How do you gauge fermentation length?

I generally get my beers off of the primary yeast after 4 days (the house strain I've kept alive since the mid 1980s brings all but my biggest brews very close to FG by then). I rack it to a secondary carboy and leave it be for another week (or longer if I'm busy) to let the remaining suspended yeast do it's cleanup as it finishes up and settles out. I then cold-crash it and after 2-3 days of that, will usually (though not always) dose it with gelatin and rack the resulting bright beer to the keg.
Takes a bit more time, but I learned long ago that the extra time is in the vast majority of cases very beneficial to the beer. And also, by brewing often enough, I always have well conditioned (and in the case of stronger beers, well aged) beer to enjoy and don't need to be in a hurry.

 

I will leave me beers alone for about 2.5 weeks. So if I brew on Sunday, I will pitch and leave it be. (yes, I check a couple times a day the first few to make sure things are going well, no blowoffs and so forth)
So the third Wednesday or Thursday, I'll pop it open to check gravity, then reseal. I will normally plan on bottling over the weekend, so that morning, I'll check gravity again. Presuming it's the same, I'll go ahead and start the process to bottle.
If not, and this has only happened a couple times, I'll reseal again and leave it be for another week or 2, depending on how far the gravity moved in those couple days.
I don't secondary, except for sours / bulk aging or ciders, so I don't worry about that part of it.
Short part: plan for 3 weeks in fermenter, 2 - 3 weeks bottle conditioning.

 

Lots of folks are opining that they consider fermentation to be ‘complete’ (as in ready for bottling/packaging) after a timeframe of several weeks.

If a healthy fermentation has occurred then the beer can be packaged once fermentation has completed (i.e., the beer has reached its final gravity). There is nothing wrong with following a practice such as allocating a timeframe like 2 weeks before packaging a beer and there may indeed be a benefit if there is a need for some ‘clean up’ activity (have the yeast process ‘excess’ acetaldehyde for example) but as long as the fermentation was a healthy fermentation the beer is ready for bottling once the final gravity is reached. This is what commercial breweries do with good effect.

The vast majority of my homebrewed ales have completed fermentation in less than 7 days. Due to the vagaries of life I don’t always bottle at this timeframe but sometimes I do and when I do the beer turns out great.

Cheers!

 

"I learned long ago that the extra time is in the vast majority of cases very beneficial to the beer"

I don't get it...it sounds like only 4 days in primary, a week and a half in secondary, and then usually gelatin? If you are going to let it sit/condition after kegging, what's the rush?

 

You have said something like this before, but it's misleading. The clean-up chores do overlap attenuation. But they don't normally finish until some time after attenuation is finished. It's just the way yeast work, no matter how "healthy" the fermentation was. Every fermentation produces diacetyl. Every fermentation produces acetaldehyde. Every fermentation produces fusel alcohols. Cleanup doesn't necessarily take a long time, but it takes time, and the finish is normally after attenuation finishes.

Put another way, if you could somehow determine the instant that FG is reached, and filter out the yeast at that point, you'd make some pretty bad beer.

 

I do 10-14 days with regular gravity ales, 2-3 weeks for high gravity (>1.080 OG). I bottle condition, so I take 2-3 days and crash the beer in primary (<45F) before bottling to aid in flocculation. I've found less than 10 days in primary to be iffy at best.

The few times I've bottled from primary in less than 10 days, its taken another month of bottle conditioning to help the beer reach maturity. When commenting on commercial brewers' fermentation time, realize that they may do 5-7 day ferments then package, but the package itself often takes 1-2 months after bottling to reach its intended marketplace...plenty of time for the beer to condition and mellow. Interestingly enough, I find the common experience to hold true...i tend to be finishing up drinking a batch about 2-3 months after its bottled, right as it is hitting its peak :/

 

“When commenting on commercial brewers' fermentation time, realize that they may do 5-7 day ferments then package, but the package itself often takes 1-2 months after bottling to reach its intended marketplace...plenty of time for the beer to condition and mellow.”

Just keep in mind that the vast majority of commercial beer is filtered prior to packaging so commercial beers do not condition within the sense that homebrewed bottle conditioned beer conditions. IMO, the commercial beer is ‘done’ from a yeast/fermentation aspect at the 5-7 day mark.

Cheers!

 

Yea... I don't think I can agree with you on this one. Beer without a doubt benefits from sitting on the yeast. Try a side by side you will see especially with a pils.

 

Well, a properly brewed pils is lagered. That is quite different from an ale. Commercial breweries package their ales about 5-7 days after pitching (and filter out the the ale yeast).

Cheers!

 

Don't a lot of commercial brewers ferment at higher temps and under pressure to speed up primary? Fermenting in bunged/spunded vessels is also said to help with cleanup of things like certain esters and fusel alcohols that would typically be produced (and retained) at such temps. It takes a lot of skill to maintain healthy yeast in such conditions, but these folks typically know what they are doing. Perhaps this explains (in part at least) commercial brewers' abilities to have their beers successfully finish up so quickly.

 

Which breweries are those? The breweries I have toured and/or brewed in take longer than that for ales from grain to finished product, either filtered/carbonated/bottled or bottle conditioned.

