 30-40% as well. So 60-80% rise (fermentation + proofing) and the dough is ready to go into the oven ? The rest 40-20% the dough should rise in the oven when baking ? Or better to make the dough rise up to 100 % in volume before baking ? Not much information on this subject 🤔🤔

[@jaimegallo4745]

Do You have recomendaciones Ford gluten free doughs?

[@thesourdoughjourney]

Sorry, that’s not my speciality.

[@susanparker9803]

Tom, I built an overnight 10g:55g:55g leaven. It peaked at around doubling stage (maybe 110%) - really nice and frothy. Is that a good enough leaven or do I really need one that peaks at triple (as shown in Kristen's video that you link to). My bulk ferment rise with this leaven today is not quite at 30% after 6 hrs - I decided to shape it as my issue lately has been overproofing. But is this a sign of weak leaven/seed starter?

[@thesourdoughjourney]

Leaven sounds fine. It does not need to double or triple, just “peak.” Some are taller than others and it doesn’t necessarily mean stronger. Just different. 30% at 6 hours is only typical if you’re keeping your dough temp near 80F.

[@susanparker9803]

@@thesourdoughjourney Thank you! I kept my dough consistently 79-80F throughout. Based on bulk-o-matic, I thought I'd see 30% by 4.5 hr mark (realizing of course that nothing is exact with timing and sourdough...)

[@noniof5711]

Trying to comprehend the "strength factor". At 24:35 would I calculate the 22.73ml rise divided by 5.5 doubling time and then divide that by ?? What is the amount of original starting grams of starter...the original amount at the beginning of the 6 days or the amount used for the day 6 1:3:3 feeding? This is all so interesting!!

[@thesourdoughjourney]

it is divided by the grams of starter in that day’s feeding.

[@noniof5711]

Thank you!

[@noniof5711]

@@thesourdoughjourney Sorry, I need further help! I am trying to build the 'strength factor' of my starter. I started doing the method you've outlined here. I had to leave for 5 days so put my starter in the fridge. Now, last evening I got the starter out and fed 1:2:2 - 25g starter 50g water/flour. This morning 12 hours later it has doubled. So to figure the calculation I take the 100ml it rose and divide by 12 hours giving me 8.33ml per hour of rise. Then divide that by 25 (grams of starter used) to get a strength of .33? What am I doing wrong?

[@jamesmoyer8386]

Have you attempted to apply the bulk-o-matic without using the %rise metric, going ‘Jedi’ so to speak? Another interesting thing for me Is you didn’t see any deterioration in crumb with in increase in prefermented dough. I’ve read previously that an increase in starter percentage leads to a tighter crumb and less soft texture.

[@thesourdoughjourney]

Yes, in a few cases where I use an unmeasured bowl. In those cases, I rely on 1) temperature and time if it's my typical recipe, 2) smell, 3) wobble. Then all of the other variables to a lesser extent. And obviously, eyeballing the % rise, but not measuring it. If you watch the pros, eyeball all the visual variables, then do smell, wobble, and a little touch which is essentially a micro-windowpane. And usually are aware of time and temp. Essentially, everyone is doing all the variables to some extent, just some more instinctually. Maybe sometime I'll do a "blind" test where I need to only go by smell. Or a touch test, where I can't see the dough. That would be interesting.

[@flowerbomb333]

Professor. I’m reporting you to the Sourdough Starter Protection Services ! No only are you a musician and Sourdough Professor at the Institute, you are also a Comedian ...who knew 😂. Great video ! Thank you

[@thesourdoughjourney]

Thank you. It takes a little humor to get through a 1 hour and 20 minute sourdough instructional video. :)

[@alexandralyon9608]

HI Tom, I have been trying everything to regain strength in my starter for the past week with no success. I did some wacky things the first few days then found your videos and settled on a 1:1:1 feeding every 24 hours until I see results. So far, I get bubbles but no "doubling' not even any rising. Just bubbles. The smell is there and the bubbles make me think something is happening, even the consistency seems OK, but there's just no lift off... Any ideas how to bring it back?

[@thesourdoughjourney]

What kind of flour are you using ?

[@alexandralyon9608]

@@thesourdoughjourney Unbleached AP to start then I started adding Rye since that seemed to be a solution, still having no rise...

[@thesourdoughjourney]

The only thing to do is give it more time and keep it warm. Sometimes I put a splash of extra water in and stir it up. This will sometimes help wake it up.

