Measure Green Coffee Bean Density

When we measure green coffee bean density, it can provide important information about the coffee we are about to roast. It forms our roasting plan including charge temperature and how the coffee will react when we apply heat over time. Knowing a coffee bean’s density prepares us to manage heat to optimize for flavor. It also gives us clues how the green coffee beans will behave during the dry phase, browning phase, first crack and even the development phase.
One of the things I love about my channel is being able to share what I have learned (and continue to learn) about roasting coffee. Low density coffee conducts heat slower through to the bean center than than a high density coffee. One of my "virtual " mentors is Joe Morocco who, along with Mill City, have shared a great amount of knowledge as it relates to coffee roasting theory. This topic of heat transfer being affected by density is important. I would encourage everyone to take a look at Joe's very good blog article as it relates to bean density, moisture levels and heat transfer here joemarrocco.com/2016/10/24/co...
According to Joe, he recommends a higher charge temp with very low gas at charge, and then ramping gas back up to a lower setting.
Thank you to @daRock1212 for the advice related to this topic. It is situations like this why I am so thankful for the home coffee roasting community!
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HOW TO MEASURE COFFEE BEAN DENSITY
We measure green coffee bean density by using a container like a drinking cup, fill it with 250 grams of water and mark the fill line with a dark marker. This is now the standard measurement for every coffee you want to learn it's density. Place the empty measuring cup you just made onto a scale, tare it, and then pour the green coffee beans into the cup, even to the fill line. The weight that displays on the scale is the green coffee's weight in grams. Now divide that by your standard of measurement which in this example is 250 grams. The result is a number that begins with a decimal Even a home coffee roaster can determine how to measure, something like 0.7692. Now simply remove the decimal and use the first 3 numbers, in this case, 769. This is our number! To know what this number is, refer to the ranges below:
High Density 700+
Medium Density 600 - 700
Low Density 500 - 600
Here is the formula for to determine the density of green coffee beans:
Weight (g) ÷ Volume (mL) = Density (g/mL).
What type of questions do you have about home coffee roasting. Comment below OR go to my community tab and answer my post!
Video Timeline
0:00 Measure green coffee bean density
0:34 What is green coffee bean density?
1:22 What influences the density of a coffee seed?
4:05 Why should we care about green coffee bean density?
7:19 Have your roasts been impacted by bean density?
8:17 How do I change my roast plan based on density?
11:35 How to measure green coffee bean density
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[@kg-Whatthehelliseventhat]

Hey Mike, After my message this morning i watched many of your videos again. Today i roasted 2 batches of a washed sun dried honduran bean. I did take notes but needed to watch this video to answer my questions from earlier. They look good, much better than those Miramar beans. Thank you so very much. Take it easy.

[@VirtualCoffeeLab]

glad they helped KG. enjoy your Honduran coffee!

[@kg-Whatthehelliseventhat]

@@VirtualCoffeeLab hey Mike, So I weighed out the Honduran beans. I got 207g. 207÷250=82.8 Is this the correct formula? You stated something like this is called a free pour? With the number, what can I do with it? I think you stated to keep track of other beans density numbers and see how they roast. That this is another piece of info to help us roast. The roasts I made the other day are great, they taste so good. Thank you 4 the formulas. My white board is really coming along.

[@VirtualCoffeeLab]

Sorry for the late reply. I've been traveling and got behind on my messages. No, not quite right. You did the weight correctly but not the calculator result. If you divide 207/250 you get 0.828 so your density is 828. you drop the zero and the decimal point. So 828 is a high density coffee. It should be able to handle more heat, shorter dry if you desire and be less prone to roasting defects ;-). Was that helpful?

[@DM-im8th]

