Taking an accurate Hydrometer reading

Hi Folks,

New brewer here, I am currently doing 1 gallon batches with BigMouth Bubblers as my fermentation vessels. My question is, can I just put the hydrometer in the fermented wort right in the Bubbler without taking a sample with a tube? Would like to save as much wort as possible since it is small batch brewing while also keeping strict sanitation in mind.

Thanks for any information in advance!

The answer would depend on the actual amount of wert you have.  The hydrometer needs to float and is there is not enough wert the hydrometer will touch the bottom and serve no purpose.  You may have to resort to another measuring method.

It can be done if the fluid level is deep enough, but it is not advisable from a sanitation perspective in my opinion.  I’d just watch the fermentation and give it a few days after the krausen drops and the beer clears.  Otherwise drawing off some to put in a measuring tube with the hydrometer is the preferred approach.  Small batch brewing has its obstacles, such as this, but it will turn out fine for you, I am sure.

Cheers!

Like most experienced brewers, I only take original and final gravity readings.  I never take readings while a batch is fermenting.  It is easy to tell when a batch is done.  The beer will start to clear from the top.

Thanks everyone!

Totally agree with Saccharomyces - just take a reading before and after No need to check during the middle of fermentation usually unless you are trying to spund the beer. Also, for one gallon batches you might consider a refractometer for taking reading since it only uses a drop of wort. You do have to make the correction for the final gravity. I’ve seen them as cheap as $15 before. Worth the money.

I brew smaller batches myself. I use a refractometer to take a reading at the end of the mash and the end of the boil, and that’s it. I don’t bother taking a final gravity reading unless I have a specific reason (i.e., I need to troubleshoot something, or I’m dialing in a new recipe). I can’t taste the difference between 1.010 and 1.012 for FG, nor do I care whether my ABV is 5.1% or 5.3%.

I agree that this is fine for EXPERIENCED brewers. However, for those who are still learning, I think it is valuable to take readings so you learn how fermentation progresses. After awhile you will know, based on length and vigor of fermentation and by the appearance of the surface, how far along the beer is. Then you don’t need the measurements, but to get to that level of experience it helps (or at least it helped me) to have frequent measurements that you can correlate with the beer behavior and appearance.

I am another one who generally only measures gravity at end of mash and end of boil to make sure I am around my final OG. I do take a FG reading sometimes when I am using a new yeast or unusual grain bill.
I wonder if there really is a sanitation issue using a hydrometer in a fermenter though. I have done it before and actually think that cleaning and sanitizing a hydrometer is easier and more effective than doing the same to a wine thief or any other method for removing wort. Obviously you want to be super careful not to break the hydrometer on the way in or out.

Good point about not really needing an FG measurement if the beer tastes right.

I take FG measurements in the fermenter every batch. I sanitize the hydrometer first.

Recently I was really vexed by high FG measurements several batches in a row. I couldn’t figure out what was wrong with my process. I also couldn’t figure out why the beers all tasted just fine despite high FG readings. In the end my hydrometer was the problem not my process or beer.

Of course another option is to invest in a Tilt hydrometer (or a smiler product).  That way you can monitor gravity readings continuously without needing to draw a sample from your small batch.  I realize there is some controversy about the accuracy of these immersion, Bluetooth reporting hydrometers, but they’re accurate enough for me!

+1.  It gives you good start, progress, and completion. No guessing when it’s finished. The readings may be +/- but there’s no question on activity.

We like using the Refractometer. As stated, you only need 1.247 drops. So little waste.
And there are a number of online conversion calculators to employ to get your adjusted gravity readings when alcohol is present. Surprisingly, these calculators are quite accurate.

I prefer taking a 12 oz. FG reading,  putting it in a 20 oz. PET bottle.  I hit it with 30 psi, put it in the freezer for 45 min. and I have a cold, carbed sample to try.

I honestly don’t think it’s worth it to take readings on a 1 gallon batch. You’re lucky to get more than 3 pints out of a batch size like that. Let it ride for 2 weeks, then package it.

If you absolutely must know, you could get a Tilt hydrometer. It won’t help you make better beer, but it can give you some peace of mind knowing what’s going on with your beer.

For a new brewer who bottles, taking two FG readings 2 - 3 days apart is a good safety measure. If gravity has dropped, don’t bottle. I brewed 162 batches with no slow fermentations. But batch #163 took 29 days. Then batches 169 and 171 were even slower. (All three of these were with Mangrove Jack’s yeast, which I have stopped using.) I only knew they were slow because I took consecutive readings, and the SG dropped slightly. I kept checking until the gravity was stable. If I hadn’t, I feel sure there would have been bottle bombs.

Just learned that you do not have to read the hydrometer correctly, as long as you are consistent in your reading method.
This pertains to checking for ABV.

My readings were off, by 2 points. But the margin was the same over the correct readings vs the incorrect readings. So the ABV numbers were correct with both readings.