I'm posting this in here so it's part of the "canon" of info...
It's from another thread...
User name protected said:
I read the sticky at the top of the forum page but it contains extremely contradictory advise. Several posts say fermentation needs to start BEFORE 12 hours (that is, there should be visible sighs!) while several other posts says no, no, WAIT 72 HOURS. WTF?! As a n00b, I am not sure which to believe...
.....
Two things come into play here...How do you define no fermentation happenning? If you are in a bucket and going by airlock activity then you are using a faulty indicator of it...It's NOT a fermentation gauge, airlock bubbling means absolutely nothing, it's just a pressure release valve, something to keep from blowing the lid of the fermentor...
If you are in a carboy then you MAY see a krausen OR you MAY have had a rapid fermentation and the Krauzen fell while you were asleep...
GENERALLY speaking the 72 hour rule of thumb serves several purposes...it takes into account LAG TIME that some yeast DO Need before they start.
It takes into consideration the fact that NO TWO FERMENTATIONS ARE EVER THE SAME....Since we're dealing with living micro-organisms it's important to note this fact....and because that one must learn to realize this, and trust that in most normal circumstances the yeasts ARE FINE, they've been doing it for several thousands of years, and THEY are the experts...
A normal healthy yeast, in a sanitary environment, brewing a normal gravity beer between 60 and 70 degrees (for ale, less for lager) WILL 99% of the time FERMENT....it's not like the old days when yeast came in one strain, in an ugly dried out cake....A lot of the mentions in books and things about stuck fermentations were from back in the bad old days....and someone reads something about it, and usually uses airlock activity as an indication and panics and thinks their fermentation is stuck...and the meme virus continues.
Stuck fermentations do happen (I'm dealing with one now), but they are not as common as the threads here indicate. They are the result of things like high grav worts, temp fluctuations , or less than healthy yeasts or under pitching.)
What we recommend is that if you are nervous, to wait 72 hours and take a hydro reading....
99.9% of the people who start these threads and do that, come back and say... "Oh yeah I panicked for nothing, the beer is fermenting, hehehe."
Like this from today.....
Rev.
Wanted to let you know that everything is o.k. Checked on the primary this morn. There is still no bubbler activity, but when putting my nose to the bucket, there is that distinct aroma. I opened the lid and saw A LOT OF KRAUSEN. So much that I had to resist the temptation to make a beard and mustache out of it. hahahahaha. I'm going to give it 10 days until I check S.G. again.
Thanks
If you have no drop in gravity points, then you pitch a clean dry yeast into the fermentor...just sprinkle it on top, or rehydrate....then you close up and walk away...
Take a read of this for more info...
http://blogs.homebrewtalk.com/Revvy/Think_evaluation_before_action/
A lot of us pitch, walk away from the fermentor and return in a month to bottle trusting that all is well....because 99% of the time it is.