Extract Everything 006: Coffee Refractometer Basics | Measuring TDS + Extraction Percentage

[@em0verload]

Great video! My only question is why use distilled water to tare your TDS instead of the water you used to brew with? Tap water will have its own TDS so wouldn't that interfere with properly measuring the coffee TDS?

[@pje3325]

Accuracy - Because you need a background. Particulate may still exist within water from some filters depending on quality

[@Legzakimbo2002]

@@pje3325 I disagree. The video implies that you test how strong your coffee is via tds, total dissolved solids within the water. If you calibrate the meter with pure water, I.e. 《5ppm then use tap water(which can have upto 500ppm TDS) to make the coffee, where are your true readings going to be? It would be much better to calibrate with tap water and then any extra tds measured after testing with coffee is provided by the added coffee only giving a much clearer and accurate indication of strength.

[@Silverskin21]

Exactly my question. I have atago refractometer and it says to calibrate using tap water. Which is the correct way to do it?

[@calabrais]

This is a great question, but my counter question would be: do you know how much of the TDS from your tap water is making it into the coffee? Maybe some of it is absorbed by the coffee grinds? I would be more comfortable calibrating the device with distilled water to keep it as precise as possible, then getting a reading of the tap water, and subtracting it from the coffee reading.

[@jz2450]

I love how concise this video is. so informative too

[@baharga1893]

November 2021 and still relevant 👍

[@izmirfariz]

When you added that sentence, "This is not a cheap tool", I couldn't help but smile.

[@RealChrisBaca]

It's definitely not cheap!

[@ericnadler790]

Yes, I like how you were very diplomatic about that. "But it is the industry standard" pretty much sums it up. Listen to Chris' podcast if you want a hotter sports opinion. ;)

[@inJCwepray]

Hey Chris! I'm sure someone more senior may disagree with me on this, but speaking from a research background, I'm not sure if finishing off with an alcohol wipe is the best way to go after zeroing out. Wipes can leave behind residues after all the volatiles have evaporated, and although it's likely imperceptible to the TDS of your sample, you're ultimately adding more variables into your workflow which could take away from a consistent reading. After zeroing with distilled water, I think wiping away with kimwipes or another lint-free towel is all you really need. That being said, I'm sure this is a process you've followed for many years to your success, so I can't say what you're doing is wrong - clearly it's worked for you :) Thanks for the vid! Super thorough!

[@RealChrisBaca]

I'll run it by Rao and see what he says ^__^

[@inJCwepray]

Haha tell him I say hello

[@ericnadler790]

Yeah, I would be curious to know also. I don't always use alcohol wipes but when I do I just use them before I start and when I'm done. Usually I just rinse before and after with the distilled water. I do love the Kimwipes off Amazon. I hope they leave less lint behind than a paper towel. I'll use about 65 for each measurement. ;)

[@seetubemetube]

2020 and still relevant! Thanks for the upload 🙌

[@ebenburger111]

If I understand this correctly, there's a very simple way to get an average extraction yield. Weigh the Original dried ingredient you'd like to extract. Infuse your dried substance and filter. Now dehydrate the remainder Fibrous content to get rid of most of the water - comparable to its original state, and Weigh it again. The difference in weight before and after the infusion of the dried matter will show you how much extracted content you now have mixed within your liquid. For example, if the dried coffee was 100g before extraction, and after filtration and dehydration is 60g, the total dissolved/extracted content is 40g.

[@DiegoNunes]

Theoretically. In practice is harder to measure accurately the leftover mass, because the difference would be really small and there will be some mass of the insolubles carried to the cup and stuck in the filter.

[@timothybracken1728]

WOW this was extremely helpful for beginners, thank you Chris! !!

[@cheekster777]

The bonus scene you tag on at the end of your videos are dope yo! :)

[@RealChrisBaca]

Thanks homie!

