Checking FG

[Chris5899]

Is there any reason at all to check FG before allowing at least 10 days for fermentation? My first brew ever has been fermenting for 5 days, airlock bubbled from day 2-3 then stopped. It's an ipa, OG was .064. Used wlp001 in a starter. After reading many threads, whenever someone is worried about FG, the advice is for them to leave it alone for another week....its hard to not mess with it, but if it is done fermenting, its going to sit and condition for a while anyway.

 

[BrewerE]

Not really, every time you open the lid, you risk contamination.

Leave it for 2 weeks, take a reading, wait 2 or 3 days and take another, if they are the same get ready to bottle.

 

[usfmikeb]

Yep, better to let the yeasties alone to do their work.

 

[LAbrewer]

I like to check when fermentation is first finishing up. Then I check again in a few days. So usually 3-5 days and again at 7 days. I just like seeing the changes or lack of and making sure there isn't a break out of something funky. No real reason though.

One reason you may want to check early is to determine if it's time to toss in the hops for the DH. Once at FG it's time imo. So if you go 5 days to FG, then DH for 7 days, you can crash for 2 and condition/ prime/ gas up after 14.

 

[PerryS]

Is there any reason at all to check FG before allowing at least 10 days for fermentation? My first brew ever has been fermenting for 5 days, airlock bubbled from day 2-3 then stopped. It's an ipa, OG was .064. Used wlp001 in a starter. After reading many threads, whenever someone is worried about FG, the advice is for them to leave it alone for another week....its hard to not mess with it, but if it is done fermenting, its going to sit and condition for a while anyway.

It's hard to resist messing with the yeast. We're on internet time while they're on geological time.

Fermentation speed depends quite a bit on the yeast strain, temperature, and fermentable sugars. I measure the time between bubbles in the airlock. There is a geometric spike as the yeast colonize the wort, then a somewhat logarithmic decay as the yeast chew through the available sugars. I don't check SG until there is at least 60 seconds between bubbles.

If you're using a plastic pail, the lid may be leaking CO2. If your sense of smell is finely tuned, you may smell fermentation around the lid seam. Give the pail a swirl (or a slosh) to cover the seam in sticky wort. Be careful - the wort is loaded with CO2, so you could also get wort blowing through the airlock.