I've enjoyed a number of your videos Mike and agree with others here that you provide a great deal of useful information. Thanks for your excellent work! If I may, I'd like to offer a comment about density. The method you've described gives one the free distribution density. A vessel of known volume is filled with freely distributed beans and the beans are then weighed. So if a 100ml vessel is filled with a green bean varietal and the weight of the beans is subsequently found to be 72g then the free distribution density is 0.72g/ml which in your system you are using as 720. For comparing relative densities across a range of beans it is a useful metric and it's not particularly hard to do. Two points are worth bearing in mind about the approach however. Firstly, it doesn't scale uniformly across widely varying bean sizes. This is because within any vessel a much greater proportion of the volume within the vessel will consist of air spaces between very large beans compared to the proportion of air spaces within the vessel when much smaller beans are being measured. Secondly, the density measures provided (e.g. 0.72g/ml above) are not the actual densities of the beans themselves. Green beans sink in water, so their actual density must be greater than the density of water, which is 1.0g/ml. Another method gives actual densities of the beans, accounts for differences in bean sizes, and is only slightly more involved. Take a known weight of green beans and drop them into a graduated cylinder which has a known volume of water. The beans will drop to the bottom and the water level will rise. Record the final volume of water. The bean density (measured by this method it is called the displacement density) is calculated as the weight of beans divided by the difference between the final and initial volume of water. So if one adds 30g of beans to 100ml of water and the water level was observed to rise from 100ml to 127ml then the displacement density of the beans is 30g/27ml = 1.11g/ml. This method scales uniformly across differing bean shapes and sizes and is a measure of density that aligns much closer to real bean density that one can measure with specialised methods and instruments. As you point out in your excellent video, knowing the bean density does indeed help one to achieve more predictable roasting. I find this very easy to do and after measuring a new batch of greens I simply pour them out through a sieve, dry with paper towel and then let them air dry in my shop for a short while before returning them back to my stock. Hope that's worth some consideration and agree entirely with the other comment here about speaking and using the metric system. I grew up with feet, lbs, inches etc. but once you start using the metric systems it takes very little time to see it is just soooo much easier and nicer to work with!

[@VirtualCoffeeLab]

DM, thanks for the great information. I agree 100% that displacement density is more accurate. I appreciate the precise number that will take into consideration bean size as well as density. The part I don't understand is how the weight of the bean will influence the level. It seems as though it is only considering the volume of the object. Let's assume all of the beans sink to the bottom of the measuring vessel. One weights significantly more than the other. How does their weight influence the volume of the water? After many videos, with an audience that is international, I have have started incorporating more metric measurements into my videos. I understand your kind encouraging comment to use the metric system and do see it's value. My current primary roaster is set to display metric measurements and me, the old dog, it trying to incorporate this into all of my roasting. It is a process. Thank you for your patience. Thanks for watching and for sharing. I would like to hear your thoughts on my question related to displacement density. For some reason I don't like the thought of wet beans. ;-)

[@ballentphoto]

Your channel needs more subscribers. Such great information. Thank you very much!!

[@VirtualCoffeeLab]

Thank you for the kind words and encouragement. I appreciate you watching my videos.

[@Diddy0945]

You re the best it's very clear 😊

[@VirtualCoffeeLab]

Thank you! 😃. I'm glad the video helped you learn about how to measure coffee density.

[@MrPBurkett]

Another great video Mike, I have learned so very much from listening to you explain in detail how beans develop in the roasting process.

[@VirtualCoffeeLab]

Hi Paul, thank you for watching and for your encouraging comment. I'm glad you found this video helpful!

[@VirtualCoffeeLab]

One of the things I love about my channel is being able to share what I have learned (and continue to learn) about roasting coffee. An important point about density and Low density coffee conducts heat slower through to the bean center than than a high density coffee. One of my "virtual " mentors is Joe Morocco who, along with Mill City, have shared a great amount of knowledge as it relates to coffee roasting theory. This topic of heat transfer being affected by density is important and there is a lot of old information. I want to be sure I clear up my statement and would encourage everyone to take a look at Joe's very good blog article as it relates to bean density, moisture levels and heat transfer here joemarrocco.com/2016/10/24/coffee-roasting-measuring-what-matters/ According to Joe, he recommends a higher charge temp with very low gas at charge, and then ramping gas back up to a lower setting. Thank you to @daRock1212 for the words of advice for this topic. I am so thankful for the home coffee roasting community!

[@tatekdesta2660]

A more clear approach. Thank you dear!

[@VirtualCoffeeLab]

Thanks for watching

[@RD-ql5ff]

Great job Mike, one more piece of the coffee roasting puzzle to get a more consistent roast

[@VirtualCoffeeLab]

Thanks for watching and for your comment RD. I’m glad it was helpful.

[@Braisbarista]

Thanks for this video, it helped a lot.

[@VirtualCoffeeLab]

Glad it helped Balazs. What are you using to roast coffee with?

[@Braisbarista]

@@VirtualCoffeeLab I'm using a Elecster 500g electric roaster, I'm over 200 cycle of roast so far, but I have to learn a lot still.

[@JimSlaughterOC]

Thanks for clear information on the not very easy to understand subject of coffee density.

[@VirtualCoffeeLab]

You’re welcome Jim, glad it was helpful for you. Do you generally prefer higher density coffee?

[@shanewilson2152]

Hi Mike, great video and information. I liked the method you used to measure the bean density, it was easy to understand. Thanks again Mike.

[@VirtualCoffeeLab]

Hi Shane, thanks! is this similar to the one you made?

[@shanewilson2152]

@@VirtualCoffeeLab not sure what you mean.