[@matthewwomack7901]

Chris, looking around, you can catch a refractometer on the cheap. At least, cheap compared to the VST. Do you know if these would work if I'm willing to put in the MATH to do it, or is the VST running some crazy proprietary bidness that is under lock and key keeping these delicious coffee number secrets at bay? I'm just a regular dude, no barista, but I'm into the idea of taking tasting notes, establishing base lines, being able to compare those numbers from coffee to coffee, finding trends, etc., yadda da. Can it be done by normal people with normal equipment?

[@jaeadams1858]

Socratic Coffee did a write-up and comparison on the Atago Pal-Coffee refractometer against the VST-Coffee you should check it out. Other refractometers don't cover the same scale of temperatures and TDS with the overall measurement accuracy that you would need in order to produce decent results with coffee.

[@matthewwomack7901]

Jae Adams i will check it out. thanks dude!

[@ryansaunders571]

have you ever considered doing a video on the vst coffee tools app. i'm having some issues with getting in the "ideal" range as set forth in the app. since my measured brew weight is less than my original entry, i can't every get my blue circle to match up with my red circle. i'm sure it's a common problem and even if it's not, a how to for the app is definitely something anyone watching this video would find useful. either way, keep up the good content!

[@drewmcneice7986]

why would you use distilled water to calibrate? wouldn't you then be measuring your extraction yield PLUS dissolved solids present in the brew water? If you calibrate with your brew water aren't you more accurately measuring only the coffee solids dissolved? If I'm missing something here please clarify it for me 😀

[@inJCwepray]

You're calibrating the lens to register what "0" is. If there are residues left on the lens from a previous use, this could alter what your coffee's true TDS is. Calibrating with your brew water is NOT the way to go as then you're standardizing total dissolved solids across only THAT sample of water, which would lead to very inconsistent results across multiple measurements. TDS measures total dissolved solids, including any particulates which could be in your brewed water as well as your total dissolved coffee. Distilled water is nearly pure, whereas your brew water likely is not. Hope this helps!

[@drewmcneice7986]

turbo_powahhh does the vst algorithm/app account for solids in the brew water then? because if it's going to spit out a number that represents extraction percentage i feel like it would need to

[@inJCwepray]

I don't believe so. In a nutshell, refractometers capture the amount that light "refracts" (essentially the angle at which it changes direction) to whatever substance is sitting on that lens. In brewing coffee, water is the solvent and so the contents of water can affect the solubility of your desired solute (this case being coffee). Zeroing out with distilled water provides a means for the device to know what a blank slate is. Since your water content can change/is probably inconsistent, this affects the level of solubility of all total dissolved solids in your cup. This is a standardization that allows for everyone to play on the same field.

[@drewmcneice7986]

turbo_powahhh I understand how refraction works, however it's this inconsistency in brew water samples that leads me to be skeptical of the practical use of refractometers in most cafes.

[@RealChrisBaca]

You definitely need a consistent brew water supply for the most consistent results. We R.O. everything then add the minerals we need back in to pull what we need out of the coffee. It's heavy, but worth it.

[@danwilson4355]

wait.. you're filtering the sample? how do you get an accurate dissolved solids count if you're filtering the liquid? wouldn't there be an inherent loss of material to the filter?

[@justicesky9978]

If they’re dissolved they won’t be removed by the paper filter. The non-dissolved solids will be removed though.

[@dominikpaulke4097]

The question I have is why would I filter something out that I usually drink and that is probably part of the taste?!

[@SignalDitch]

@@dominikpaulke4097 Because you're not measuring the taste, you're measuring TDS, and insoluble material will interfere with the reading. Since you only get one number out of the process, you really only want it to represent one variable. In this case, we're interested in the extraction, not the efficacy of your coffee filter/screen/press/decanting method. Insoluble material _does_ affect the experience of drinking coffee, you're 100% right (which is why we see some insoluble material included in higher-end instant coffees even though they're not inherent to the process) but if you want to track those (which would be interesting, I don't know how many people are doing this) then you need to devise another test. A good starting point might be to weigh the syringe filter before filtering the coffee and then dry it out and weigh it after to determine how much material was caught. All that said, a lot of people won't filter the coffee and if you're dialing in an espresso or something like that where you're only comparing a coffee to itself and the brewing process isn't changing very much between shots, I'm sure it's fine. If you're doing QA, you probably want to filter.