[@birdwatcher1015]

This is fascinating. I do have a question-The starter gets its food energy from the flour-not the water. The water is just the carrier. So technically, why do you have to have an equal amount of water to flour? Couldn't you add a little more, or a little less water, and have the same results? ie your starter would just be more or less stiff than if it were a 1:1 ratio. My gut instinct is that when mixing the 1:1 ratio, it is more difficult to work with than if I added just a little more water-not to the point of soupy, but rather still thick but a touch more pourable. It may screw up your hydration calculations, but that is another issue my brain doesn't want a with right now (or possibly ever) (Asking for a friend)

[@thesourdoughjourney]

Yes, but the water is also the medium to help evenly distribute the nutrients to the microbes. The microbes live in clusters and they can’t swim. The water brings the food to them. But you can also make a stiff starter with similar results.

[@davidryangrossman]

Tom, Great content as always. Question for you. It seems like you're still having trouble translating your starter gains into levain gains. Have you tried refreshing your levain in the morning before mixing as Chef Robertson describes on page 47 or Tartine Bread?

[@thesourdoughjourney]

Good question. I feel like the starter gains transferred to leaven strength in this experiment. The leaven was frothy and strong here. I would only refresh the leaven if it were past peak in the a.m. then you can feed and refresh. If you see from this video (and not shown in the episode 5 leaven) it is not past is peak in the a.m. I’m pretty certain it is the source starter that I was not feeding regularly and was pretty lifeless. From my reading of page 47, or the leaven is not ready in the a.m. you put it in a warm place and give it more time. If it is past peak, you refeed it. I don’t show the source starter in either video (because a assumed each was fine at the time of feeding the leaven) but the starter in Episode 5 was spent, unfed and pretty lifeless when I fed the leaven. A lesson learned for me.

[@davidryangrossman]

@@thesourdoughjourney I think you should try it. It certainly appears in the book to be nothing more than a troubleshooting step if the levain is too far gone or particularly sluggish. I don't think that's the case though. Instead, I think it's an insight into how to get a young, powerful levain that mimics the kind Chef Robertson uses at his bakery. I too struggled with a weak starter and therefore weak levains for quite some time. I used some different methods to strengthen it - the inclusion of freshly milled flour, warmer round-the-clock proofing temperatures, and two-a-day feedings. In the end, my starter was strong and vigorous and peaked/tripled or quadrupled in about 7-8 hours on a 1:10:10 feeding ratio kept at 74 degrees Farenheit (that's 23.33333, repeating of course, degrees Celsius). You can imagine my excitement. I'd build my levain and ferment it overnight as usual, use it, like you, at or just beyond peak - that is, when the top began to weaken a bit and start to collapse in on itself without falling, only to find that, like you, the bulk time wasn't significantly shortened, nor was the levain's power or lift noticeably greater. I was stumped. Then I went back to the Tartine Bread book and noticed that part on page 47 about refreshment. It helped a ton. I found that my fermentation times decreased dramatically, to the extent that I have sometimes worried carrying the dough even 3.5 hours for fear of not being able to get the dough cold before it overproofs. Furthermore, the feel of the dough is markedly different and, in my opinion, better. It is less sticky and more supple than dough fermented with a 12-hour-old levain. This makes sense too because now only approximately 4.5% of the totall flour has fermented for 12 hours at mixing time. You replied to a previous comment that you find your levain is "strongest" at or just past peak, when mixed at a 1:10:10 ratio and fermented overnight at room temperature. I too found this to be the case. However, I found that strength to be a bit of an illusion. While the levain may be at its strongest, the question is, is it strong enough? No doubt the yeast colony is at its max, but so too is the bacteria colony from the long ferment. So both groups are going at the dough with equal vigor when you mix. All that bacteria tightens the dough and lends it elasticity, which in turn allows the dough to capture gas and move into the optimal range on many rows of your Bulk-O-Matic system. But that doesn't seem to allow for maximum rise or yeast-driven fermentation over a given amount of time. Furthermore, the longer the dough ferments, especially at home fridge temperatures, the more pronounced the bacteria's effect becomes. A late refreshment and warm fermentation of the levain seems to drop down the bacteria colony and give the yeast a head start. Here is how I do it if I am making a full batch of dough using the Tartine method. Night before: Mix 3-4 grams starter 50 grams 50/50 flour mix 50 grams water, room temperature DDT: 70-74 degrees Farenheit Ferment at 70-74 degrees Farenheit for 10-12 hours until at or just past peak. Basically just standard procedure up to this point but with half the normal amounts. Day of: Mix 105 grams levain, at or just past peak 50 grams 50/50 flour mix 50 grams water, 80-85 degrees depending on levain temp DDT:80 degrees Farenheit Ferment at 80-82 degrees for 90-150 minutes until doubled or tripled but well before "peak." It's going to rise precipitously. This type of levain looks markedly different than the 12 hour kind. It is gassy and vigorous but generally lacks the larger bubbles you see in a longer-fermented levain. You clearly have a wicked strong starter after giving it so much TLC. But it doesn't seem like all that strength carries over into your levain. You only shaved 30 minutes off your normal fermentation time. This might just do the trick for you in translating those starter gains into levain gains. The method I outlined above is a little bit fussier than the set-it-and-forget-it, 12 hour method, but the payoff is worth it if your baking schedule can absorb the two hour wait in the morning while the refreshed levain ferments. But that sure beats setting an alarm for 2 am to dump and shape dough, even if it's for the sake of sourdough science and honor. Plus, there's still no waste or discard of any levain, so it is materials neutral. I had the same take on refreshment as you - my levain is at its peak, why would I refresh it now? Well the answer, I discovered, is because Chef Roberton's recipe calls for a levain that is much younger than that. I believe that is because he wants to take advantage of a recently refreshed levain with a larger colony of yeast than bacteria to quickly leaven the dough during a warm bulk and then protect the dough from breakdown during the relatively long cold retard. Give it a shot and see what it does to your fermentation times. It might be interesting to see an experiment comparing levains at different stages of development - one before peak, one at peak, one past peak, and one that's been refreshed according to the process on page 47. I routinely refresh my levain now, and it has made a big difference both in the time and "power" of my fermentation and the overall quality of the dough when I make this recipe. I'd love to know how it works for you. I hope this helps.

