Help Me Use My Hydrometer!

I just realized that I've omitted using my Hydrometer!!!

SO I don't have an official OG measure. So can everyone pitch in and give me/us a 101?

When should I use it? At start? at each transfer? at bottling? when drinking?

How do I use it?? Pull out some fermenting beer and measure?

Thanks for the help! Amazing that the kit I ordered did not come with Hydrometer instructions. Your help appreciated!

-C

Most important time to use the hydrometer is to check if your beer is finished fermenting and ready for bottling - this is usually a week or 2 from the start of fermentation. Leaving it longer is not a problem but bottling before fermentation is finished can be a big problem, so it's important to check for a consistant reading for 2 or 3 days in a row.

To measure, you need to take a sample from your fermenter (observing proper sanitation practices) and place the sample into the measuring tube that came with your hydrometer, stick the hydrometer in and take a reading. Do not return the sample to the fermenter.

Here's how to read a hydrometer: http://www.stevenson-reeves.co.uk/howto.htm

I try to take an initial (OG) just before adding the yeast. Then checking for fermentation completion (usually just prior to bottling). This way I can figure alcohol content (ABV). Aidan has the correct method to check. I'm too lazy and figure nothing bad will drop into my beer (I know, misguided.) and check with a sanitized hydrometer. Hydro's are deceptively more fragile than they look. Check the broken hydrometer post.

I'll add a couple of things here.

Check the temp of the sample. Hydrometers are calibrated to be accurate at a certain temperature. There are conversion tables so that if you read your hydrometer with the sample above or below the calibrated temperature, you can convert the reading at that temperature to the correct calibrated reading. That said, the reading will always be more accurate at the correct temperature.

In general, take the reading from the bottom of the meniscus as shown in the link above. That said, not ALL hydrometers are calibrated this way. Some are calibrated to be read from the top of the meniscus. They will usually indicate one way or the other but if there is no indication read from the bottom.

All of the above advice is good but to add to that, consistency is key. If you're reading your hydrometer at 74º for SG, then read at 74º for FG. The accuracy of the reading at the homebrew level and for homebrewers is fairly irrelevant. You're looking for some indication of a starting gravity and a solid indication of end of fermentation. With those two readings you can calculate abv but it's not like you need to be within two decimal places for a lab or anything. Will you be able to tell the difference between a beer that finished at 1.010 vs 1.011? Not likely.

Just go with consistency in your readings.

Suthrn said:

Mine usually ends up in my mouth!!! Best place I've found to dump the stuff.

Click to expand...

Truth.

Suthrn said:

Mine usually ends up in my mouth!!! Best place I've found to dump the stuff.

Click to expand...

Same here. It's good to get a feel for how your brew is progressing. But don't get alarmed if it doesnt taste so good at this stage. The OG samples especially can be hard to swallow.