[@xafafx]

Why didn't I see this video when I was studying about coffee, it could have been a great help, cow studying all this in Korean gave me a headache 😑 Anyways, great video, good to review my classes 🥰

[@Anggaditto2]

Hi Chris, have you ever compared, with same number of TDS, but with different parameters (grind size, ratio, water temp), how do they taste? Do they have same notes?

[@priskokeen]

Man, its most likely videos about the coffee, on your channel. Keep going in the same way :)

[@RealChrisBaca]

Will do my man

[@cipriandragoi9166]

Hello Chris Baca. How often do I need to calibrate with distiled water ? every time before measurement ?

[@tesha8202]

Hey. is the bev weight in 3:36 the total coffee weight after brewing ?

[@guytzur9120]

Hello what is the size of pores syringe filter? there are few sizes like 0.45 and 0.22 micrometer

[@morningmotivations2661]

Hi Chris how do you relate solubility of your roasting to a way to do your QC? By means of tds?

[@vizzo7]

hi, my tds meter reads ppm. I got putting it in the coffee 1560 ppm. what do i do now?

[@Yirgamalabar]

I have a simple brix refractometer that I use for beer brewing. Is it also usable for measuring coffee extraction?

[@Anggaditto2]

I also use analog brix meter. It is not as accurate as the digital one, but it is usable to approximate your brewing result. Also you need to convert it by multiplying with 0.85.

[@ibrahimelsisi]

When you say final brew beverage , is that what u get in ur cup ? For instance if in v60 I poured 390 ml of water over 23 gram of coffee and the final output is 340 gm, is that what I shall use in the calculation ? 340 ?

[@RealChrisBaca]

yes. in the VST app you can set it for either end beverage weight, or water used to brew. I usually use end beverage weight.

[@rybackaquiza]

Can i use wipe replacement fot alchol wipes?

[@ZeroCool1point6]

I would love to get the app so I can learn more about this but man so out of my budget :( Hey Chris, I will be opening my own cafe down in Canberra next year. I would love some good tips on some stuff.

[@danesebruno]

Thierry Ferreira aussie market is awesome. Customers are knowledgeable and demanding. What machine and grinders are you getting?

[@ZeroCool1point6]

Actually I don't know yet. There are great machines out there!

[@danesebruno]

Thierry Ferreira SO many options, right?

[@ZeroCool1point6]

Bruno Danese yes so many these days. its good tho.

[@danesebruno]

Thierry Ferreira the more options the better. Five Senses seem to be a great company, check them out.

[@DanteKali]

Does this work on tea too?

[@enricogironi3426]

Can I filter espresso with v60 paper??! Or syringe filters is necessary?!!

[@InversionesLamo]

Amazing Chris, are you gonna attending the Global Specialty Coffee Expo ?

[@RealChrisBaca]

Thank you and yes! I'll be there!

[@vitomunoz1002]

Would this measure coffee extraction in a coffee extract? Ground coffee, Vodka, time..

[@davidthuman8475]

Wow thank you, you made it so simple now. :)

[@RealChrisBaca]

You're so welcome

[@alvinbano7510]

I think 1.55 TDS is too high! But it's just a guide though and its all about the actual taste.

[@sbokhumsook1494]

example : TDS (1.4) x Final Brew weight (288) = Number (403.2) Number (403.2 ) / Dose (18) = Extraction% (20.73) why it is not 22.4 ?

[@Anggaditto2]

Where do you get the number 20.73 from?

[@sbokhumsook1494]

@@Anggaditto2 this vdo on 3.19 minute,when use VST app to calculated.

[@Anggaditto2]

@@sbokhumsook1494 288 is the not the final bev weight. It is the brew water weight. The final bev weight inputted by Chris is not shown in this video (line below brew water weight). As my experiences, it is around 0.85-0.92 x brew water weight.

