On the Duration of Fermentation Temperature Control

[HerbMeowing]

Style: Pale ale; including Indias.

- Conventional wisdom (CW) tell us to our chill wort to a few degrees below the desired fermentation temperature before pitching yeast.
- Others disagree. Pitching a little above the desired fermentation temperature followed by cooling results in beer just as good as the CW.

What's your process?

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- CW tells us to maintain the desired fermentation temperature for two weeks.
- Others disagree. The target fermentation temperature should be maintained until high krausen has subsided ... then free-rise to ensure good attenuation.

What's your process?

[BigPapaG]

I pitch at or around (lower in winter, higher in summer) the desired initial primary temp.

I then try to hold the initial primary temp for three days or so and then allow it to rise... More easy to control in winter and harder in summer.

I also try to schedule specific styles and yeast strains that can run cooler for winter and others that can handle higher temps in the summer months.

[RickBeer]

I keep at the same temp the entire 3 weeks. Always dry yeast. S05, S04, Notty or Windsor for most.

[bpgreen]

I've also read that it's ok for the temperature be higher for the first day or so while the yeast ramps up.

[mashani]

For most ales - I try to pitch at or as close to my starting temps as possible. It is sometimes below in winter, sometimes a bit above in summer. I try to hold temps for 2-5 days depending on type of beer, and then will let it rise to finish/clean up/d-rest, etc. More often then not my fermentations are actually done in 7 days (or less), and the rest of the time is just "bulk aging" and "looking out for signs of Brett". I pitch lots of yeast, so I often have active fermentation kicking off in 4 hours (and sometimes less) with many yeasts. Belgians when I warm or let free rise, I will push to the high end of yeast tolerance (which is often a good bit above manufacturer recommended temps) by 5 days in. Because it harms nothing, makes great flavors, gives great attenuation. Then if I'm keeping it in the fermenter for a while after it's finished/cleaned up I'll let it cool back down. Many of the best commercial Belgians do the same.

For lagers, kolsch, and other pseudo-lagers - I keep more consistent temps through fermentation except for d-rest.

[Stinkfist]

I think it depends on how much yeast you pitch....If you pitch a good amount of healthy yeast you should pitch below and then slowly warm up to your temp, this will give the best results. If you cannot pitch as much yeast as is needed, then you should pitch slightly above and then again increase as time goes....Pitching high and then dropping the temperature is never good for the yeast and will most likely end up with an under attenuated beer.. yeast does not like temperature swings...especially to the lower end of the their range....you always want to keep increasing to increase activity...If you want a nice clean dry beer..

[MadBrewer]

I typcially pitch slightly warmer than my set fermentation temp. That is usually because I can't cool the wort any further (at least for half the year anyway). Like lastnight I got as low as 68 with my wort chiller. By the time I pitched my yeast my stick on thermometer on the fermenter was looking more like 70*. I typcially ferment my ales about 66* so it's not a huge difference. I had a bit of longer lag time than I'm used to this time around as well so the beer had a chance to come into the right temp range. What I don't try to do or believe is say pitching at 70* then crashing to 60*...that seems like asking for trouble as you might stress the yeast. But a few degrees +/- is usually what I end up with.

Once the fermentation takes off I hold the temp until I see signs of it slowing down. 3-4 days in I bump the temps over a couple days and max out at 68-70 depending. I don't brew many lagers, but lagers I feel it's probably best to get as close to or below your pitching temp for the cleanest tasting beer. Ales are Ales, they are much more forgiving and I haven't noticed better beer enough to make me too picky about it. The beers come out good, never had any problems with hitting FG. I'm sure it depends on other factors as well like yeast type and variety, health and pitch rates, oxygen levels...etc.

[Pudge]

I usually pitch exactly at or slightly below my intended fermentation temp. That is yeast strain dependent. I will hold the intended fermentation temp through 4 days of visible activity. Sometimes a beer will take off quick. Sometimes it can take several hours to a day... or in some cases even a bit more. This is also yeast strain dependent. After 4 days of visible activity, I'll bump the controller up 5-7 degrees for the remainder of two weeks. Fermentation has long been finished and the yeast have done their cleanup work within 2 weeks.

