How to Measure Alcohol Content 

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The MBAA podcast had a recent episode comparing 4 different density measurement methods. They found the "homebrew" hydrometer to be the least accurate and least precise, but also the cheapest. The refractometer performed much better, although they were using a pro model (not the cheap plastic ones homebrewers use), and clearly knew how to correctly convert the refractive index to density.

Segal's Law: “A man with one watch always knows what time it is. A man with two watches is never sure.” I calibrated my iSpindel using two hydrometers, a refractometer, and I used a 0.01g scale for the sugar, 1g scale for the water. Tested the temperature with two alcohol thermometers, two thermocouples, and an IR thermometer. None of them agreed. I went with the measured density from the scale as I could verify it's accuracy using calibration weights. We're making beer. If you're not selling it then you want to know roughly what the ABV is so people can make informed decisions, and you want to know when it's finished/if you have any problems. My iSpindel is now accurate enough by itself for both those purposes.

Different than this but I was looking up seltzer stuff on google and I guess one of the frequent questions they have was how to make seltzers at home and another one was how do I start making seltzers and google was providing a link to your seltzer video. Thought that was pretty neat.

very good info!😗

I, too, have an alcoholomometerizorator. Excellent.

I thought I would upgrade to a refractometer when I broke my hydrometer. Great for your starting sg but found final sg to still be high ( hydrometer showed dry, your miles may very). Great for a backup or salt water tanks.

I'd like to see you do a side by side to compare these methods accuracy, cost, and faff: Use 100% fermentable sugar. An accurate 10.00g in 1000ml of water, for example. Record temperature. Check and adjust calibration of any devices that require (refractometer). Take your OG measurements. Record temperature. Let it ferment out. Get it to the same temperature as it was. Take your final measurements. (including mass and volume) Refractometer reading needs to be "corrected" because sugar has been converted to alcohol with a different refractive index. Quantify how much they disagree. You can then throw in some noise factors to see how big a difference they make. Variables like: Add food colouring (often alcohol based, so check this. A small difference in density is expected) Add an unfermentable soluble element. To raise FG without affecting colour or alcohol content. High water salts or unfermentable sugar like Lactose? Temperature. Noting the reported SG, and the corrected SG. How expensive was your device? An expensive refractometer might be more accurate than a cheap hydrometer?

unrelated, but you guys should release a video where you try and clone the Mural Agua Fresca Cerveza made in partnership with New Belgium. Been messing around on my own with no success, so figured you guys are smart enough to come up with something.

I'm a fan of using a regular hydrometer for getting SG while brewing. During fermentation, I use a Kegland Rapt Pill Floating hydrometer in conjunction with their temp controller. Ton of control over the whole process and the price for the controller and the floating hydrometer is under 200 bucks. You can also link the temp controller to Brewfather or others and have all the data logged. The Pill floating hydrometer is pretty accurate once calibrated and gives to a ton additional features such as controlling temp of fermentation chamber by SG... Awsome for creating a profile to raise the temp at the end of fermentation biased on SG and then have it cold crash automatedly after a few days.

Holy. This answered one of my biggest headaches about brewing beer. I just couldn't wrap my head around it. Ver VERY well explained. Now I understand. Thank you!

IMO it's horses for courses: I'm not doing a hydrometer trial before I chill the wort, but it's useful to know how extraction and sparging are going, along with if you need to adjust the boil to hit target OG. A refractometer is more useful for that because it's thermal mass corrects the temperature faster than a hydrometer can get results and with less faff and I only need approximate figures. Then I use my iSpindel for OG and fermentation, with refractometer to sanity check. FG I'll use the refractometer with a correction factor. Hydrometer if the alcohol measurement actually matters, in which case I'll have taken an OG with it as well.

I use both (hydro and refrac), but after pitching the yeast it is all hydrometer. The other thing I do is calibrate the refractometer to the water I use. Not distilled water. If you are brewing with distilled water only then that is fine but I don't believe most people are. I filter my brewing water and sparge water and that is my starting point. Not distilled because I'm to cheap to buy 10 gallons of it. Like Kyle says I have done many brews and there is a difference from the two readings, but after time they have came out close to one point away. I won't give you any hate for the vid. We are all on a journey together to try and make the best beer we can with what we are given! Knowledge is always evolving and for someone not willing to try is where we fail in the hobby. I have brewed so many good beers and also bad ones but that is how we become better, because of the community and videos like this where what works for you may not work for the other person or be in their budget. Keep brewing everyone!