[@Anggaditto2]

So if we wanna do reverse calculation, we can estimate the final beverage weight that Chris get is 266.5 gr

[@sbokhumsook1494]

@@Anggaditto2 Oh I already understand. thank you very very much.

[@Leo-wm7cd]

So Extraction percentage= TDS x yield / dose Yield / dose= grams of water used to brew one gram of coffee wich is found in your brew ratio like 1/2 , 1/3 ,1/15, etc So Extraction percentage = TDS x second number of your brew ratio

[@Anggaditto2]

I don't think so. What do you mean with yield? It should be "final beverage weight". For example, 15gr ground with ratio 1:15, brewing water weigh 225 gr. From that 225 gr, few will be absorbed by the coffee ground, so the final bev weight usually around 190-205 gr.

[@angelabuenafeYT]

This is IMO next level nerd!😂 i like!

[@barisozcetin]

was there any difference between readings with syringe filter and without filter assuming that was filter coffee not espresso?

[@kmervau]

I had the same thought. I was under the impression that the screw on filters were for immersion methods (that don't have a paper filter at the final stage) or for espresso since all other methods would be already considered filtered.

[@RealChrisBaca]

Yeah you technically don't need the filter for filter coffee as the brewing filter does the job. For espresso and immersion you definitely need it.

[@ericnadler790]

I don't use filters for filtered coffee. A lot of times I also don't use them for immersion or espresso either, since they are expensive and I'm just looking for a number I can relate to taste. Socratic Coffee also did some experiments with and without filters and they do not use filters normally. Using a filter will just lower your TDS, so you just need to understand you might be getting a falsely high reading without one. But keeping it consistent without a filter still helps me dial in espresso as a home barista to see which way I'm moving the extraction and strength. Also, you can find some filters cheaper than the VST ones if you do want to use a filter.

[@josephalayoubi-monett177]

RealChrisBaca Any advice on cheapest place to get the syringes and filters?

[@MakTVPlukman]

Thanks for this Sir Chris. :-)

[@RealChrisBaca]

You're so welcome!

[@maironderocha]

What's the name of this app? I don't understand, i'm a brazilian, my english is more or less. 😊

[@RealChrisBaca]

VST CoffeeTools

[@maironderocha]

RealChrisBaca tks☺

[@scarlettvannispen3216]

Why do you use a filter on the syringe?

[@Kaffeemacher]

to make sure that only the solution is measured. whe brewing with paper filter you dont have to do so. when brewing espresso or french press, particles are in the cup and mixing up the measurement.

[@morningmotivations2661]

Hi Chris thanks for another informative video tutorials. May I ask why is it that when I do my manual calculation for extraction % is different from the extraction % given by vst app? thanks in advance.

[@morningmotivations2661]

dseng hi there i will definitely try.. thanks for info

[@morningmotivations2661]

it worked! thanks a lot!!!!

[@RealChrisBaca]

Yup what they said.

[@sdfgsdfg9549]

No thanks. I'm not game to use this every time I buy 250g or even up to 1kg beans - its too TDS to use. Plus there are too many variable at play to justify this unless you are in a commercial space.

[@henriksorensen82]

But Chris, what if I get to the magic number 42. With that joke out of the system. Thank you for taking the time to make these vodeos, I know it is time consuming, so I'm very happy that you do.

[@RealChrisBaca]

You're so welcome. I'm glad you're getting some use out of them!

[@petercybercop]

Chris We need to talk

[@firmbutton6485]

Why do this?

[@Figgboii]

I love how he doesn't put a link to the refractometer in his description. lol, fail.

[@kondko]

store.vstapps.com/products/vst-lab-cof-esp-iii-refractometer here you go

[@SlimBarista]

And then there are other people who complain about affiliated Amazon links in the description. Seriously dude, don't you know how to google?

[@Eklektik190]

Can someone gift me one of these babies?