[@LivingTheLifeRetired]

Good video Mike, it popped up in my feed to watch again. I was looking around at what I could use for a density tube and opened my coffee drawer and there it was staring at me - my Aeropress tube. A near perfect cylinder. I put a few filter papers in so the water wouldn’t run out, tarred the scale and filled it with water and weighed it. The Aeropress plunger is also really good, slightly smaller volume. I’ll start measuring density next time I roast. Only 13 bags of bad coffee to go!

[@VirtualCoffeeLab]

Density is really helpful. Measuring out your beans and comparing them is really interesting. I find that most of my coffee I enjoy are high density coffees. Great tip on the Aeropress! Thanks for sharing. I use the plastic cups a little for dosing/sharing coffee with family and friends.

[@XMaymoX]

Very interesting, thank you. I'm off to measure the density of all my greens👍

[@VirtualCoffeeLab]

Hi Alan. As you could see on my chart, I drink mostly very high density coffee. I'm a fan of a fruit forward cup! I'm glad you found the video helpful.

[@alimohamad2263]

I have really learnt a lot become have been experiencing under developed roast beans

[@VirtualCoffeeLab]

I'm glad my videos have been helpful. What type of roaster are you using? Are you trying to roast light?

[@aboshooshoo]

Amazing and informative, I really recommend your channel to my friends go forward 👍, I don’t check the density of the coffees i depend on altitude if it’s high the high density if low the low density

[@VirtualCoffeeLab]

Thanks for watching Nawaf. I'm glad my videos have been helpful for you. Thanks for recommending my channel!

[@jonperfetti-tq3fw]

Very nice , I have the same roaster. Little work horse. Thanks for your time and passion for the roasting . I feel the same. Was wondering how much the moisture affects the true weight of the bean and how accurate is the moisture number when buying and storing the beans. Could this be a factor or am I going down that rabbit hole. Weight is weight. Anyway thank you. You have a really nice way about yourself, and explain things very WELL.

[@VirtualCoffeeLab]

Hi Jon, fellow mill city 500 gram brother...... Just so I understand you, are you asking if/how the density score might be influenced by existing moisture in the green beans? If yes, that is a great question. I hope i'm understanding you. My understanding based on "Joe Morocco" from Mill City, says that moisture level in green coffee is about 11%. It can vary by 1-2 percent but generally will be in that range. So, how might density be affected by storage of greens, and ultimately change while the beans sit for months? Depending on the storage wrap, hopefully they are sealed in an air-tight bag or something. This will help reduce moisture from changing much. With regards to roasting and measuring moisture loss after coffee is roasted, the change during storage shouldn't be significant SO, I think it is a fairly reliable and consistent way of measuring your roast level. With regards to measuring density of your coffee, I would strongly encourage you to measure density as a way to know how much heat you can apply to the beans. Of course I would look at the beans, their size, and process as part of your consideration for a charge temperature. This information can help you determine how hard you can push the beans with heat without causing roasting defects. But, I would also look at the altitude the coffee was grown, and also the physical appearance of the seam on the bean. Very tight seems tend to be higher density. That isn't always true though. I was weighing some Sumatra beans with a friend and the seam of the beans was pretty wide, yet they measured as super high density (almost .80 or 800 on my density score. The coffee was grown at 3,000 feet. Regardless, I see this information as helpful although sometimes we just need to roast the coffee and see for ourselves how density influenced our roast I know I elaborated a little there Jon, but this type of information has really helped my roasting. I hope I answered your question? Thanks for your kind comments and for watching my video. Happy Roasting!

[@dg10890]

Great content as always, Mike. I'm still a rookie for sure, but I've had some "happy accidents" in discovering how bean density can affect a roast. I can remember doing a batch of a Burundi followed by a Mexico Oaxaca and was shocked to see that the Mexico hit first crack almost two minutes quicker than the Burundi, all other things being kept the same (batch size, drum speed, preheat temp on Behmor, etc.). In trying to figure out why, wouldn't you know it - the Burundi was a very high-elevation coffee (almost 2,000 masl!) while the Mexico was lower elevation (between 1,000-1,500 masl). Those aren't the only factors at play, obviously, but that stuck out to me.

[@VirtualCoffeeLab]

Hi Duston, I think many of us have noticed similar reactions based on the different coffees we are roasting. If is isn't bean size or moisture content then density may be the factor. Thanks for watching. I'm glad you are sticking at it with your roasts!

[@Presso99]

I am using fluid bed roaster. Here is my experience on higher density beans (Ethiopia Yirgacheffe) 1. High density beans (Ethiopia) has lower first crack temperature, typically lower by about 6-8F compared to lower density beans such as Brazil Arabica. 2. I use the same temperature roasting profile for both low and high density beans, but load 15% lower in weight for higher density beans. 3. Higher density tend to affect the chamber temperature quite substantially (fluctuation) especially during the drying and Maillard phases.

