How do you measure gravity for beer?

Do you just take a sample of the beer before and after fermentation and drop a hydrometer in there?

i sanitize the hydrometer, and drop it in and take a reading, then do the same after i feel ferm is over

lumpher said:

i sanitize the hydrometer, and drop it in and take a reading, then do the same after i feel ferm is over

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Thanks. Do you do the readings in a separate container?

I take a sample using a sanitized turkey baster and put it in my hydrometer cylinder. I record the OG before pitching the yeast and start looking for the correct FG by watching the gravity and waiting for it to stabilize after an appropriate time in the fermentor. I usually dont bother the fermento for at least 2 weeks before I start looking for the FG. Once you get a stable reading over a few days tour done fermenting and it's time to keg or bottle. Hope this helps point you in the right direction.
Bob

Original gravity from wort before adding yeast
Final gravity when fermentation ends
Little bit of math and I have an alcohol content

Nightshade said:

Original gravity from wort before adding yeast
Final gravity when fermentation ends
Little bit of math and I have an alcohol content

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Screw math, there are plenty of apps, web and phone/tablet based that do the work for you

Ramitt said:

Screw mat, there are plenty of apps, web and phone/tablet based that do the work for you

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How do those work?

Try to make sure there are no bubbles on the surface to hold up the hydrometer. I try to remove them with a straw then spin the hydrometer to get a good reading.

Go ahead and buy Beer Smith or some other brewing software. They're only twenty bucks or so and your going to need one sooner or later. Otherwise, How to Brew has all the formulas.

http://www.howtobrew.com/intro.html

Also consider getting a "wine" thief that lets you insert the hydrometer directly in to the thief. No, it's not the most advanced piece of equipment, but when used with a thermometer (or thermopen type) it should suffice for providing accurate readings.

I also recommend brewsmith. You'd be surprised at how much temperatures can effect the actual gravity readings. For example: At 100 degrees my hydrometer reads 1.045, but after temperature correction using beersmith's calculations I would actually have an OG of 1.051. The reason I take hot gravity readings is for preboil gravity readings and I can take a gravity reading anytime to get an idea of what my OG is. The other method is just wait until the wort is as close to 60 degrees as possible and take the reading.

Han_Solo said:

How do those work?

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Here is a quick one I googled up. You just enter OG and FG and get ABV
http://www.rooftopbrew.net/abv.php

I started just leaving the hydrometer in the fermenting beer - less to sanitize and I can take a readiing by just cracking the lid of the bucket and looking. I have a wine theif and that works great too but this way is easier and I don't have sanitize as often.

I would not recommend leaving the hydrometer in the wort as it ferments. Dried krausen will end up on the hydrometer and that will throw off your readings.

Get a wine thief, a hydrometer and a hydrometer testing tube. Sanitize the wine thief with a sanitizing solution and sanitize the hydrometer testing tube as well (since the wine thief bumps up against the testing tube sometimes). Draw a sample of the beer with the thief and deposit it into the testing tube. Repeat as necessary until you get enough beer in the tube to the level of about an inch below the top. Close up the fermentor. Take the testing tube and put it over a sink or a bucket and drop the hydrometer in. You'll likely get some spillover due to the hydrometer displacement, but this is wanted, since it will help clear out any foam at the top of the beer. Spin the hydrometer to displace any bubbles that may be caught under or on the hydrometer. If foam still persists at the top, then just blow it off. Be sure to take your reading at the meniscus of the liquid level, not at the very top of the liquid.

Take a sip of the sample to see how the beer is coming along. Don't put the sample back into the fermentor.

I only take mine after fermentation. I have a set efficiency for my setup and I just assume I hit it. I ain't going pro anytime soon so if a Witbier is off from 1.045 to 1.055 and I don't know, it doesn't really matter to me. I do care a lot about FG though. I think that's where you can really taste some flavor differences. Not that I can really do anything about it, but I like to take them then.

I started using Brewballs a few months ago, and have been pretty happy with them. You get a pretty good idea of how far the fermentation has progressed. They're easy to use, although can be hard to see if there's a big krausen.

l3asturd said:

Also consider getting a "wine" thief that lets you insert the hydrometer directly in to the thief. No, it's not the most advanced piece of equipment, but when used with a thermometer (or thermopen type) it should suffice for providing accurate readings.

I also recommend brewsmith. You'd be surprised at how much temperatures can effect the actual gravity readings. For example: At 100 degrees my hydrometer reads 1.045, but after temperature correction using beersmith's calculations I would actually have an OG of 1.051. The reason I take hot gravity readings is for preboil gravity readings and I can take a gravity reading anytime to get an idea of what my OG is. The other method is just wait until the wort is as close to 60 degrees as possible and take the reading.

Click to expand...

Googling "hydrometer temperature adjustment" will accomplish the same thing, for those who are cheap.

FarmerTed said:

I started using Brewballs a few months ago, and have been pretty happy with them. You get a pretty good idea of how far the fermentation has progressed. They're easy to use, although can be hard to see if there's a big krausen.

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Or if you use a bucket

I use a refractometer before pitching, and hydrometer 3 weeks later when I bottle or keg.

And then rooftop brew calculator to get the ABV.