15 Min. Mash?

I'm not sure I've ever had that beer, but the result of a 15 minute mash will be a less fermentable wort, resulting in a higher final gravity, compared to a longer mash. It's probably long enough for starch to sugar/dextrin conversion, assuming a reasonable mash thickness and relatively high diastatic power from your base malt.

 

This may be Deschutes method but this practice is based more on high production brewing. Mashing that high, 160F, 1# of Crystal, and only doing it for 15 minutes will limit B-Amylase activity highly and you will end up with a less fermentable wort.

 

If Deschutes gets the fermentabilty they are looking for using that mash schedule and the exact same ingredients, you should be able too also.

 

IIRC they have a 150 bbl system. As they mash in over what, a half hour (?) the grist is converting. As they go to mash out and run off, the grain is converting. 160F with a high DP NA base malt and you are good to go. From start to end they are at temp for about an hour or more. We have differences due to our little systems.

Edit - I would not try it with Maris Otter or German malts.

 

Not a sweeter wort, but a sweeter beer.

 

Good point. I should have said "with an equivalent conversion time."

 

this months zymurgy has a clone for fresh squeezed... I would refer to that recipe.

 

Don't forget that mash times in commercial brewing do not translate at all to the homebrewing scale. Often times in commercial settings, it takes an hour to pump from one tank to another, takes another hour to get up to a boil, etc. In a homebrew setting, the mash needs to be lengthened relative to commercial because we can do all those other things so fast. So, Deschutes 15-minute mash is likely the equivalent of a full 60, if the info came straight from the commercial brewery.

 

Good point, the big Brewers have mash tuns and separate lauter tuns. They mash in, rest, then pump to the lauter tun. Then they lauter once the goods are transferred. They are mashing for longer than 15 minutes if you think about the time temp profile. As soon as a mash goes to the Lauter tun, a new mash is started while the previous Lauters, as that is how they get throughput.

 

In my limited commercial brewing experience (one 10 bbl brewery and one 15 bbl brewery), it generally takes 1.5 - 2 hours to lauter the wort for a 10 - 15 bbl batch depending on the commercial system used. While collecting runnings in the boil kettle, you are also heating them up. The goal is to be at a boil immediately as you've collected your runnings in their entiriey. So I'd say that the conversion that starts to happen in the mash kettle continues to happen to the beginning of the runnings that are collected in the boil kettle. As the kettle heats up, it soon gets hot enough to denature the enzymes in the subsequent runnings as they enter the boil kettle. Fortunately, those subsequent runnings spent a longer time in the mash kettle than the first of the runnings. Based on that and the sheer length of the lautering time, I wouldn't be surprised if using a significantly shorter mash rest time resulted in no real difference in conversion on a commercial level. As the batch size (and runnings time length) increases, the mash rest could be shortened more. So it seems plausible to me that a brewery making batches as big as Deschutes is could do a 15 minute rest. On the commercial systems I've worked on, the SOP's have been 45 - 60 minute rests for most styles, but my gut feeling is that a mash for a 10 - 15 bbl batch could successfully be shortened to 20 - 30 minutes without conversion issues. Maybe I should do an iodine test sometime

 

D, I think you'd agree that iodine test doesn't always tell the whole story. You want conversion, but that doesn't mean enzymatic conversion it complete....oh....that is what the smiley meant....

I'll interject my own story...not long ago I brewed a recipe I've brewed before (an IPA) that I thought was thin bodied, so I upped the mash temp to 160F for the new batch. Unfortunately for reasons that escape me now, the total mash time was much longer than what I planned on, ended up like 45-60 mins instead of 20-30 mins. With Nottingham yeast, it still finished at 1013.

 

I'd be lying if I denied being called "cheeky" at times.

 

P.S. Vorlaufing time also extends the mash period

 

FWIW, Notty is a strange beast. I find that this yeast uniquely always very reliably attenuates to 77-78%, regardless of mash time or temperature.

 

I only mash 20-30 minutes for most of my beers. But with vorlaufing and sparging and kettle heating the total conversion time is more like 60 to 75 minutes. Cutting my mash time to 20-30 has had no impact on my beers, but it has saved me a little time on brew day.

 

Similarly but differently, I BIAB but about 85% of the time I only mash for 40 minutes to save time on brew day. Many experiments have proven to me that this has undetectable impact on conversion or attenuation. I could mash for a "full 60", but why? Save 20 minutes every time. So maybe that's part of this whole thing, too -- if the brewer knows better, maybe they want to save time.