[@VirtualCoffeeLab]

That is very interesting. Thanks for sharing. What type of fluid bed roaster are you using? I'm roasting a high density Ethiopian currently. I found that the bean can take a lot of heat and once i get to the end of dry, it really likes to take off. It is sensitive to heat adjustments and if I'm not careful, get a shorter than expected/desired middle phase (browning). The coffee is moving too fast AND THEN i get first crack that comes early like you have experienced. I have found that if I slow down my middle phase, first crack won't happen much different than my other coffees. So by lowering your load 15% your roast will move faster right? That chamber temp fluctuation you mentioned, do you think that is because the bean is giving off heat? Is that a washed or natural? Thanks again for watching my video and for sharing your experience.

[@daveinnh3410]

Wow! Thanks MIke! I had just started to investigate this question a few days ago and wasn't getting very far. I figured that bean density had to be an important indicator for the roast profile, but I hadn't read or seen anything on it. Now you've given me an answer and a method. It would be great if Sweet Maria's, Burman's, Coffee, Coffee Bean Corral, etc. would list the bean density for all the green beans that they sold. This would be a great help!

[@VirtualCoffeeLab]

Hi Dave, thanks for watching my video. Most of the sellers will list the altitude the coffee was grown. Between that and the origin, you can estimate density. Then, when you look at the bean you can also get an idea of the density and if that matches with the altitude. Ultimately it is measured to confirm. I'm not sure why they don't provide the density? Maybe because moisture levels may vary and affect that measurement? What are you roasting with Dave?

[@daveinnh3410]

@@VirtualCoffeeLab I just got back into Roasting. I roasted with a hacked air popper 15/20 years ago. Bought myself a SR800 with factory extension tube. Plan on installing thermo couples with phidgets and Artisan software. I've joined a few groups on FB and have been watching a ton of videos. Yours seem to be the best, well formatted, good progression of skills and enjoyable. I live in the White Mountains of New Hampshire so no roasting for me until spring, but that's ok as I now know what I don't know.

[@RoastedHVAC]

Thank you!

[@VirtualCoffeeLab]

Wolff is a good source of information. Now that you mention it, I may have seen that video. I'm sure it could be helpful, I've just not used that info. What do they use it for? QC for their roasts?

[@ajk2749]

Thanks for the video, Mike. Artisan software calculates density if you enter the bean volume in the Roast Properties window. My next roast I'll do that as well as figure it manually.

[@VirtualCoffeeLab]

Thanks for watching Adrian. More info to help us improve our roasts!

[@asmith2886]

Adrian, it may be a stupid question but how do you measure volume? I add my beans by weight.

[@ajk2749]

@@asmith2886 A Smith, I weigh the beans first and then put them in a graduated measuring cup to determine volume. I enter that volume in the Artisan roast properties window and it calculates the density. This gives me a way of comparing density of different beans. I've just started doing this so I don't have many different beans to compare yet.

[@GoTellJesusSaves]

Yes. For me, surface area is more important than weight as it applies to how much coffee I can load into my air fryer. I need sufficient surface area for the hot wind to touch on each seed for even roasting. So the less dense the seeds, the less weight I can put in, generally.

[@VirtualCoffeeLab]

Thanks for sharing!

[@GoTellJesusSaves]

@@VirtualCoffeeLab Absolutely!

[@daRock1212]

Hi Mike, excellent info! One point for discussion, I've read the opposite on heat transfer for low and high density beans. Low density beans have larger voids in the cell matrix, and these air pockets slow heat transfer. The roasting approach is the same however, but perhaps for different reasons. For low density beans, the approach is low and slow to prevent scorching as the heat transfer to the inner bean is poor. For high density beans, they can take higher heat without scorching allowing a roaster to speed up drying and get to flavor creation in browning and development more quickly. Thoughts? Thanks for putting out this video, there is very little content on the specifics of roasting methodology, and your videos are always so in depth. Cheers!

[@clindquist16]

You are correct. Great vid but it is incorrect on this point and should be corrected.

[@VirtualCoffeeLab]

Thanks for watching and your comments daRock1212. Great conversation here. I failed to mention moisture level being a factor as far as heat transfer goes. Beans that are more moist tend to require more heat to evaporate. Apparently lower density beans have higher moisture levels ( I wasn't aware of that) and require more heat to evaporate the moisture. Having said that, once the water is boiled away on a low density bean, and it goes exothermic, it really takes off. This goes along with my statement about low density beans being sensitive to heat and really taking off. Again, very interesting conversation here and a little confusing as well. Here are a few references to consider related to our discussion: kzbin.info/www/bejne/i2Gkip-vjrp6lbs Joe Morocco's discussion of the dry phase www.home-barista.com/roasting/coffee-bean-density-and-roasting-t52189.html Home Barista conversation. Scott Rao Roasters Companion (Page 20-21) Thanks again, I appreciate your comments and encouraging words related to my videos. I'm kind of putting myself out there doing these videos with the hope to do more help and not create more confusion.