[@thesourdoughjourney]

Thanks for the info. I will give it a try on my next loaf. The one thing I have always been curious about is how C. Robertson says the leaven should only increase by 20% overnight. That implies his leaven is not as far along as what I’m typically using. Which is consistent with your method also. The only way to achieve this is with much cooler overnight temperatures (55F/11C)? In C. Robertson’s recent audio book, his “Master loaf” recipe no longer does the overnight leaven. It calls for continuous short interval feeding of the starter (multiple times per day, I’m guessing every time it peaks).

[@davidryangrossman]

​@@thesourdoughjourney I have been curious about it too because it strikes me as confusing and blatantly wrong. It is one of several confusing or contradictory passages in the master recipe. For example, he recommends that you preheat your oven to 500F...for 20 minutes...and then throw your loaf in there. I'm not sure what kind of home oven he's rocking up there in the foggy bay, but mine down here on earth takes 25 minutes just to THINK that it's at 500F, though an oven thermometer on the shallow side of the combo cooker will only read 375F or so at that point. Here's another. Also on page 47, he says, "...bread bakers use weight measurements...For ease of calculation, the bread recipes throughout the book use metric weights. [New paragraph] The night before you plan to mix the dough, discard all but 1 tablespoon of the mature starter." He spends an entire paragraph talking about how metric weight measurements are basically essential and non-negotiable, and then uses an imperial, volumetric measurement in the very next sentence. Many of my early failures were because I hewed too closely to his overnight levain prep method. I would stick my poor little levain in an insulated lunch bag with one of those bright blue freezer blocks wrapped in a dish towel, dutifully let it "rise" overnight and then mix up a future frisbee with it. I didn't bake a real loaf of bread until I simply ignored that instruction and used a peaking levain. I don't think he is trying to be esoteric on purpose. Instead, I think he is trying to account for local conditions and the idiosyncrasies of our home setups by focusing on principles, to the extent possible, rather than specific times and percentages. So what is the principle here? I think it is to create a strong levain that has a small bacteria colony/low acidity level. That will keep the dough more extensible (which should help it hit its rise goal earlier in bulk because the gluten is not resisting the pressure of the gases that are filling it up) and stronger through an overnight cold retard. His initial solution for the home baker was the overnight method that gives literally everyone fits. I am not surprised he took it out of the audiobook. He revised the method in Tartine No. 3 to mixing the same ratios but using 80-85F water, proofing it at "moderate room temp," and using it after 4-6 hours. It seems like he'd already realized the first book had issues. In addition to all that, if you mix at, say, 8am, your dough will be ready to go into the fridge some time in the early afternoon. That means that if you adhere to the times in the recipe and let it retard for up to 12 hours, you'd be baking in the middle of the night. I know from previous videos this might be your kind of thing, but those of us who aren't as committed to sacrificing our bodies for sourdough science need a better way. The Tartine No. 3 method with a same day levain build gets the dough into the fridge in the early evening and into the oven first thing the next morning. I think you will see that if you try the refreshment method, the levain will grow considerably in 1.5-2.5 hours if mixed with 80-85F water and kept at 80-82F. It will definitely rise much more than 20%. But it is a very different beast. It feels, smells, and behaves differently than a 12 hour old, peaking levain, though it is clearly just as strong if not stronger. Because the bacterial and acidic levels are lower, you won't see that weakening and falling or collapsing of the top like you do in a more mature levain. As I understand it, the falling is due to the bacteria weakening the gluten chains. That won't happen in a refreshed levain. So with this