long and slow, or hard and fast?

I am wondering what everyones input is on the speed of fermentation they prefer to see. I am currently fermenting an alskan amber clone and my past few brews have all had a diacetyl off flavor from my ferm temps getting warm. This my first time really making an extremely concious effort at fermentation temperature control (64-68 degrees). Anyways this has been been bubbling away slowly for a week now. The airlock bubbles every 20 seconds or so. Normally my fermentations start off extremely fast. I realize that I have a slower fermentation due to lower temps and I am not worried about this too much. I have heard varying this about this from some people saying that they want the yeast to do its job as quickly as possible to others stating that a slower fermentation allows the yeast more time to clean up off flavors My question is this, do you guys prefer a longer less aggressive fermentation or a faster more aggressive fermentation? Pros? Cons?

Ps sorry for spelling/gramatical mistakes. Posting from my phone makes it harder to edit and its too early to comb this.

A quick start is all I really care about. Aggressive fermentation is fun to watch, but I give my beers plenty of time anyways.

Different strains of yeast will go about it however the heck they want, and even yeast cultures of the same strain often will. They don't care what I think. I treat them well by providing good aeration and yeast nutrient, and maintain the temps that seem to be ideal for the style, and as long as they get the job done, I'm happy.

I guess I just don't really pay attention to the length of time of fermentation. Sure, it's something I notice, but it takes back seat to many other concerns that actually have to do with quality of the beer.

I use 1968 in a lot of my beers, and if I want something with more subdued esters, then I have to ferment around 62-65. This, of course, makes it take longer. I could finish it faster if I fermented at 68, but then it would be a different beer.

And as a note of advice regarding the diacetyl, good job taking the initiative with temp control, but you will help reduce the diacetyl if you raise ferm temp towards the end of fermentation. My yeast is a quick fermenter, so I'm usually ramping my beers up a couple degrees on the 3rd or 4th day of fermentation, when the krausen has mostly fallen. By the time it LOOKS done, I'm at 72, but I still wait a couple more days to cleanup diacetyl.

MrMeans said:

I am wondering what everyones input is on the speed of fermentation they prefer to see. I am currently fermenting an alskan amber clone and my past few brews have all had a diacetyl off flavor from my ferm temps getting warm. This my first time really making an extremely concious effort at fermentation temperature control (64-68 degrees). Anyways this has been been bubbling away slowly for a week now. The airlock bubbles every 20 seconds or so. Normally my fermentations start off extremely fast. I realize that I have a slower fermentation due to lower temps and I am not worried about this too much. I have heard varying this about this from some people saying that they want the yeast to do its job as quickly as possible to others stating that a slower fermentation allows the yeast more time to clean up off flavors My question is this, do you guys prefer a longer less aggressive fermentation or a faster more aggressive fermentation? Pros? Cons?

Ps sorry for spelling/gramatical mistakes. Posting from my phone makes it harder to edit and its too early to comb this.

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Personally, I try to stay at the lower end of the temperature range of the yeast I'm using. For lagers, raising the temperature in later stages reduces diacetyl, which doesn't seem to be much of a problem with most ales.

As for cleaning up off flavors, sitting on the yeast for a minimum of a week after active fermentation is done works well. Many of us have gone to long primary and no secondary for that reason.

If a faster and more agressive fermentation is due only to higher temperature, I'll take the slower and calmer every time. If a slower fermentation is due to not pitching enough yeast, I'll take the faster every time.

The results of different fermentation temperatures with a particular yeast need to be judged by the brewer. I doubt you will find anyone who will argue the fact that pitching the proper amount of yeast will net the best results regardless of temperature.

Who the hell's not pitching enough yeast?

But seriously, I wish there were an easier way to bang the importance of pitching rates into new brewers' heads. Not pitching enough yeast is like trying to make an IPA with 30IBUs.

I think it's like the story of the turtle and the hare- slow and steady wins the race!

Here's why- first, two of the most important things are the amount of yeast pitched and the temperature of the fermentation. That is all about yeast health and flavor.

If you pitch the correct quantity of yeast (around 0.75 million cells of viable yeast, for every milliliter of wort, for every degree Plato) that will be the optimum amount of yeast for that fermentation.

The second issue, temperature, is just as important. Keeping the fermentation temperature below the maximum optimum temperature recommended for that yeast strain is critical. I like to keep it near the bottom of that range, instead of the top, because it gives a much "cleaner" flavor and reduces the esters and other yeast flavors.

The reason I like a slow and steady fermentation (if I can get to choose!) is because fermentation produces heat itself. That means that if I'm already at the edge of too warm (like 70 degrees) and fermentation goes fast, it'll get hotter. When it gets hotter, fermentation will go faster, which will in turn make it hotter inside. It's a vicious cycle, and when I see an explosive fermentation on this forum, I always was "what's the beer temperature right now?" and it's often too high.