Low Mash (136) in a Brett Saison

[Wernerherzog]

Broke my glass thermometer on brew day and ended up using a digital thermometer. Didn't realize it was off by 11 degrees until the end of the brew day when chilling. I tried to ferulic acid mash, thought I overshot and ended up at a 118 reading (actually 107). 40 minute rest and decocted to raise the temp to a reading of 147 (actually 136) for 60 minutes. Efficiency was consequently real low, 59% and I ended up with a 1.040 beer.

I'm working with WLP565 and am planning to pitch brett when the Saison Yeast stalls.

Can someone help me think through the effects of the low saccharification temp on the fermentation and end result?

Will the yeast end fermentation way earlier? Will this just leave way more starch for the brett to chew on? I really wanted good phenolic formation for conversion into funk and am concerned the yeast may not be as productive due to the lack of short-chain sugars.

 

[brewjack]

I think you'll be fine. 1.040 is on the low abv end for American saisons but I personally like them in that range.

I think you have the short vs long chain thinking backwards. Since your mash was low the mash will have converted by basically %100 beta amylase, and it's the higher temp alpha amylase that results in longer chain sugars.

Here's a nifty chart I found:

http://missionarybrewer.files.wordpress.com/2012/02/enzyme_activity_one_hour_mash.jpg

I think your beer will come out fine, if anything though you might have less long-chain sugars for the brett to chew through, so your beer may come out "cleaner" then you were hoping for.

Good luck! And keep us updated on the FG of the saison strain. I'm curious...

 

[Wernerherzog]

I'm concerned that I went too close to the low-temp threshold for even beta amylase, which would leave many unconverted starches right? According to your chart my wort is around 62% fermentable. My guess is that the brett will destroy anything left by the saison yeast anyways. Visible activity has halted but I haven't taken a sample. Lifted the temp from 71 to 80, so we'll see if that helps.

Boatloads of spice and clove.

 

[Wernerherzog]

In any case, here's a bit more info on temp schedule and results thus far:

Brewed Thursday Night, day 0- Pitched at around 75 (hot ground water)
Friday Midday- day 1- 77 degrees, visibly activity, removed bucket lid as suggested by others with 565
Saturday AM- Day 2- 71 degrees, down from ambient temp drop over night, added heat pad
Saturday PM- 80 degrees, re-latched lid since activity is no longer visible
Sunday- 5PM- 79 degrees, stirred up the yeast to try and get more activity

Reading taken on Sunday says 1.008 down from 1.039, 79% attenuation.

Sample was grainy/bready perhaps from all the remaining starch? Has a nice twang that isn't quite tart, familiar to many saisons from my experience. Familiar clove and pepper and good body.

Will grow some colonies of brett and toss in with some cooked down rhubarb soon to eat up the rest of those sugars and starches.

 

[brewjack]

I had to take another peak at that chart I posted after you mentioned that 68% fermentabilty bit. I found that chart because I was curious of the temp range for alpha and beta amylase. I think the bell-curves are representing the ideal productivity of the enzymes not the percent of starches they can break down. In other words at 137* beta amylase is working 68% as fast as it will 142*. The actual fermentability is just that little green line (which doesn't seem that helpful).

My understanding is that if mashing with beta amylase (low temps), your wort will be more fermentable than if mashed with alpha amylase (high temps). Since you were extra low temp, you'd be mashing exclusively with beta, and the only question would be if the mash was able to complete in an hour. My guess would be yes. (I've heard from knowledgeable brewers that almost all enzyme activity of a mash is usually complete within about 15minutes!)

79% attenuation sounds good, Saison strains can definitely go farther, but since you're adding brett, I wouldn't want it to. I'd want there to be something for the brett to chew through.

Sounds like it's going well to me!