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Protein rest = efficiency boost

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Shawn Hargreaves

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I brewed my Wit again yesterday, but included a protein rest (20 minutes at 122 degrees, then 45 mins at 154), where in the past I've just done a single 60 minute infusion.

I normally get between 70% and 75% efficiency, but this time I got 83%!
 

KYB

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Good to know. My next Stout I think I'm going to do a PR. I think I could get pretty damn good efficiency doing that and a few other things better. We'll see..
 

barely

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Interesting - I had the same thing happen to me. I got 88% efficiency using a protein rest, where my previous beers have been 75% eff MAX. It was also my first all-grain with wheat and acid malt, so I wasn't sure what the big contributor was to the efficiency (wheat, acid malt, or PR). I am going to give serious consideration to doing a PR more often.
 
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Shawn Hargreaves

Shawn Hargreaves

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I use acid malt and wheat in my wit, too, but I've used those before without the rest, so in my case this was pretty much an exact side by side comparison of an otherwise identical process. I've done the same mash a couple of times without the protein rest and only got a few percent variance in efficiency, so I'm pretty sure the rest is what made this big difference.

Now the waiting to see how the final beer comes out! It'll be a little stronger than I was planning, but I wonder how the flavor and body will be affected, if at all?
 

Kaiser

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Yes, you may see an efficiency boost from a protein rest. But only if your previous mashes didn’t convert all or close to all starches in the grain. The low temp rest helps the amylase enzymes and starch get hydrated before they get to a temp that provides thermal stress to them. It may also break down some proteins that infest the starch and make it less accessible.

This being said, I don’t think that you should look at a protein rest as a fix for low efficiency unless you have malt or a grist that requires it. It may be beneficial for a Wit but not what you want to do for a Pale Ale.

I’m putting this out here just in case the wrong conclusions are drawn. BTW, has any of you measured the gravity of the first wort?

Kai
 

Homercidal

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I think that wheat is one of the grains that will get a boost from a protein rest. I read this past weekend where it is usually not a benefit to the average malted grain.
 

lamarguy

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I think that wheat is one of the grains that will get a boost from a protein rest.
Unmalted wheat may get an efficiency boost. Conducting a protein rest for malted wheat isn't advisable.

I read this past weekend where it is usually not a benefit to the average malted grain.
Correct. Like Kai said, conducting a protein rest for well modified grain is not advisable. In fact, conducting a protein rest for well modified grain may result in poor head and body.
 

KYB

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Well now I don't know if I should try it or not. I know Guinness does a Step Mash, however the grains I get from Midwest are well modified, correct?
 
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Shawn Hargreaves

Shawn Hargreaves

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A dry stout has unmalted barley, which could benefit from a protein rest, but then with a stout you want those proteins to fill out the body of the beer, so perhaps you don't want to convert them too well. I have no clue, in other words!
 

hukdizzle

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I have been contemplating doing this but I just got 83% house eff on the most recent brew and 94% into the kettle, I can't really complain. I mostly want to do a PR for the head retention but I have heard that it helps with the efficiency as well.

One thing that I am sold on is grain conditioning, I will be doing it on my next batch with 2.5 oz of water to 10lb of grain, let it sit for about an hour then crush. Not only can the mill be tightened down for a finer crush (more readily accessible starches for conversion), but the bigger husks left over due to the conditioning are great for lautering and almost eliminate the need for rice hulls. As long as you are very conservative with the water and thorough in the mixing of the grain while conditioning you shouldn't have any issues with mill dough balls or anything.
 

Saccharomyces

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Protein rest or a cereal mash is a requirement if you are using raw unmalted wheat, you need to gelatanize the starches so they will fully convert in the mash. If you are doing a single infusion mash you should get close to optimum efficiency with flaked unmalted wheat or torrified wheat, since those products are pre-gelatanized, but I have found I still get a ~5% boost in yield with a step mash using pre-gelatanized wheat at 40-50% of the grist.
 
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