How long can beer sit on the yeast cake before bottling?

[Silver_Is_Money]

How many weeks can a newly fermented beer (ale or lager) be permitted to sit upon its own yeast cake in the fermenter before it may begin to pick up off-flavors?

 

[Sammy86]

This is a topic of debate...many brewers here leave their beers in primary for 4-6 weeks and haven't seen any ill effects...the real question is how long does it take for your beer to finish fermenting...that depends on your OG and yeast pitching rate

Many have left their beers on the yeast cake for months at a time and haven't had any ill effects

 

[Wogman75]

If I could add on to this question, not so worry about off flavors which might go away the longer it sits but how long before you won't have enough active yeast to bottle carbonate?

 

[kristiismean]

I think it all depends on what kind of beer. I believe it still does effect that taste of your beer.

the Best ESB I made sat on a cake far longer than I wanted it to.

My Friend did a topper clone, and life got in the way. it's the worst beer I have ever tasted.

 

[stella_tigre]

Usually we leave it 3 to 4 weeks, but we kicked a ferment off just before we went on vacation. So it was 6 weeks before it went to the keg. Didn't hurt it at all.

 

[Silver_Is_Money]

I'll be at 4 full weeks in the fermenter tomorrow. And for 3 of those weeks there has been no bubbling activity seen in the airlock. Should I consider this to mean 4 weeks sitting on the yeast cake, or 3?

 

[flars]

I count the number of days for my note taking from the day the yeast was pitched.

 

[Steveruch]

If I could add on to this question, not so worry about off flavors which might go away the longer it sits but how long before you won't have enough active yeast to bottle carbonate?

It takes a really long time for so much yeast to drop out that there isn't enough to carb. I've gone three months at 34f in a pilsner that carbed fine.

 

[IslandLizard]

I'd say 6-8 weeks is about the limit. Yeast autolysis (decaying dead yeast) gives off a burnt rubber, vegemite, marmite, bouillon cubes kinda flavor and aroma. Higher alcohol will kill yeast faster, so 8 weeks maybe too long, but those beers are usually more robust too, hiding off flavors better.

Most beers are done fermenting after 1-2 weeks, leaving them on the yeast cake any longer has no benefit. If you want to add fruit or other fermentables and leave them on the yeast cake for another 4 weeks you may be stretching it. A week of dry hopping after the 2 weeks of fermentation is well within the safe period. Cold crashing is outside this safe period because of the very low, near freezing temperatures, slowing down or stalling cell death and decay reactions.

Because of this safe period, secondaries are generally not needed, or even recommended as they can (and will) create problems if not done correctly. Racking to secondaries is actually quite an advanced technique, where one tries to limit the amount of oxygen exposure and uptake. Not always an easy feat for homebrewers, given the small volumes we deal with.

For long term aging, long secondary fermentations, sours, etc. secondaries absolutely have a valid use. Just not for the majority of everyday, run of the mill brews.

 

[mwill07]

If I could add on to this question, not so worry about off flavors which might go away the longer it sits but how long before you won't have enough active yeast to bottle carbonate?

last year I made an old ale. I racked it to secondary after 2 weeks on the cake and didn't get around to bottling it for almost 11 months.

After I finally got around to bottling it, I simply used a cup of priming sugar in the bottling bucket and bottled like normal. Two weeks later - it carbed up fine.

I was amazed that the yeast in suspension stayed viable that long.