Can Beer Ferment Too Long
Homebrew beer cannot overferment since fermentation will stop after the yeast has ingested all sugar, which typically takes between 1-3 weeks. Although it can result in bad tastes and raise the risk of infection, keeping beer in the fermenter for several weeks or months after fermentation is finished can also cause these problems.
It is fine to argue about 2-weeks vs. 3-weeks vs. 4-weeks of primary fermentation, but it is absolutely crucial to finish primary fermentation BEFORE bottling the beer (do you bottle your beer?). There is good news, though, because in some cases, when your fermentation has been truly successful and quick, your beers may be ready for bottling after only one week, maybe less. If you allow your beer to rest a few days longer once the fermentation is done, it may come out a lot better. You might discover when you get back home that your beer needs just a bit more yeast to get it going, at which point you have to wait for the yeast to be pitched again, then really begin to ferment.
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It is a common practice to rack the beer into the secondary fermenter, to allow fermentation to continue longer, but without the settled yeast. It is impossible to over-ferment, but beer left on settled yeast too long may develop off-flavors. Dead yeast cells, hops and grains left behind after the boil and active fermentation may contribute off-flavors when left in contact with beer for too long. Byproducts created by the yeast during fermentation are still present in beer, and these are not desirable in terms of flavors.
Another issue with bottling a beer too early after primary fermentation is that there is a lot of yeast that is still in the suspended state. This causes the yeast to re-mix with the beer being bottled (the yeast will have settled to the bottom of the fermenter. It is not correct, however, to remove beer from primary fermentation vessels at this stage, because there are still important processes going on with yeast.
| Storage | Shelf life |
| In refrigerator | Up to 6 months |
| At room temperature | 4-6 months |
Once activity has died down in the primary fermenter, read back over a few days, and when the beer has settled gravity (i.e., it has stopped dropping), you know that the yeast has fermented all the sugars available.
Then you add another 5gallons to 5gallons of the beer after 12-24 hours, and notice the fermentation time has decreased significantly. This is common with large amounts of yeast, where the main fermentation may complete in 48 hours.
Completely 2- to 3-weeks will make sure the fermentation is fully completed, and yeast has had time to clear out any undesirable byproducts produced during fermentation. Generally, your fermentation should not need more than 2 weeks for completion, however, for some beers, it is necessary that you allow them to rest longer as the yeast may be doing some cleaning that may improve the beers. Often, this happens several weeks after you have finished fermenting, and leaves a lot less sediment in favor of long-term beer storage in the fermenter (usually a carboy) before bottling or kegging. When fermenting ales, you should give about two weeks to ferment before moving your beer to kegs or bottles for consumption.
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Keeping the beer in a fermentation vessel for weeks to months after fermentation is completed can lead to an off-flavor and increased chance of contamination. The longer your beer is sitting, the greater the chance that you will get a disease, and the greater chance your beer will have an off-flavor due to bacteria. As mentioned, though, it may be helpful to let your beer sit for a little bit longer, even when you are done fermenting, because this may condition your beer in beneficial ways, potentially giving you better-tasting beer at the end. Whereas giving your beer time to condition in a fermenter means taking some time after bottling to get your beer where you want it to be.
Even once you reach carbonation (say, after two weeks), the beer will continue to condition/mature in the bottle. If this happens during bottling, the beer will be too carbonated, and it will bubble up and fizz out the bottle just like a soda pop. While there is certainly shelf life for the beer, if kept optimally warm in a fermentation vessel, then yeast will continue working the sugars into your beer, breaking down other compounds too.
The result of this in a fermenter is a beer that continues to bubble up until all of the carbohydrates are fermented, leaving you with a beer with zero body and little flavor.
Brewers who are planning on leaving their beers in a fermenter for an extended time are also using secondary fermentation — this is when the beer is separated again from the lees once most of the bubbling has occurred (the yeast has fallen off). If you are using high-quality ingredients and techniques, pure yeast strains with good starters, and do not plan on leaving the beer in the fermenter any longer than necessary, a secondary is not necessary. Many mainstream references suggest moving the beer into the secondary once active fermentation has subsided – this is the individual fermentation vessel.
When using secondary fermentation, there are risks involved, since it is easy for it to contaminate your beer if not done properly. The major issue of using secondary fermentation in homebrewing is that you are taking risks each and every time that you move your beer.
A good rule of thumb is to measure the initial gravity before you pitch your yeast, and then whenever you are likely to transfer the beer, whether it is to a different container, or ultimately, while bottling/kegging. It is recommended to pull a sample of beer from your fermenter and check your brews gravity ten days after yeast is pitched.
As a general rule, one can keep the beer in the primary fermenter for as long as they want. There is no specific maximum amount of time, although a couple minor risks should be considered. Many brewers will simply follow a brewing recipe or instructions in a malt kit, and let their wort ferment for about one week to ten days. Amongst most homebrewing enthusiasts, it is usually considered to be unwise to keep the beer for longer than four weeks either in primary or secondary fermentation. Many brewers let their beer rest for at least two weeks before bottling, however shorter is ideal for hoppy beers and wheat ales, which are intended for consumption soon after they are made. Depending on style, ales may need three-four weeks to rest in secondary fermentation, lagers four-eight weeks, and Belgian ales eight-ten weeks.
Some styles of beer are not meant to be fully dry (in fermentation terms, dry means well-attenuated). Beers can be considered to be over-fermented only if there is an introduction of wild yeast as a contamination.
You may also place undesirable strains on the yeast in the conditioning/secondary stage, if you take your beer off of yeast lees too early. Additional yeast might be able to resurrect an otherwise stagnant fermentation, though just pitching in a fresh packet of yeast might not be enough, particularly if much of the nutrients are exhausted.
How long can I leave my beer to ferment?
Among most homebrewing fan it is by and large viewed as misguided to leave your brew for over about a month in essential or optional maturation. This 4-week point is a wellbeing net to ensure your brew doesn’t oxidate and gets demolished, notwithstanding, there are kinds of lager you can leave for longer.
Can I ferment beer for 3 weeks?
That being said, an overall rule is typically 2-3 weeks for essential maturation followed by a little while or even a very long time of cold molding/lagering in an optional vessel. The entire interaction requires around 2-3 months, contingent upon the style. This article plunges into additional subtleties on ale fermentation.
How do you know your beer is done fermenting?
The only way to know if fermentation has finished is to measure the specific gravity. Ten days after throwing the yeast, take a sample of the fermented beer and measure the gravity. If both readings are the same, fermentation has stopped. Brewing beer typically takes four to six weeks. The majority of the activity occurs on day one, when the wort is prepared.