Fermenting ale yeast at lager temps

[Pupowupo]

So I have a Porter and an IPA fermenting in my garage at an average of 48º F, I used Safale US-05 for both. The Porter has been sitting for three weeks and the IPA for two.

Besides the batches taking longer to finish, are there other setbacks storing ales at this temperature? I've experienced a cleaner taste when fermenting and conditioning ales at lower temps as well as a much less violent fermentations with higher gravity beers, so I kind of prefer it. Just wondering if I'm messing anything up by doing this.

 

[Hello]

If you've been doing it this way and you're happy then stick with it. However, if the yeast isn't sitting in the optimal temp range, such as it is way colder than it should be, you're not giving the yeast a chance to be healthy. Also, I do think you could risk infection because the yeast isn't working how it should. I could be wrong about that. What would worry me is if you bottle and the yeast wakes up with the warmer temps that you'll need to carbonate your beer.

 

[Yooper]

I would be surprised if either S05 or most other ale yeast could actually ferment out a beer at 48 degrees. That's even on the low end for lager yeast!

If your beers are actually fermenting, and tasting good, then that's great. But I suspect it's more likely that the temperature is fluctuating and at times the temperature is far higher than 48 degrees, if you're getting fermentation at all.

 

[slym2none]

Yeah, I'd think that most ale yeasts would just shut down at those temps. But what the heck do I really know?

(Answer: nothing)

 

[Gavin C]

S-05 seems to be used at a wide array of temperatures with success reported by a lot of brewers.

If it's fermenting and reaching attenuation levels in the normal range you're likely in good shape.

What I would suggest is to bring the beer in from the cold when the krausen drops and the SG is a little above projected FG. This slow passive warming at room temperature may ensure optimal attenuation and a more complete fermentation eliminating any risks of bottle bombs when you subsequently package the beer.

I'm not sure I would share @Hello 's concerns regarding the warmer yeast temperature in the bottle and bombs but I can definitely see the logic there. I would make sure SG was stable and the beer was at FG prior to bottling.

Some ale yeasts are very happy at temperatures in the 50's. WLP029 and WLP036 are two strains I have used with some tasty results.

These days I tend to steer clear of S-05.