Primary Temperature

It isn't "necessary" but raising the temperature as the fermentation winds down is believed to aid attenuation, and help the yeast clean up after themselves more efficiently.

 

I always thought it was a diacetyl rest. This would prevent a buttery flavor in your beer. Some of the English styles of yeast flock like a rock and you may have some trouble hitting FG. Warmer temps would help prevent this a little. What Jonh says above is also very good.

You'll notice a world of difference in how quick your beers shape up if you can keep your temp within a degree of where you want it throughout fermentation.

 

Researching what dialectal rest meant was on my list of things to do, and now that's done: Is it common practice to do that on all beers, certain particular styles of peer, or is it really just the brewers preference? I would think this would be done mostly with really light crisp beers that are fermented at low temps, and light tasting. Like Lagers and pilsners. Or maybe scotch ale?

 

Yup, that's what I meant by "clean up," but you were more specific

 

Certain ale strains are known to produce more diacetyl, and precursors, than others, and lager yeast even more so. For yeasts not known to produce much, it's more or less not necessary, also if you're not fermenting particularly cool.

I do it out of habit more than anything.

 

I think @CADETS3 said he was using WL 002 in another post. How would one know if a particular strain would produce more diacetyl than another. I looked around white labs but I didn't see anythign that said anything.

 

It's mostly English strains...White Labs mentions it in the descriptions of a few of them, such as WLP004.

 

Mostly it causes the yeast to produce more esters and phenols. These are not necessarily off-flavors, but may not be desirable in the style you're brewing, or too pronounced for the style. However, if you go too hot you'll also produce fusel alcohols, which are undesirable.

 

I only pull an intentional diacetyl rest on lagers. Since I bottle condition my beers I figure they get enough time sitting around at room temp anyway.

 

I used to use the 'swamp cooler' method when I started brewing. When I went to a chest freezer and temperature controller it was much much easier for me to get repeatable results with the same recipe. It of course also allowed me to ferment lager yeasts at the correct temperatures which is difficult in Texas most of the year.

 

Out of habit, I tend to run most ale strains around 63 or 64 for at least 3 days. Then I ramp the temp up to 68 to finish them off. What's the harm in doing a D rest on a strain that doesn't need it, when most of the flavor profile is created in the first few days ayway?

 

You know what would be perfect for those 70's temps? Saison. Just let get to what ever temp it gets to. Maybe a heffe too. They both ferment so fast, on the warm side, and don't really gain a bit benefit from sitting in bottles for a few months like a stout would. Honestly with us being in Texas, and consistent triple digit heat going on right now, saison is the way so go. Unless you are using a keezer, I would hold off on making stouts if it were me. At least until it cools down in October.

I will say though: If this batch doesn't turn out right, let your bottles of stout sit in a closet and forget about then for 6 months or so. I made a batch of porter about 7 months ago and I thought it tasted really off. A few days ago I opened a bottle and it was freaking amazing.

 

I agree about the saisons. I make one with lemon zest and paradise seeds. I would ferment that at 75 or 76 degrees and the yeast loved it. It was the best repeatable beer for me before I got my freezer.

 

I let my saison get to 80-82. I've had several people tell me to let it get to the 90's if it wants to. It's like the yeast just laughs at the heat and turn it into better beer.

 

There's apparently a Wyeast Belgian Saison strain that has a habit of getting stuck at 1.035 if the temp is below 84 degrees.

 

Wyeast 3724 is the one you are referring to. I'm using it right now. I don't know if what you say is entirely accurate as I've never hit 84. It does stall out at 1.03x but it will restart if you are patient. I might also give restart credit to the josling of checking gravity, or heating from 80 to 82. Or both. If you want a hassle free fermentation I suggest either Dan's star belle, or wyeast 3711. So far they both taste identical from nearly identical recipes (single malt (pils), identical water, identical hops and addition times, identical fermentation conditions). They both ferment EVERYTHING down to near 1.00x within a week. Very user friendly.

I feel like I hijacked thread. Sorry about that cadet.

 

I wouldn't want a hefe fermented that warm. I usually shoot for 62 to 67 depending on whether I want more clove or banana.

 

I have used this strain (3724) many times without going above 80F, and it has never got stuck for me. Pitch rate, oxygenation, and nutrition seem to be key. Others have had similar non-problems with even lower temps.