The 3 week fermenting rule -- should I?

[billpaustin]

My plan is to let the fermenting beer sit in the glass carboy, which I use as a primary, for 3 weeks. After that, you can bottle or keg, without having to worry if fermentation is done, right?

Are there cases where waiting 3 weeks doesn't help you? I will brew almost all wheat beers, and don't care much about cloudiness. How soon can I reliably bottle or keg?

 

[Nagorg]

I pretty much always bottle at 3 weeks.

 

[Polboy]

no you shouldnt, it may be done in 5 days but it may take 6+ weeks to finish fermenting (data from my own experience), it is safe to bottle when final gravity is stable for few days (lets say 3-5)

 

[YeastHerder]

My plain german-style wheats are done in about 10 days (stable FG for 2-3 days at that point), I bottle condition and those can be carbed up and ready in as little as 8 days - maybe because there is so much yeast still in suspension. I wouldn't bother checking any other style at that short of time though.

 

[unionrdr]

On average,my ales take about 3 weeks to reach Fg & settle out clear or slightly misty. But I do make good use of my hydrometer. That's the only way to know for sure.

 

[Yooper]

A well made beer shouldn't ever take three weeks to finish. The fermentation should be done in about 5-7 days. Then, the "clean up" period happens over the next 24 hours or so, so leaving the beer for about 10 days generally assures that fermentation is finished as is the "clean up" period.

After that the beer will start to clear. A highly flocculant yeast will usually mean a very clear beer by day 10 or so, but with less flocculant yeast it can take longer to clear.

I normally leave beer in the fermenter for 14 days or so.

 

[rklinck]

I agree with Yooper. (Note to self, that is always a good thing to say.)

Most of my normal gravity beers hit FG within a week. I normally leave them in fermenters for 3 weeks because I have a good pipeline so there is no need to rush. If you want/need to packages sooner, you definitely can. Earlier this week, I kegged a blonde ale 10 days after brewing it. The OG was 1.042 and it was down to 1.009 (right where I expected it), it was already clearing, and it tastes good. I only rushed this one because I have people coming for a BBQ this weekend and don't want to risk running out of beer.

There is actually a sticky in another one of the forums by Yuri_Rage about how you can easily be drinking beers 2 weeks after brewing them (assuming you keg).

If you are bottling, I would be more cautious to take gravity readings a few days apart to make sure the beer is finished fermenting (to avoid overcarbing in bottles). In a keg, the worst that will happen is that you have a little bit of residual sugar that could have been fermented.

 

[billl]

"All" is a pretty dangerous word for life in general and brewing specifically. There are pretty much always exceptions. eg I think it is impossible to turn around any of the traditional sour styles in a week. There are also some belgian strains that tend to take their own sweet time with those last few points.

 

[rklinck]

"All" is a pretty dangerous word for life in general and brewing specifically. There are pretty much always exceptions. eg I think it is impossible to turn around any of the traditional sour styles in a week. There are also some belgian strains that tend to take their own sweet time with those last few points.

I agree, and hope that no one understood me to be saying that "all" beers will be ready within 10 days. My point was simply that for most normal gravity ales using the most common strains of yeast, the beer can be packages in far less than 3 weeks.

 

[unionrdr]

If you've pitched a lot of yeast,yes. At least,from what I've read on here from Mr malty & all. They give a proper yeast pitch that seemed to me to be at least double what comes in a kit,packet,or vial/smack pack.

 

[Schol-R-LEA]

The three weeks rule is only a rule of thumb, and a largely obsolete one at that; in the past, when good ingredients, sanitizers, and information were hard to come by, three weeks gave you plenty of time for fermentation to complete and to let off-flavors dissipate. Improved ingredients, equipment, and techniques should obviate the need for that today. In any case, it is better to use the hydrometer and bottle after the gravity has been stable for three to five days, rather than following a time schedule. There are several variables involved, and not all beers finish at the same rate; three weeks is generally the longest a moderate gravity beer will take, hence the rule of thumb.

While in the past I have followed the old rule - one week in the primary, then rack to the bright tank for two more weeks before bottling - it really isn't necessary with any ales of moderate gravity. Higher gravity ales need more aging in general, but again, you want to follow what the hydrometer says, not a time schedule.

(Lagers are a different story altogether, and inadvisable unless you have suitable temperature control and are willing to wait at least a month for cold aging.)

 

[rklinck]

If you've pitched a lot of yeast,yes. At least,from what I've read on here from Mr malty & all. They give a proper yeast pitch that seemed to me to be at least double what comes in a kit,packet,or vial/smack pack.

I should comment that I am a dry yeast guy. I use US-05 or S-04 for most of my brews, and I pitch one packet. I think part of Yooper's comment about a "well made beer" would include an assumption of proper pitching rate. If you are using liquid yeast, this will require a starter.

 

[BetterSense]

Fermentation is usually over in a week, which you can verify by hydrometer. However, determining the true end of fermentation is more work than just letting it sit for 3+ weeks. Leaving it the fermenter longer sometimes has a positive effect on the beer, and it tends to make it easier to rack because the yeast settles out better.

I have bottled beers in as little as 4 days, but I generally follow the 3-week rule, because 1)It's simply easier and I'm lazy 2)there is no downside, unless you are in a hurry. If you are in a hurry, you need to manage your pipeline better.

 

[unionrdr]

I should comment that I am a dry yeast guy. I use US-05 or S-04 for most of my brews, and I pitch one packet. I think part of Yooper's comment about a "well made beer" would include an assumption of proper pitching rate. If you are using liquid yeast, this will require a starter.

Yeah,that's why I mentioned yeast calculators. I generally use one packet for up to medium gravity ales. Starters for liquid yeast generally. So with the "proper pitch rate calculators" I've seen that beers ferment out quicker. But cost more for making big starters,or pitching more than one packet.
Like with the Burton ale I brewed. I rehydrated 4/7g ale yeast packets for that one.