By the way: ABV label on beer does not have to be accurate to 0.1% the requirement is that they need to list it to within 0.1% with tolerance of +/- 0.3 so in your test the accuracy of the meters +/- 0.3 and with a 0.05 rounding shows they are both in same tolerance range.

Dammit. I knew something has been a bit weird cuz I never ever get anywhere close to the same mash efficiency ever since I started using a Refractometer. I thought they were fine for OG readings but after watching this I’ll just stick to my hydrometer for both OG and FG. Thanks for the info! Cheers!

My Refractometer says 1.049 .. Correct value 1.043 ... I'd say your analysis is correct!

Moving my comment over to this one because why not So here's why I use a refractometer. I've tested it against my hydrometer and it matched for my first 3 brews with it so I stopped taking hydrometer readings and starting just going with the refractometer. It also matched up with my TILT, which has a 6 points calibration against my hydrometer. Third, I only do 2.5 gallon batches so having to take a hydrometer reading before and after fermentation wastes a lot of potential beer so a few drops on the refractometer is good enough and accurate enough for me.

what about using a scale before and after fermentation with the same volume? Because densitiy of alcohol is lower than water. It is the same like using hydrometer.

We used to use a Gas Chromatograph with flame ionisation detector, employing a 1M packed column with a PEG20 M Stationary phase and direct injection.

Honestly, hydrometer is fine. If you want a chemistry lab then go for it but a hydrometer will give you good readings. It is definitely important to cool your wort down and warm your beer up when using it though to make sure it's at the correct temp. Especially with very hot wort, you will get wildly inaccurate readings. If you just run you flask under a tap whilst being careful not to get any water in the sample, it will cool very quickly.

I use a refractometer in conjunction with a hydrometer. I find it useful for quick and dirty readings at the beginning and end of the boil to make sure I'm in the ball park and don't need to make changes to stay on track. I definitely don't use my refractometer to get "official" measurements.

why does my proffing hydrometer not measure a thicker alcohol in brandy ? it was thicker than the rum that i used

I should've paid attention in math & science class...

How do buy One

COOL!

how he get the 131.25? what is it?

100% on the refalseometers

I like to test it by drinking a pint and seeing how I feel 5 minutes later.

The first time I home brewed I thought my hydrometer said my lager was 46% alcohol. So maybe I need to pay attention to this vid...

Im drunk after this video

So the Anton Paar stuff is good to 0.5% ABV? Say I brew a 5% ABV beer, that's 10% variation, assuming you didn't mean, +/-0.5% ABV which would be 20%... So if that's acceptable accuracy, then how far off is a standard refractometer? I'd be surprised if it were more than 0.5% ABV out.

is there one that dose not need a app just looking for something that is ez to use that dose not need any internet coneted to it why as some times the makers just brick the thing you payed for

I was at a bar yesterday, some guy flagged me down and said he'd buy me a beer. Turns out he was a part of a famous robbery where Im from. Anyway, I had a bottle of vodka and the bartender noticed. Long story short he held on to it and today I was worried it had been watered down. Turns out ice cold vodka just doesnt taste the same. It lit on fire and it was 40%, so I guess he didn't.

What's your opinion on the accuracy of using a TILT for OG and FG?

Curios why you made the first version of this video unlisted now and reuploaded this version? There are good comments in the comments section of the unlisted video.

Alcoholomometerizorator

refractometer = so many corrections

sooooo this was just a commercial for a $400 hydrometer?

Not wrong, just misunderstood... The great thing about using a refractometer after ferment is to compare it to the SG from the hydrometer. There is now a way to calculate abv from the discrepancy due to the difference in density vs refraction of alcohol vs sugar in solution. If you want to measure SG to know when to stop fermenting however, just use a hydrometer and stop faffing about.

I think your disliking of refractometers is hilareous. I do like 'em though. I don't care that much for the alcohol content, and rarely take a reading of the finished beer anyways. The thing just tells me if I'm in the ball park or not. I do recognize sediment makes the readings vary wildly. Which is annoying.

I just brew and drink,😂😂😂😂😂

Why ×131.25

reupload?

Refractometers are rubbish? I did not know this.

Drink With Me

refractometer is a waste of money... hard to be accurate and still have to do math. Meh

couldnt agree more about the refractometer, absolute garbage