[@VirtualCoffeeLab]

@daRock1212 and @Carl - Thank you for your comments and correction to my error. I have posted and pinned a correction and it will be visible at the top of the comment section. I will also include it in my description. I also hope to trim out that incorrect statement on the video (if that is possible). Thanks for the encouragement and support of my channel. I appreciate your comments.

[@wenderis]

Hi Mike, watched three of your videos now. Gain lots of new insight. It will help me and probably most of us if we talk in Celcius :D or at least both. Post processing will also affect density, significantly when its wet-hulled. In Gayo, there are some processor that would wet-hulled Bourbon and Abyssinia longbeans. I never really encounter these GBs myself, but a friend of mine, a much more experienced roaster, said that it pretty much drove him nuts. latitude has also similar effect to altitude. beans from Peru or Bolivia doesnt need to be above 1400-1500masl to be super dense for example. Recently got GBs from Yunnan and Sagada grown at 1400masl, they are as dense as a 1700masl Toraja Pulu-pulu.

[@VirtualCoffeeLab]

That's interesting. I wonder if latitude equates to "weather". Cooler nights in higher lattitude? In some of my recent videos I am displaying both F & C for temps. See the "Behmor Profile Coffee Roasting" video. Thank you for you insight, comments and for watching Adolf. I think the high density washed is a challenge to roast, but i'm having fun!

[@wenderis]

@@VirtualCoffeeLabyes cooler night, but also more prone to frosting in >15n or >15s latitude. Oh, yes. Hooray, thx. No need to open a separate chrome tab. No..no.. not washed aka the usual wet processed beans but wet-hulled. They couldnt be further apart in the resulting cup. Abyssinia (AB3) and Bourbon from the Gayo region when wet-hulled, they say, provide weird roasting challenges for reasons above my present pay grade. Perhaps, one of the reason is moisture level with these beans are usually above 12%

[@robertebob]

Thanks to you I know I have a 714, 718 and a 726.

[@VirtualCoffeeLab]

Nice. Are those Central or South American beans? Those variations won't really be that noticeable when it comes to roasting. The bean size, process type are also considerations how heat will affect your beans while roasting.

[@robertebob]

@@VirtualCoffeeLab The one with 726 density is Honduras Marcala 18 Rabbit Natural and the 717 is Haiti Singing Rooster Baptiste Blue washed. Both are size 15-16. I have some Kona Private Reserve on the way that's 17-18 in size, so yes, I'll be considering that and its density as well. I'd love to see a video about expectations of density after roasting, please. Knowing what density to expect after roasting is somewhat of a mystery. Thanks.

[@VirtualCoffeeLab]

Density is measured before the roasting process so we can plan our roasting approach. Moisture loss (not density) is measured after we roast our coffee. This measurement helps us understand our roast level. There is a correlation between bean temperature and Moisture Loss. So, we use bean temperature, moisture loss AND bean temperature to help us understand roast level. It is also used to help us with repeating the same roast level consistently. There are other indicators but that isn't fhe focus here. I just wanted to clarify how I use bean density to roast coffee. Maybe I am missing something but I don't think I have measured density after a roast. That could be interesting. I roasted a Maragogype this past week. This varietal is a big bean that swells up bigtime during the roasting process. It is so big my grinder has a hard time grinding it. I should measure the density of that bean. It kind of reminded me of the monsooned malabar (size wise).

[@robertebob]

@@VirtualCoffeeLab Wolff Coffee Roasters has a Roasted Bean Density video which put this thought in my head. I wasn’t sure if it was a thing.

[@marciosanglard8695]

One more good topic you presented and nice video that makes us think how to manage roast. I would like to point for discussion that once we have great differences on bean size, we are comparing the density of the batch more likely than the density of the bean It selfie, because of a geometrical factor. It impacts the moisture content relation reference. Larger the Bean more space between them, less compact the batch. This way, I think we have an influence of the size of the bean on measurement, leading to lower values for larger green beans, does It correlate?

