Slow n' steady or quick n' intense?

[eadavis80]

I was just curious if there is difference in the quality of a beer depending on how long it takes to ferment. For example, if you pitch yeast at X time and have solid airlock activity (1 bubble every second or so) for 2-3 days and then the airlock activity stops, is that better than having a bubble every 3-5 seconds for an entire week? I know airlock activity does not serve as a direct indicator of fermentation, but isn't it safe to assume if the airlock is more active than fermentation is more vigorous? Or, at the end of the day, is all that matters if if your beer reaches its target FG, whether it did it in 5 days or 20 days?

 

[Falcon3]

Not scientific at all.....but my beers have improved since I started having slower fermentations. I started pitching more, healthy yeast, aerating better (which led to a longer lag time), and holding my temps down in the lower range of the yeast, then raising them toward the end of the fermentation. My ferments used to be super intense and over in 2 days. Now it takes me 5-7 to get down to my FG.

Not sure it has anything to do with time of fermenation, as I've improved a lot of other aspects of my process as well.

 

[KepowOb]

As Falcon3 said, I think slow and steady will give you better results. If you have a fermentation that takes off like a rocket and finished within 2 days, I would think that the temperature is too high and that would mean some off flavours.

That said, if you properly aerate your wort, and pitch the right amount of yeast, it might really take off anyway... but I can't think of a beer I've done (that had proper temperature control) that was finished fermenting in 2-3 days.

 

[Yooper]

The speed of fermentation doesn't really matter.

What happens, though, is those fast and explosive fermentations are that way simply because they are way too warm. The warmer it gets, the more active the yeast becomes, and then it gets ever warmer. It's a vicious cycle, as yeast LOVE warmer temperatures but produce off-flavors in the finished beer when they get too warm.

Cooler fermentations tend to produce the best tasting beers, and the temperature is crucial.

If an ale ferments wildly at 64 degrees, it should still taste great. If an ale ferments wildly at 75, it will probably have off-flavors due to the temperature. Most ale yeast strains produce the best tasting ales when fermented under 70 degrees.

 

[boicutt]

I remember reading a thread on these forums, someone doing a fermentation test at 3 different temperatures within the yeast range to test this out exactly. I'll try and find it and post back the link, but I remember the throughout the fermentation, they tasted slightly differently, but in the end when the beer was ready, bottled and cooled that they all tasted the same.

 

[Bob]

Some observations:

While true that higher temperatures can tend to influence the time spent in vigorous ferment, it's not always the case. It's certainly not so universal as to make a blanket statement like "fast ferments are caused by too-warm conditions". Yes, it's possible. It might even be useful to conclude that homebrewers who experience fast ferments are more often than not fermenting too warm. But blanket statements are always false.

The time spent in the vigorous ferment is immaterial. You can have an excellent-quality beer which stops the vigorous ferment in 24-48 hours.

There are too many variables involved for time to factor much at all. For example, most homebrewers confuse "slow" with "I didn't pitch enough yeast". An underpitched beer will take longer to ferment. Overpitching can lead to too-rapid ferments and off-flavors. Brewers who make the mistake of knocking out onto an existing yeast bed - which is almost invariably overpitching - often see very rapid ferments.

Aeration does not even correlate to increased lag time, much less have a causal relationship. Proper aeration should cause a decreased lag time, because you're adding more of something the yeast needs in its reproductive phase.

I regularly experience beers fermenting to within a point or two of the final gravity within 48 hours. Pitch an appropriate amount of yeast and watch it go. And that's with temperature control accurate to within +/- 1 degree Fahrenheit.

Higher-gravity worts tend to take longer to ferment than "normal" worts. A 1.050 or lower wort, provided sufficient aeration and yeast nutrients, can easily ferment to completion within 48 hours even in the lower range specified to a yeast strain.

The exact strain of yeast has an effect. Some yeasts are more vigorous than others. English strains seem to be fast, American strains slightly less so, Belgian strains even less so, and lager strains, well, they're lager strains. They're supposed to take longer.

That's my take, at least. For my work, it behooves me to turn around beer quickly, within QC constraints. If I can start chilling a unitank after 72 hours - enough time to get full attenuation and a short "cleanup" phase - that's me doing my job well. I hardly think that's objectionable. It's certainly rather poor reasoning to imply that world-class beer can't be produced in 10-14 days from grain to glass.

Cheers,

Bob

 

[paperairplane]

I think pretty much everyone agrees that proper amount of yeast and temp control have the largest effect on making good beer once you understand basic sanitation.

It takes as long as it takes. I use US05 in most of my beers and the big ferment is usually over in 3-4 days tops. I leave all mine in primary for 3 weeks, cold crash and keg. I try to keep beer temp under 65 those first few days, then bring it up to room temp for the rest.

Or just make saison and find the hottest room in the house...

 

[Demus]

I'd add wort composition as a variable as well. Lower mash temperatures of simple base malts will ferment quicker than dextrin favoring warm mashes with lots of adjuncts for example...


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[nevertrustahipie]

In my experience the faster the fermentation the less "yeast flavors" I get (esters/phenols), and vice versa (though, not significant). However this is not a strong correlation. Following proper (and consistent) process and procedures is going to have a much stronger correlation than fermentation time.

Also, i've never brewed a batch and factored the "desired fermentation time." I aim for other factors (pitch rate, temperature, etc.) and have noted the fermentation time that happens.

 

[whooody]

It takes as long as it takes. I use US05 in most of my beers and the big ferment is usually over in 3-4 days tops. I leave all mine in primary for 3 weeks, cold crash and keg. I try to keep beer temp under 65 those first few days, then bring it up to room temp for the rest.

Is there a benefit to leaving it in the primary after the fermentation is complete?

I'm new to homebrew and have just brewed my 3rd extract batch. I've been trying to determine when to bottle. I just did a gravity reading yesterday and had hit my projected final gravity on the 5th day (I'll check tomorrow to make sure it is the same and fermentation is complete). Assuming the fermentation is complete what is the advantage of leaving it in the primary for another 2 weeks?

Hope this isn't off topic.

 

[pricelessbrewing]

The yeast clean up after themselves, clearing the beer, reducing green/off flavors, and allows to ferment as much as they wil.

Yeast don't care what the expected fg is, they may go a couple points lower than expected.

 

[Bob]

Is there a benefit to leaving it in the primary after the fermentation is complete?

I'm new to homebrew and have just brewed my 3rd extract batch. I've been trying to determine when to bottle. I just did a gravity reading yesterday and had hit my projected final gravity on the 5th day (I'll check tomorrow to make sure it is the same and fermentation is complete). Assuming the fermentation is complete what is the advantage of leaving it in the primary for another 2 weeks?

Hope this isn't off topic.

There are many benefits to leaving the beer on the yeast for a time. Listing all those reasons is beyond the scope of this thread, but I'll mention one. Yeast throw off all manner of flavor-impacting chemicals during fermentation. Some of them we want, others not so much. Leaving the beer on the yeast for a while after the vigorous primary ferment is complete will allow the yeast to "clean up after themselves".

Okay, one more. As I'm certain you're aware, aging has an effect on beverage alcohol, including beer. The process of just sitting there changes the beverage's character over time. Beer ages differently in bulk than it does in a smaller package: It matures faster.

So yeah, you can package as soon as you flat-line. But experience proves that leaving it to mellow for at least a couple weeks generally improves it.

Of course there are exceptions to that rule. Some beers are best consumed when still slightly fizzy from the ferment (like Witbier).

Cheers,

Bob