How often do you check gravity?

Discussion in 'Homebrewing' started by cates1tg, Jan 12, 2013.

  1. cates1tg

    cates1tg Savant (265) Michigan Jul 18, 2010

    I've looked through the threads for a bit and didn't find anything that really answered my question. My first batch has been in the primary for a week now and was just curious when and how often to check its gravity.
  2. koopa

    koopa Champion (835) New Jersey Apr 20, 2008

    I've got comfortable enough in my process and consistent enough in my results that I'm usually lazy now and only check the gravities at these times....

    Prior to Kegging

    Now if I was using a yeast strain I'm not overly familiar with or if I have any concerns about the style I'm brewing stalling, then perhaps I'd also take a gravity reading 4-5 days into primary fermentation but that's about it.

    NOTE: Provided your yeast is healthy and you pitched the right amount, a vast majority (80-85% typically) of your overall fermentation will happen in the first 2-4 days of primary. The rest of the time in primary is more about getting the last 15-20% of attenuation and allowing the yeast to clear up some off flavors (bi-products of fermentation). I usually leave my beers in primary for 10 - 28 days depending on the style. Wheat beers and session beers in the 10-14 day range, high gravity beers in the 21-28 day range, but everything else in the 14-21 day range.
  3. AlCaponeJunior

    AlCaponeJunior Champion (810) Texas May 21, 2010

    Basically "what koopa said"

    I generally only check before fermentation begins, then again on bottling day. If it's where I think it should be, I bottle. If for some reason it was more than a few points off of expectations, I might leave it a few days and check it again, just to make sure it didn't drop. Theoretically you should have two readings several days apart that should match. Practically, if you're pretty familiar with your system and you're familiar with the styles and gravities of the beers you're brewing, then you can probably get away with just one on bottling/kegging day.

    If you have any doubts, take more than one reading and make sure they match! I will still do this if using unfamiliar yeast, brewing a new style, or using a new process. Mostly I've been brewing the same basic beers tho.
  4. I take gravity readings twice. Once immediately before pitching the yeast then, three weeks later right before I keg. Big beers may go longer, small beers shorter. Since fermentation is done after only a few days, the only reason I check it is for my records.
  5. i check before i pitch yeast, and then once again after it looks done. i'll usually leave it a few days after it gets into finishing range and continually check it then just to make sure the yeast is done cleaning up, since taking it off the yeast too early is not really a solvable problem.
  6. FATC1TY

    FATC1TY Moderator (910) Georgia Feb 12, 2012 Staff Member Verified Subscriber

    I used to check it every week.

    Now I know it's fine, and I'm lazy, so like someone said earlier. I check it pre boil, post boil, and then whenever I know it's probably got a good chance of being done, by the time I go to keg it. I'll check it then, only to check to see where I finished out at, and the ABV.
  7. Is there any concern with opening the lid to get a sample if using a bucket to ferment? I kind of wish my pail had maybe a small opening that I can stick my thief into without having to take off the entire lid.

    My first batch had fermentation stop early at 1.020. I opened it a couple times to take readings to make sure it was not going to change and both times I was sort of thinking about how I was potentially exposing it to oxygen. I realize there should be a layer of CO2 in there so maybe opening it long enough to take a sample isn't a big deal.
  8. mugs1789

    mugs1789 Savant (265) Maryland Dec 6, 2005

    Only once, in the primary before fermentation.
  9. you could probably cut a hole and then plug it up when you're not taking gravity readings. i don't think it's necessary as long as you're not splashing it around or anything, but if it lets you sleep at night...
  10. pweis909

    pweis909 Advocate (740) Wisconsin Aug 13, 2005 Verified

    1. I check preboil so I have a sense for what the OG will be. If it looks like I will be off, I can adjust in a few different ways: add DME, alter the total boiling time (and therefore the boil off), or add some water to the boil.

    2. Post boil. This is OG.

    3. After a few days of fermentation to evaluate whether I need to ramp temp for a diacetyl rest (generally just a lager thing, but I wouldn't hesitate to do a D-rest with an ale if it seemed like it would help).

    4. When I think I hit terminal gravity, probably between day 10 and 14. If I like what I taste and the gravity seems to be where it should be, I'll let it sit for about a week (just to be sure the yeast had time to do what they need to do and settle out some). Then I may cool it, dry hop it, prime and bottle, or keg, depending on various considerations. If I don't like the taste or the gravity seems high, I'll give it more time, possibly at warmer temps (as per diacetyl rest), and taste in another week.

    Edit: At 3 and 4, I am tasting the beer to evlauate whether I need to make any changes. At 2, I am tasting the cooled wort, mostly out of ceremony. I toast to the brew day with wort, and then have a homebrew.
  11. Pretty much never. I'm comfortable enough with my system to know where things will start and finish.
    inchrisin likes this.
  12. inchrisin

    inchrisin Savant (470) Indiana Sep 25, 2008

    Ha, never. :)
  13. rocdoc1

    rocdoc1 Savant (425) New Mexico Jan 13, 2006

    I check with my refractometer at the end of the boil, then 2 weeks later I take a hydrometer sample.
  14. rocdoc1

    rocdoc1 Savant (425) New Mexico Jan 13, 2006

    You can drill a bigger hole in the lid and then just get a bigger stopper for your airlock. But even better is to install a plastic spigot an inch above the bottom of the bucket. I've used buckets for 20 years, every one has a spigot and I never had a single infected batch
    JimSmetana likes this.
  15. Ricelikesbeer

    Ricelikesbeer Savant (370) Colorado Nov 29, 2006

    If you are patient, you can check your gravity twice, which is more than sufficient. Check it right before you pitch your yeast. (be sure to account for any temperature variation, since your hydrometer is most likely calibrated for 70 degrees.) And then check it once its done.

    I normally wait until my airlock stops bubbling and all of the yeast has settled, then I give it another week or so to sit on the yeast and let some off flavors clean up, and then I check my gravity right before I bottle or keg.
  16. Ilanko

    Ilanko Aficionado (245) New York Aug 3, 2012

    First reading before pitcing the yeast, second reading after 10 days then all must every day, depending on the beer type and the expected(calculated) final gravity.
    if the last three reading measure the same, it's time to bottle or keg.
  17. VikeMan

    VikeMan Champion (845) Pennsylvania Jul 12, 2009 Verified

    Do you think that taking a reading every day (to see three identical readings in a row) will tell you anything that you wouldn't find out by taking two readings 2-3 days apart?
  18. Ilanko

    Ilanko Aficionado (245) New York Aug 3, 2012

    I guess you right, on my side i love to smell my beer and give it close attention.
  19. rocdoc1

    rocdoc1 Savant (425) New Mexico Jan 13, 2006

    If your fermentation has stalled, you'll get the same readings for several days, but that won't mean your beer is fully fermented. I've had beers get to 90% of their expected FG and go on vacation for a week. I may have to raise the temp a few degrees or rouse the yeast to get things going again.
    I's important to know the realistic FG target you're looking for and be able to reach it, and that is hard for a beginner to do. Extract kits will list FG as 1.014, but with all the dark extracts 1.020 may be more realistic.