[@VirtualCoffeeLab]

Hi Marcio, yes, I think I understand what you are saying. Basically, larger beans take up more volume and may have bigger gaps in the mass that is being measured and this might skew the density results. Then the moisture factor also influences the results. Yes, I agree. As far as how that affects how we roast the coffee it is all good information that helps us in our approach to the roast including charge temperature, roast profile and what we might expect for bean behavior while we apply heat and the moisture evaporates from the bean. Great points you bring up and important for all of us to consider. Thank you for sharing!

[@mmortada1978]

Yes I faced I got guatemala its small beans but it's high density it's took about 17 minutes for Roasting 230 grams I got also Colombian beans low density 190 grams at 11 minutes I tried also Nicaragua beans with big beans and a hight density 230 grams took about 21 minutes

[@VirtualCoffeeLab]

what are you using to roast your coffee?

[@JackSmith-lt4vz]

I was wondering if moisture would have more of an effect, if a high density bean with 9% moisture and a high density bean with 11% moisture would the 11% moisture bean roast more like a medium to low density bean as it will conduct heat better? Or would it not be as significant as just the density of the bean? I would guess density matters but what makes up that density also matters, I’m not quite at the stage of measuring all of these variables yet but it’s super interesting, so far I have a basic profile I run on all my beans as a test roast (100g) to see if the roast needs to be longer or shorter and then adjust from there but I’m guessing by testing density first and moisture I might be able to jump right into a profile that would be 80% to 90% correct for the bean. Definitely going to test density today!

[@VirtualCoffeeLab]

Hi Jack, great point. It is very interesting and I am not experienced enough to give any definitive perspective comparing what is more effective. I agree that moisture is another part of understanding our coffee and how it may respond to heat. I measure moisture loss from green to roasted beans, but I don't have a way to measure moisture level of my beans. Do you? What do you use? Take a look at this really interesting post by Joe Morocco dealing with this topic and let me know what you think. joemarrocco.com/2016/10/24/coffee-roasting-measuring-what-matters/ In a nutshell, Joe says: I" would argue that this difference in moisture does not matter to how heat is transferred to the coffee. The density of the coffee DOES matter to how heat is transferred to the coffee. The physics of heat exchange are such that: heat transfers more quickly (conducts) through more dense objects, and more slowly, (is insulated against) through less dense objects.* Therefore, density is key." I appreciate the discussion and want to learn more about this topic Maybe I need to buy a moisture meter? Let me know what your testing revealed. Thanks again for your comment and for watching my video!

[@michaelmiller465]

Thanks for another great video! I just measured the density of the three beans I’m working on currently (Dominican Org, Brazilian Mogiana, and Congo Kivu) and to my surprise they all weighed within 1-2 grams of each other, leaving the bean density practically identical. Is that close enough to initially do the same roasting profile on all three per do I need to adjust over 1-3 grams over a 200 gram sample?

[@VirtualCoffeeLab]

Hi Michael, Initially....... yes. Density is one way to determine how you will approach the coffee. Also look at the bean size and processing. Small beans will require you to be less aggressive with the heat. Then there are the tasting notes and your own personal goals for a flavor profile. So, technically you should have similar results as far as temperature, color and the overall roast level. We haven't discussed the existing moisture level in the beans, how old they are and where they have been stored. These factors can cause your results to vary even when you use the same profile.

[@michaelmiller465]

Much appreciated. There are definitely differences in bean size among the ones I have on hand. I’ll have to check with the supplier and see if the other information is available. Thanks again!

[@VirtualCoffeeLab]

i don't think you need to be that precise Michael. Generally are the average size beans, very small beans or large beans is the idea. If you are going for origin flavor and not a darker roast then using the same profile to start should be good enough. Based on the coffee you mentioned, it sounds like earthy, darker notes like nuts, chocolate, and maybe a little fruit are in those coffees? Also, the altitude for those coffees are probably not really high and most likely something like 1,000-1,500 meters above sea level. So, if they are similar you have a better chance for them to behave similarly using the same profile. There will probably be some adjustments to your heat needed between these coffees. The only way to know is to chart your roasts and compare times and temps.

[@damianreed1990]

Thanks for the very well done video. I am curious to know what the altitude of the farm is where the Monsoon Malabar came from. I would imagine a quite a low altitude say around 700-900 meters?

[@VirtualCoffeeLab]

Hi Damian, thanks for watching and your kind comment. I have roasted a monsooned malabar coffee and it is a "freak of nature" so to speak. It has a super low density and i believe the process has something to do with it as well as the altitude. So, the coffee I roasted was grown at about 1200 meters. My density score on this coffee was in the high 500 range I think? It was really big yet very light. It you look at this video ( kzbin.info/www/bejne/fJWcenSfhLWooc0 ) at the 5 minute mark and you can see the difference in the center line. It is wider which also indicates a lower density coffee. It was a difficult coffee to roast compared to most i have experienced.

