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Hydrometer reading during fermentation

Discussion in 'Homebrewing' started by jtdolla911, Mar 21, 2013.

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  1. jtdolla911

    jtdolla911 Initiate (0) Nov 18, 2011 Massachusetts
    Beer Trader

    I've only brewed 3 batches up until this point. As of now, I have not taken a hydrometer reading during fermentation. Only because I don't want to jump into it and end up compromising the beer in any way. I have a 5 gal carboy with stopper and airlock/blow off tube. Do I remove that set up in order to fit the wine thief in and get the reading? And how long after fermentation starts should I do it? So far, I've just kept my batches in primary for 3-4 weeks before bottling, but I've only done a Belgian Golden and Belgian Pale ales with a Tripel in primary right now going on two weeks.

    Any help is appreciated.

    I bottled my BPA tonight so this information will only benefit the tripel and future brews
  2. TBCHopscotch032

    TBCHopscotch032 Initiate (97) Feb 6, 2012 Florida
    Beer Trader

    I personally only get a beginning and ending gravity reading but a lot of people I have talked to and seen post on here do this a lot. Quite a few people will take several readings and when the gravity stays the same for a few days that is when they know it is done fermenting and ready to transfer to a secondary fermentor. Just make sure you sanitize your theif and minnimize exposure to the air. You will need to remove your blowoff tube/ air lock. I might even suggest sanitizing a second one and use that instead of putting the old one back in.

    As far as how long after fermentation starts, and this is purely an educated guess. I would say when there is little to no krausen left. Im sure people will add to this though.
  3. VikeMan

    VikeMan Meyvn (1,344) Jul 12, 2009 Pennsylvania
    Beer Trader

    Yes. Unless probability wave functions in your brewery are non-typical. Just don't forget to sanitize the thief.

    Either wait for activity to slow down or until enough time has passed that you suspect it might be done (in spite of airlock activity). If the reading is near what you had expected for the FG, wait 2-3 days and take another reading. If it hasn't changed, then attenuation is done. That doesn't necessarily mean it's time to package your beer, because you may want to give the yeast more time to clean up their byproducts. Tasting your gravity samples can help you decide that.
  4. jtdolla911

    jtdolla911 Initiate (0) Nov 18, 2011 Massachusetts
    Beer Trader

    Thanks for the advice. It seemed like a process that was too easy to be true, so i just wanted clarification before moving ahead.
  5. leedorham

    leedorham Crusader (701) Apr 27, 2006 Washington

    fwiw I rarely take a reading during active fermentation. You'll learn to get comfortable just letting the beer do its thing and you'll know when it's done. The only reason I check F.G. these days is to see what the attentuation ended up at.
  6. palmdalethriller

    palmdalethriller Initiate (0) Dec 26, 2007 California

    This is all very sound advice. Tasting gravity samples is key to understanding how your beer is coming along
  7. palmdalethriller

    palmdalethriller Initiate (0) Dec 26, 2007 California

    I am the same way, but I understand that others are more meticulous. For me, brewing is a relaxing hobby, but all the little things that go along with it can become chores if you let them. If you want to make professional-quality beer, then meticulous notes and scientific procedures are the way to go. If you're just having some fun on the weekends, then don't fret so much.
  8. mikehartigan

    mikehartigan Aspirant (297) Apr 9, 2007 Illinois

    As many others do, I simply ignore it for 2-3 weeks. By then, it's virtually guaranteed to be done fermenting and ready to be kegged, which happens whenever I can find 15 minutes to spare. :wink: I check the gravity at kegging time so I can do the necessary calculations for attenuation, ABV, etc. and wrap up the technical portion of my notes. Obviously, lagers, high gravity, and other unique beers are given a bit more time and scrutiny, so this 'one size fits all' fermentation schedule is not universally applied.
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