Now some strains, Wyeast 1968 keeps coming to mind, can blow through wort very quickly. I brewed an English Mild once using the 1968 at 64 degrees and flat out missed fermentation. I thought it never started until I took a gravity reading and realized it was done. That is a temperature finicky strain too. Too warm and it gets all English on you. A few degrees too cold and it can drop out and quit altogether.

[ScrewyBrewer]

Yesterday was hotter than I expected with outdoor temperatures in the upper 80's. The yeast starter warmed up to 73F after sitting in the brew room all morning and my wort was chilled down to 78F. I put both fermentors in the chest freezer, set the controller to 73F and about an hour later pitched the yeast into the wort when both were at the same temperature.

After the yeast was pitched and the wort oxygenated both fermentors went back into the chest freezer this time with the controller set to 65F where it will stay set until just after high krausen. I've been following the same practice all summer using US-05, WLP400 Belgian Wit and yesterday with WLP810 San Francisco Lager yeast.

The IPAs and Witbier's fermented this way have all come out tasting good. If there was any differences in taste from doing this way as opposed to using other temperature ranges it wasn't noticeable to me or brought to my attention by anyone that drank the beer.

[Whamolagan]

I pitch at the fermentation temp that I keep throughout the 2 weeks of fermentation until 3 days to kegging, then down to 50 for the cold crash.

[HerbMeowing]

I'll pitch near the middle to top end of preferred range (U60s - L70s) in large part b/c that's the best I can do with a SS immersion chiller and well-water. Well-water temperature is fairly constant year 'round but not so in the holding tank under the house.

The LBK goes into a 48 QT cooler with one or two 22-oz bottles of frozen water.
By morning ... the wort temperature sits in the L60s and fermentation is underway if liquid yeast was pitched or the lag phase is just ending with dry yeast.
Works well for me.

As for the duration of maintaining 'cool' fermentation temperature; there doesn't seem to be any advantage to extending the cool period beyond a day or two past Hi-K.

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A lot of interesting responses.
I'll review and tally them over the next few days ... then report on any consensus and special considerations.

[Pudge]

Seems to me the flavor impact (or lack of) of the yeast is set 2-3 days into active fermentation. After that, it is all about finishing fermentation cleanly.

[BigPapaG]

Seems to me the flavor impact (or lack of) of the yeast is set 2-3 days into active fermentation. After that, it is all about finishing fermentation cleanly.

Mostly this ^^^, but with some strains, additional esters and phenols can be coaxed out later as well.

Many Belgian and Wheat strains notable, although I suspect most any strain, if pushed, will do things beyond the norm.

IMHO.

[Kealia]

I'll add that I also chill to mid range for the yeast strain before pitching. I typically use Mr. Malty to determine my pitch rate, too.
I hold at my desired temp for 5-7 days depending on visible activity (and my schedule) then bump up to the high end of the yeast's temp range, if not slightly over.
I also believe that most of the flavor profile is set during the most active part of fermentation early on and that's when temp control is most crucial..

Before I had an STC-1000 and the ability to micro-control temps I would basically let it free rise in my 68-70 degree closet when I thought the active part of fermentation was over.

Sent from my Nexus 7 using Tapatalk

[mashani]

I do think that most of the flavor profile is set in the first few days, but not all... that's why I will vary my hold vs. ramp up schedule from 2,3,4,5 or what not days. It just depends on what I'm making, what yeast I'm using. I do think BigPapaG is right that you can coax some stuff out of some strains even later if you push temps high enough. It's going to be subtle though. So in a big hopped beer it won't matter. It's in a yeast driven beer IE Belgian or Wheat or such that you might get that slight bit of something extra. There are various yeasts that I will push out of spec on purpose for this reason. But I don't start out of spec. That would most likely produce yuck.