method, rather than thinking of "peaking" as a maximal term that describes a levain with the highest yeast and bacterial counts, we need to think of it as a minimalist term that describes a levain with sufficient, high, but likely short of maximum, yeast and bacteria counts. Whereas before I would see the top stop doming and begin to flatten and know that it had peaked, now I simply look for at least a doubling (but usually closer to a tripling) of the levain in 1.5-2.5 hours and I am confident it will work very well. As a bonus, because it is newly refreshed, it has a larger use window than a peaking or past peak levain that has fermented overnight. That's a great cushion in case something comes up before you mix. On a side note, I thought I understood what "sweet" and "milky" and "fruity" meant until I used this method. Turns out I was just talking myself into smelling those notes in 10-12 hour old levain. A refreshed levain brings all of them to the fore. That translates to the finished bread too. You are awesome at the science part of all this, so I look forward to your findings if you ever dig into this aspect of the bake. I approach this like a knuckledragger and just try to fail up as much as possible, keep notes, and think through the "why" of it until I get a headache. I think you are right about the starter maintenance plan his people use at the bakeries. He mentions something similar in one of the videos I linked in a previous comment over the summer. That's out of reach for us, but I think the method I outlined above is in the ballpark. And hey, there is textual support for it. I am just giving it more emphasis and treating it less like a troubleshooting step and more as the preferred way of building the levain. I really only depart totally from the book in a few meaningful ways. I pre-heat my measly little oven for at least an hour, and I use warmer water to mix the dough. 80F water is simply too cool. I aim for the higher end of the desired range - 82-85F - at the beginning of bulk. That means I usually warm my water to 85-90F depending on the ambient temperature in my kitchen. That has helped me a ton. It speeds things up dramatically without having any deleterious effects on the dough or the finished bread.

[@thesourdoughjourney]

@@davidryangrossman Thanks for the feedback. That "tablespoon" measurement drives me completely crazy. It could vary by 2X in weight and have a material impact on the outcome of an overnight leaven build. In this video where I did the starter strengthening for days before baking, I know exactly what you mean by "fruity," "milky," etc. Those notes opened up totally differently in the leaven and the bread with this method. The only downside of the "young" leaven is the flavor was notably milder and less sour. You are probably compensating for this somewhat with your 85F bulk fermentation which will favor some of the acidic development. The leaven refreshment is definitely a key to getting this right. Thanks for sharing your insights.

[@shelly2758]

Forgive me if this was asked before…. What if your levan doesn’t float?

[@thesourdoughjourney]

The float test is a weak test of starter readiness. I call it a weak test because it is inconclusive. If your starter floats, it generally confirms that your starter is ready for baking, but if it does not float, it does not mean it's not ready. Some starters don't float because of the type of flour used (e.g., rye), and if you stir your starter before the float test, it will not float. And sometimes you can have a perfectly strong starter that just won't float. I still do the float test because it is generally reliable with my starter and my process. But it is not a universally definitive test.

[@josegomezgil1924]

Welcome to The Wild Yeast Training Bootcamp by the IIASSR! Get that lazy Starter going... ;-)

[@thesourdoughjourney]

Exactly.

[@troyheald77]

AAA+++Bedford, Texas

[@thesourdoughjourney]

Thank you.

[@PeKlim]

Maybe you get 3.5 hour bulk fermantation, when you use 40% innoculation. This is 20% innoculation calculated by flours ratio. Are you sure, that Tartin uses weight of whole starter with water and not weight of starter flour?

[@thesourdoughjourney]

Yes it is the total starter weight divided by the dry flour weight. 200g of starter divided by 1,000g dry flour.