Also, keep in mind that one reason commercial breweries are able to do everything faster is that they can ferment at higher temps, because their fermenter sizes/configurations suppress fusel/ester formation.

 

Below is something I posted previously on this topic:

“According to white papers authored by Dr. Chris White, Diacetyl peaks during the exponential phase of fermentation and the diacetyl is reduced (absorbed) during the stationary phase. For a typical, healthy ale fermentation the exponential phase occurs during days 1-4 and the stationary phase starts thereafter. If you choose the worst case value of 4 days, then the stationary phase will start at day 4 and over the next few days the diacetyl will be adsorbed.

Mattbk posted: “So, now I'll usually have a mostly complete primary at four days, I'll give 2 days for some conditioning time, and then I'll package”. This is entirely consistent with what is published in Dr. Chris White’s white papers.”

Cheers!

 

I know this is politically incorrect, but I use the bubbles that may or may not be coming out the first week as an indicator

Then I usually let it sit for > ~ 2-3 months... because I am NOT a commercial brewery...I am a homebrewer.

 

That's my "schedule' too. I ferment beer in an insulated plywood box with an AC for temp control and it's a PITA to open so I don't. After 2 weeks I'll check gravity, taste it, and make my decisions from there.
I can't see bubbles but I can hear the thump of the CO2 hitting the growler through the blowoff hose.

 

Mr. Wizard discussed ale fermentation timelines in BYO:

“So, given this information, you want to know if a four-day fermentation period for ales (assumed) is normal and the answer is unequivocally, “Yes!” I think too many descriptions of homebrew fermentations are based on using outdated methods where little packets of yeast were tucked beneath the lids of extract cans and often not used quickly enough.

The quality of yeast, both dried and liquid, is much better these days for a number of reasons — and I think the biggest reason is the strength of the homebrew market and the demand for such products.

Aside from the argument presented above, rapid “normal” beer fermentations generally produce cleaner beer. Many of the off-flavors associated with fermentation, such as extremes with higher alcohols, esters, sulfur compounds, acetaldehyde and diacetyl, are associated with weak fermentations.

On a practical note, we use White Labs WLP001 American Ale for most of our ales at Springfield Brewing Company. Our primary fermentation period for ales with original gravities between 11–14 °Plato usually is complete in three days. There is nothing abnormal with seemingly-short four-day fermentations!”

Cheers!

 

But that reply from Mr. Wizard was in response to a question specifically about using yeast starters when brewing ales, where the questioner experiences fast primary fermentation periods when using a starter vs. just pitching the yeast. I had assumed the OP was asking about a situation in which he was pitching the yeast without a starter. I would hate to mislead the OP by insinuating that his beer is ready for bottling after 3-4 days, esp. if he's not using a starter. Also, WLP 001 is an exceptionally fast finisher -- much, much faster than any other yeast I have ever used -- and not really representative of ale yeast in general (IMO and experience).

 

I would never recommend to a home brewer to package his beer after one week. There is one micro brewer in Michigan that lets his beer sit on the yeast for four weeks. (so I've been told.)

 

The most important messages from what Mr. Wizard published is:

· It is not unusual for a moderate gravity ale to complete fermentation in 4 days.

· At Springfield Brewing their beers complete in 3 days

· “…rapid “normal” beer fermentations generally produce cleaner beer. Many of the off-flavors associated with fermentation, such as extremes with higher alcohols, esters, sulfur compounds, acetaldehyde and diacetyl, are associated with weak fermentations.”

BA mattbk utilizes a fermentation timeframe of 6 days in his homebrewing practice for ales (4 days for fermentation and an ‘extra’ 2 days for conditioning).

As I already posted: “The vast majority of my homebrewed ales have completed fermentation in less than 7 days.” Let me add one more aspect to that quoted sentence to make mention that it applies to moderate-low gravity ales (which is the majority of the ales I homebrew).

It is popular for BAs to concentrate on yeast count (e.g., yeast starters) when discussing fermentation performance. IMO, having a healthy fermentation is more than just that.

IMO, a healthy fermentation occurs when you:

· Pitch a proper amount of yeast

· Properly aerate (oxygenate) the wort prior to pitching the yeast

· Add the proper amount and type of yeast nutrient to the wort

· Ferment within the recommended fermentation temperature range for the given yeast strain

I conduct all of the above in my homebrewing practice and for moderate gravity ales they complete fermentation and are ready to be bottled in less than 7 days.

As I previously discussed, if a healthy fermentation did not occur then there is a benefit for more time in the fermenter (or secondary) prior to packaging the beer.

Cheers!

 

I don't doubt that you are bottling your beers in less than 7 days. But you do recognize that there is still conditioning going on in your bottles while they are sitting at room temperature carbonating, right? I mention this because people talk about things like "primary fermenter for 'X' days and then package" without talking about the kind of packaging and/or the temperatures after packaging.

 

My personal criteria for a beer being ready to package is when final gravity is achieved and there are no perceptible off-flavors/by-products (e.g., no perceptible diacetyl, no perceptible acetaldehyde, etc.). I taste my beer at packaging time to ensure that it is ready. Since I conduct healthy fermentations for my beers, my moderate gravity ales meet all of the aforementioned criteria in less than 7 days.

Cheers!