Measuring Gravity in One Gallon Batches

[torilen]

Okay....this is for anyone who brews gallon batches, or something even remotely close.
(I actually brew 1-1/2 gallon batches now, typically)

I have never actually taken any readings for OG or SG or anything like that, simply
because I didn't want to waste any of what little bit I was actually brewing.

Does anyone have any suggestions on how I can start doing this without losing
any of the brew? I know it can be done if sanitation is "spotless", but I find that
to be taking quite a chance.

As a note - I use Brewer's Friend beer recipe calculator to estimate my ABV. I
usually take what the calculator gives me and figure on between 1/2% to a full %
lower. If the brew ends up close to the estimate, or over, then all the better.

I would really like to start taking accurate notes on gravity and ABV, though. I've been
brewing beer for I guess about a year now, and I figure it is about time to start.

Thanks

 

[torilen]

Never mind - I just found a thread with almost the exact same topic.

An admin can feel free to delete this if you wish.

 

[grampamark]

I know it's not good form to answer a question with a question but-How is dropping a sanitized hydrometer in your fermenter any different from me using a sanitized wine thief to pull a sample out of my fermenter?

As long as your fermenter has a wide enough mouth to make it easy to get the hydrometer in and back out, and you pay reasonable attention to cleanliness and sanitation, you ahouldn't have any problems.

Mark

 

[Brownalemikie]

You don't have to fill the test tube with beer. I simply check OG right in my brew pot after the cool-down (before siphoning into carboy).

Then I check FG in my bottling bucket right before bottling (after 3 weeks in fermenter). Just make sure you sanitize the hydrometer.

 

[balrog]

You can get a good indication using a refractometer. Certainly for OG. Once there's alcohol however, the refractometer is not the perfect tool to use. It can be used, there are a couple of different conversion methods out there, and it will certainly give a good idea of FG, certainly of whether SG is still dropping, but it's not perfect.

 

[Miraculix]

Right in the fermenter is a bad idea as dissolved co2 will falsify the result.

If it is just about whether or not fermentation has finished, I would simply use a refractometer. You cannot really rely on the exact value, but if the value doesn't change any more, it is a sign for finished fermentation as good as a non changing hydrometer measurement.

 

[SanPancho]

At one-ish gallon size losing what you take out to sample sucks, especially if you measure more than once. Yes, it can go back into fermenters, but you’re exposing alot of oxygen to beer.

Unless the other thread has different solutions i think its a choice between hydrometer size or going refractometer. They make small 6inch hydrometer, you need half the sample size of a normal 10-12 incher. Cole parmer sells them for sure. Or just set up to do refractomter correction. Those were the two solutions i came up with.

Let us know what you decide to do.

 

[torilen]

Thanks all. I'll probably look into getting a refractometer. That's what a lot of responses on the other thread said.

Of course, there were several comments that went along the lines of: Who really cares...you're making it for you and your friends...go with an estimate from a calculator and don't sweat the small stuff.

Honestly, I'd like to "not sweat the small stuff"...but I really would like to up my game in brewing
a bit. As I said, I've been brewing beer for about a year. I've been doing ginger beer and wine and cider for maybe two years...two and a half years...something like that. It's time I learn more.

So, yeah...refractometer it is, I believe. And luckily, I have money from birthday and Christmas.

 

[Miraculix]

A decent China one costs around 10 pounds in the UK, just a bit more than a hydrometer.

BTW. I went the same route, ginger beer, wine and now beer

... But will also do some wine again soon.

 

[myelo]

Right in the fermenter is a bad idea as dissolved co2 will falsify the result.

Wouldn't the same apply if you remove the beer from the fermenter and put it in a hydrometer tube to measure? Because that's what I do. Should I be doing something first to get rid of the C02?

 

[Miraculix]

Wouldn't the same apply if you remove the beer from the fermenter and put it in a hydrometer tube to measure? Because that's what I do. Should I be doing something first to get rid of the C02?

Yes, stir or shake well so that there won't be any co2 bubbles which could stick to the hydrometer.

 

[AZCoolerBrewer]

I make 2 gallon batches. I use a standard hydrometer. I reduce waste by filling my fermentors first with the clear wort and then I fill my cylinder with cloudy wort to get my OG. For my FG there’s the last beer that gurgles and only fills half way up. I use that plus what the auto-syphon can’t reach in my bottling bucket to get my FG. I have to subtract my priming sugar from reading. After I get my reading, I bottle and cap that last beer and mark it. I open that one first to confirm that the beer is carbonated. I usually get 18 +1 beers from my 2 one gallon fermentors

 

[balrog]

Wouldn't the same apply if you remove the beer from the fermenter and put it in a hydrometer tube to measure? Because that's what I do. Should I be doing something first to get rid of the C02?

You only need to worry if CO2 is coming out of solution (there is some in there) and attaching to the hydrometer to float it up and give an incorrect reading. I've seen this happen in summer for instance if I fermented at 60° and took hydrometer reading sample, put in hydrometer and started bottling. As the hydrometer sample warmed, CO2 comes out, and teeny tiny little bubbles attached to the hyrdrometer. Just wait until it's temp stable, I stir with my long thermometer to get temp and "degas", then drop in hydrometer and read.