[@chimanchoi7069]

I've changed from 100% rye starter to 25% rye and 75% strong white just to see if my starter can show visible sign of doubling. I'm sure my starter is strong and active because when I built a levain with wholemeal and strong white flour, it quite easily double and a half in six hours but I still think it's not strong enough as there are uneven distribution of air bubbles and there are a few large bubbles, very few medium ones and lots of small ones, resulting in a tight crumb and not the opened crumb structure I'm trying to achieve.

[@thesourdoughjourney]

Open crumb is a function of many things. Strong flour, high hydration, correct bulk fermentation and appropriate handling. Is focus on changing one variable at a time and you’ll be able to figure it out.

[@chimanchoi7069]

I had a break through today. I followed your steps and my starter triple in 6 hours at 25°c. And my gluten structure has strengthened enormously due to the strengthened starter! I still don't fully understand the whole strengthening starter process. I think it has a lot to do with gaining better understanding of your own starter and attend to it's needs. Some.recipes I came across suggest an extra feeding 6 hours before building the levain but it never explained why. I guess it's like you said in the video the idea is to boost the yeast population. It's all good if you've already have a strong and super active starter. If not, like your camping analogy; you're simply overfeeding a weak starter and weakening even more! One thing I am curious is that some people will increase the feeding to 4 times a day but wouldn't that cause the lactic acid to drop so much that the result bake will come out lack in flavour?

[@quantumchem3774]

I dont know that there is any long term value to having faster yeast. You want the slow ones that can withstand high acid and alcohol content too. The ones that can work at the extreme end tend to be slower to reproduce.

[@thesourdoughjourney]

I agree in general. It’s not about cultivating a “fast rising” yeast, it’s a “larger yeast population relative to the LAB population.” The LAB will always outrun the yeast, given enough time, and the acidity eventually chokes off the yeast production as the pH drops. So I want a larger yeast population at the starting line of the race. I know some other bakers who’ve manipulated the microbial mix through pH and temperature control. What I’m doing here is a much simpler concept of try to get a large yeast population - targeting mostly home bakers who tend to carry very acidic starters due to infrequent use or poor feeding regimens.

[@debbiemoore6358]

I have been watching your videos and love the science. I just watched the mystery of bulk fermentation. The key for me is the part that is missing. Towards the end you put the four small loaves in the fridge for cold retard. Then the next segment the loaves are baked. What happened in between? When you pulled out the cold loaves the next morning how long did they sit on the counter? Did you take their temp? When did you score, and did you use steam in the oven and mist the tops.

[@thesourdoughjourney]

I show that step in many of the other videos. I think I describe the steps in this video also in the "score and bake" section. Here is what I do. Take loaves out of fridge 14 hours after each loaf went into the fridge. The fridge temp is 37F. The loaves take about 10 hours to get down to that temp (in some other videos I show a chart of the continuous change in dough temp in the fridge over 12 hours). I dump the loaves onto parchment paper. No shaping, no bringing up to room temp. I score them and put them into 500F preheated dutch oven with lid on. Reduce temp to 450F and bake for 20 minutes. Then I removed the lid and bake for 15 more minutes at 450F. Remove and cool for 90 minutes before cutting.

[@thesourdoughjourney]

I demonstrate the steps at the beginning of this video. I always follow the same steps as shown here. kzbin.info/www/bejne/boW0iGmhr5yVfsk

[@blakelocati]

Omg so odd that you mention that your starters flour “came” from Petaluma,Ca. That’s where I live! So cool

[@thesourdoughjourney]

My brother lives in Burbank.

[@blakelocati]

@@thesourdoughjourney awesome! Thank for for the videos! They have been a massive help with my sourdough, especially with the bulk fermentation part as most recipes just don’t make the relationships between time, temp, and % rise very clear. If I may make a video suggestion, I think it would be really cool to do a “cobweb crumb” series where you try different techniques to get that sought after instagram hype crumb (like breadstalker). Thanks again!

[@thesourdoughjourney]

Thanks. I will add that to my list. If you buy breadstalkers ebook you’ll see that she adds sugar and egg to her starter. It is almost impossible to replicate her crumb without those add-ins.

[@blakelocati]

@@thesourdoughjourney I did buy it! I’m excited to try some of the tricks. My only complaint is that her book is more about the feel of the dough than the science of it. For example, she doesn’t really give an indication of how much she allows the dough to bulk before she shapes just that it should be fluffy and full of life. Super helpful book but I’d love to see the topic tackled by someone more science minded. 👍

[@blakelocati]

@@thesourdoughjourney it almost looks like she goes for 75% rise to a full doubling of the dough which is mind bending to me but I’m excited to give it a try.