[@damianreed1990]

@@VirtualCoffeeLab Your welcome, it is always great to share this passion with others. The wider center line is why I asked about the altitude. My farm is at 1200 meters and the beans are never that wide.. Like you say, a freak of nature. Could be that the farmers didn't use fertilizers. That would affect the density for sure. That's the great thing about coffee. Altitude although important, is not the final word of what cups well. My tipica coffee would score 85.5 - 87 3 years running. Great flavour notes mimicking geisha with very noticeable lemon characteristics. No one knows everything, there is always so much more to learn

[@garystepp1054]

Hey Mike, good info. So what altitude ranges define low density vs high density beans?

[@VirtualCoffeeLab]

Hi Gary, Density isn't just about altitude, but temperatures, moisture and maybe even the varietal. Generally speaking, the higher the altitude has cooler temperatures and less oxygen which causes the plant to grow slower. This slow growth of the seed creates a really solid, dense bean. These dense beans tend to be more sweet. Coffee grown below 1200 m.a.s.l. (meters above sea level) is considered in the lower, softer density. Between 1200 - 1370 is considered a medium density. and above 1370 meters we start to get into the high density beans. There are actually other ways they describe density, which is hardness. Low Density SB - Soft Bean ( grown below 1200 meters) SSB - Strictly Soft Bean ( grown below 1200 meters) Medium Density HB - Hard Bean ( grown between 1200-1370 meters) HG - High grown (grown between 1200-1370 meters) High Density SHB - Strictly Hard Bean (grown above 1370 ) SHG - Strictly High Grown (grown above 1370 ) This is my source article for the data above. perfectdailygrind.com/2021/08/understanding-coffee-bean-density/

[@erharddinges8855]

Yes density is important for the whole process. --- Did you success in refreshing old greens by spraying water?

[@VirtualCoffeeLab]

Hello Erhard! No, I have not had time to experiment with the spraying of water on the old greens. I will let you know when I do. It has been a very busy time for me lately with work so I have limited time BUT hope to try it soon. Thank you for asking.

[@erharddinges8855]

No problem, there is no priority! Did you you watch the channel "coffeemind"already- this is a channel from Danmark where they try to simplify coffee on a scientific basis.

[@HaiHoang-bk5or]

Tks Mike! How to rescure roasting defects cases?

[@VirtualCoffeeLab]

Hello HaiHoang, I’m not sure I understand your question. Are you asking how to prevent roasting defects? m.kzbin.info/www/bejne/j5eQoKONrZ6HfqM

[@HaiHoang-bk5or]

@@VirtualCoffeeLab yes sir! :)

[@VirtualCoffeeLab]

ok, then the link to this video m.kzbin.info/www/bejne/j5eQoKONrZ6HfqM gives a really good start to understanding roasting defects and I would suggest you watch that video. Feel free to ask more specific questions.

[@larryb51]

I went ahead and compared the densities of my regular and decaffeinated Columbian, and sure enough, the regular is less dense. However, I also noticed that the decaffeinated coffee lost more mass in water than the regular beans. This leads me to believe that higher density in the decaffeinated beans is due to a higher water content, at least for the water process decaffeinated beans.

[@VirtualCoffeeLab]

Hi Larry, that makes sense to me. What was your lowest density coffee and what was the number?

[@larryb51]

@@VirtualCoffeeLab My measurements were a little "quick and dirty" just to get a comparison and test my hypothesis. As I recall, the decaf beans were 160g/236 mL (678g/L) and the regular beans were about 150g/236mL (635g/L). But I want to actually measure the mass reduction before and after roasting each. This will happen next weekend as I have enough coffee for the week.

[@larryb51]

I repeated my measurements more carefully today and found that the difference in density is too close to determine using the method given. I filled a measuring cup to 250 mL and measured the mass. Decaf Col: First trial: 195g/250 mL (0.78g/mL). Second trial: 185g/250mL (0.74g/mL). AVE 0.72g/mL. Reg Col: 187g/250mL (0.75g/mL). However, I measured the mass reduction for the decaf today: 198g to 167g. I was keeping the roast controlled at about 270°F watching the "A" temp rise up. The "A" temperature got up to 360°F a little sooner than I'd have liked and as a result it reached 2nd crack about 30-60s before I was planning. (I was trying to roast as high as I could to get the caramels out without getting into 2nd crack.) %loss = 198-167/198*100 = 15.6%. Next time I do the regular Col I'll measure the %reduction to compare. I'll also sacrifice a few beans of each and measure the density by displacement. This will be tricky because the beans are less dense than water (0.8g/mL vs 1g/mL).

