mash 15 min @ 150F?

Experienced homebrewer gave me a recipe for his favorite all-grain pale ale. Nothing terribly unusual about ingredients (9 lbs Gambrinius Pilsener, 3 lbs flaked rice, half lb flake maize for 5gal). He is adamant: Mash 15 minutes at 150F. Can that possibly get any saccharification?

faustmeister said:

Experienced homebrewer gave me a recipe for his favorite all-grain pale ale. Nothing terribly unusual about ingredients (9 lbs Gambrinius Pilsener, 3 lbs flaked rice, half lb flake maize for 5gal). He is adamant: Mash 15 minutes at 150F. Can that possibly get any saccharification?

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Certainly some saccharification. The question is, will it result in enough? You could do an iodine test to find out. Or use a refractometer if you have one. Or possibly the method he is shooting for is one to get full malt flavor with less alcohol. I believe Stone Levitation is only mashed for 10-20 minutes.

That's probably the first time I have heard of it in a recipe, but yes, there will be at least some conversion. Especially if you dough in low and bring the temp up to 150. Same for the sparge. If it takes a while to get to Mash out temperatures conversion will continue.

But any way you cut it my guess is that the attenuation will be lower than your typical ale, although that's not always bad.

See Mash Temperature on my blog. My book has some much better graphs than the blog.

15 mins seems definitely on the low side. That being said, there was an excellent interview this week on BN's Session podcast with Damian "Damo" McConn of Minnesota's Summit Brewing Company. In the interview he talked about modern 2 row malt varieties, esp US (Gambrinius is Western Canada), being almost "over modified" and having much more enzymes than found in UK malts, resulting in 20 minute conversions.

I agree with the other posters that gravity and starch conversion tests should be your guide and let the time be more of a suggestion.

Please let us know how your brew goes, I'll be interested in knowing how a Canadian pilsner malt compares to a 2 row US pale malt.

I appreciate all answers. I can tell you how his brewing went; I drank a glass. It is a very flavorful ale.
Brew-Jay shares my thought; maybe body & flavor w/o much alcohol. Woodland, he does infusion, no doughing in.
I will ask him about his OG & TG. That may shed some light.
BTW, he says it was his great-grandfather's recipe (probably not Gambrinius) used during prohibition days.

If anyone is interested, recipe is malts as above, 2oz Magnum hops for 90 minutes, 2 oz Crystal or Liberty at knockoff, Wyeast 2112 yeast, ferment at 60-65.

The amount of time for full conversion is related to the quality of the crush. I experimented with that using a very fine crush with my BIAB system and did an iodine test to see when the starch was converted. The intent was to test every 5 minutes until there was no starch indicated but I got distracted and got my first sample at 7 minutes into the mash instead of 5 minutes as planned. It was already converted by then! Yes, less than 7 minutes for conversion. I have heard people say that beta amylase works slower than alpha but they never put a number on how slowly it works.

I've thought about testing Alpha and Beta amylase conversion rates by pulling samples every few minutes and immediately boiling them in test tubes to stop conversion. Preform an iodine test. Then half could then be fermented with EC-1118 (or something else that doesn't ferment long chain sugars). The other half with typical ale yeast. ... Maybe some day.

The idea of short mash times comes from commercial brewing, and like much of commercial brewing is not necessarily applicable to homebrewers. A commercial brewry will take an hour or so to mash in and maybe a couple hours to sparge, and even more time to get to a boil. So fro them, a 20 min. "rest" is all that's necessary since they're also in conversion range for hours more. That isn't true of homebrewers. My own experience is that I prefer the beers I mnake when they have a longer, not shorter, mash.

RM-MN said:

The amount of time for full conversion is related to the quality of the crush. I experimented with that using a very fine crush with my BIAB system and did an iodine test to see when the starch was converted. The intent was to test every 5 minutes until there was no starch indicated but I got distracted and got my first sample at 7 minutes into the mash instead of 5 minutes as planned. It was already converted by then! Yes, less than 7 minutes for conversion. I have heard people say that beta amylase works slower than alpha but they never put a number on how slowly it works.

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I wonder, though, with a 150 degree mash and 40+% adjuncts if there would be complete conversion in that time. I would think not. I think that it would take longer with adjuncts.

I've never tested for conversion when using adjuncts, but often go with a 75-90 minute mash if I'm using a lot of adjuncts and a cooler mash temp. It's one of those things that might not be strictly necessary, but certainly can't hurt and could very well help- so I do it.

I usually check how conversion is going every 15 minutes with a refractometer and typically it's at least 70% after the first 15. The remaining 30% can take much longer. If you don't do a mash out rest, you're getting conversion during vorlauf and sparging too. For a recipe like a Helles with mostly Weyermann Pils Malt, it's over 80% after the first 15. I condition the grain before milling at 0.028" so YMMV.