[@VirtualCoffeeLab]

Hi Larry, So if I understand you correctly, you are trying to determine roast level by moisture loss right? You mention you are trying to get as hot as you can for carmelization can you share your phase times with that Colombian coffee. I'm curious to know what they look like.

[@larryb51]

@@VirtualCoffeeLab Sorry, I never tried to imply that I was trying to determine roast level by moisture loss. Ultimately I just want to compare moisture loss of the decaf and reg Col, and also intend to more accurately measure the densities of each. I only mentioned the roast level in case some one was trying to compare results.

[@BattleAx342]

Hi Mike I am new to roasting coffee I just received a Huky 500 about two weeks ago and have about 9 roasts on it. My question is if the coffee is high density do you charge at a higher temp or lower temp? Thank You

[@VirtualCoffeeLab]

Congratulations on your new roaster Frank. Because you have a high density you can roast using a higher charge temp. You don’t have to. Lower density coffee usually charges at a lower and then ramp up temps. They do that to reduce roasting defects like scorching and tipping. How long is your dry time with the Husky?

[@BattleAx342]

@@VirtualCoffeeLab Hi Mike for the Ethiopia coffee it was about 2 min. I put my profiles of the roast on Barista forum and they told me to charge the coffee at a lower temp I was charging at 428. I am going to try 400 to 395 and give that a try. Thank You

[@VirtualCoffeeLab]

Frank, i would suggest you don't just focus on the temperature for charge. Everyone's temps will be a little different and it will give you slightly different results. To determine a good charge temperature for that specific coffee for your roaster, in your environment, consider using the time it takes to get to dry end as your gauge. Aim for a dry time of about 4 1/2 minutes. So, all yellow, no green is how I know I have reached dry end. Along with that, consider using about 80% power/fuel during dry unless your roaster can't keep up and then you will have to use more energy. Be sure to pre-warm your roaster for a good 15-20 minutes before roasting. Get your roaster to the right temp for charge that will get your coffee to dry in 4 1/2 minutes. You will feel more in control and set yourself up for a nice middle phase on your way to first crack. Just to get a starting point, consider a first crack time around 7 3/4 minutes and then with a ROR that is still descending target your drop around 9 min and 30 seconds. Try that recipe. it will give you practice to control your roaster and the pace of your roast.

[@luigicollins3954]

Nice Mike! Just the kind of video an engineer likes to see! I'm not sure what to do with my density data (see below), especially if there is not a lot of variation between coffees. Since I'm currently using a Behmor roaster, drop temperature can maybe guide me on pre-heat temperatures. I can't recall if you stated it, but does the density give some determination on total roast time? I know the roast time can be varied to have different characteristics of the coffee come out. But are there any basic attributes like high density coffees have slightly longer roasting times and low density coffees have slightly shorter roasting times? You know me, I just couldn't wait to measure density for coffee in my current inventory. All appear to fall into the high density category, with Columbia measuring lowest density and Costa Rica measuring highest. So here are the numbers: Columbia 705 Costa Rica 769 Nicaragua #1 710 Nicaragua #2 722 Guatemala #1 753 Guatemala #2 745 El Salvador 734

[@VirtualCoffeeLab]

Hi Lou, thanks for your comment and for watching my video. I think with the behmor and the slow ramp up of temperatures it doesn't have much of an impact as far as the dry phase goes. I made an incorrect statement on my video (which I am correcting) where I said the lowered density bean has a faster heat transfer when in fact it is slower. It is more prone to roasting defects and sensitive to heat later on near first crack as it goes exothermic. I'm still for shorter roast times on the high density coffee. The 4-6 minute window for drying is a good range to get enough time in browning and development for a nicely developed roast with well rounded acidity. The only low density bean I had was the monsoon malabar. Everything else is high density. We have similar tastes in coffee! ;-) So in short, if your roasting high density exclusively then keep doing what your doing. When you start to roast lower density coffee and you have determined it is low density by measuring, then be cautious o roasting defects and if using a drum roast, go low on gas for the first minute or 2 and then begin to ramp up the energy. Hope my response was helpful.

[@bishwobandhupokharel9528]

Hi namaste good morning I'm from Nepal 🇳🇵. My question is how we can measure it at home

[@VirtualCoffeeLab]

The instructions are given at this point 11:50 in the video. Measure 250 grams of water by weight into a plastic cup. Then draw a line around the cup at the water line. This is your fill line for coffee beans. Read that weigh and divide that by 250. The result is a decimal number. Just remove the decimal and use the first t numbers. Example would be 0.768 and this would use just 768 as your number . Low density will be 500 and super high density will be 800

[@rushaddaruwala7568]

Eureka

[@VirtualCoffeeLab]

Thanks for watching Rushad. Sounds like my video was helpful. I'm glad!