Protein rest success and questions

I've been having problems with efficiency (in the 50's) and stuck runoffs with recipes using a lot of flaked rye and oatmeal. For an oatmeal stout today I decided to try a protein rest for the first time. Here's the recipe:

9.00 lb Munich Malt - 10L (10.0 SRM) Grain
1.00 lb Oats, Flaked (1.0 SRM) Grain
0.50 lb Black (Patent) Malt (500.0 SRM) Grain
0.50 lb Chocolate Malt (350.0 SRM) Grain

Protein Rest: Add 9.90 qt of water at 132.1 F
- Hold mash at 122.0 F for 30 min

Saccrification: Add 8.80 qt of water at 206.7 F
- Hold mash at 158.0 F for 30 min

-- Sparge with 3.93 gal of 168.0 F water.


So I put the 9.9qt water in my MLT and when the temp came down to 132 I doughed in. The temp stabilized about 124F and I left it for 1/2 hour.

I then brought 9qt almost to a boil (my thermometer read 208) and pumped it into the mash. After vigorous stirring it stabilized down around 148F. I had to boil more water and pump in a lot more water to bring up the temp just to 154F.

So never having done a protein rest before, should I have done something different to get the mash temps to follow what Beersmith caluclated above?

I'm also wondering about you guys who use a separate HLT, how do you control the temp and volume that ends up in the mash?

The good news is the protein rest seems to have done its job. I had great flow during runoff of both my first runnings and my sparge. I also got 74% efficiency.

-Joe

Congrats on getting your efficiency up. I thought if you go past 170 the enzymes are shut down? Could the time it took to get the temp from 208 to 154 shut down some enzyme activity?

I've been reading up lately on step mashing & protien rests. There's some good info here on HBT :

https://www.homebrewtalk.com/f128/protien-rest-142937/#post1639189

Seems the general concensious is that it can be beneficial, especially with lots of unmalted adjuncts, but be careful how long you do the protien rest, seems 30 minutes might be a little too long.

Thanks XXguy for the link!

My w/e recipie (purchased kit) had a 30 min protien rest in the recipie... I didn't calculate any efficencies or such, but if I hit my target OG... then I figure I'm 100% efficient... =) he he hehe.

Time to read up more.....

Thanks gang. Any input on the questions I had?

nostalgia said:

So never having done a protein rest before, should I have done something different to get the mash temps to follow what Beersmith caluclated above?

I'm also wondering about you guys who use a separate HLT, how do you control the temp and volume that ends up in the mash?

Click to expand...

Thanks!

-Joe

Good job!

Do you know what company your malt is made by?

Most modern highly modified malts only usually benefit from a high side protein rest (133F) which helps with body and head retention.

IIRC a low side protein rest (122F) will help with yeast nutrition mostly.

Either way, congrats!

RighteousFire said:

Most modern highly modified malts only usually benefit from a high side protein rest (133F) which helps with body and head retention...Either way, congrats!

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Thanks! It's not the grain that's the issue. My understanding from my reading/chatting, the highish percentage of flaked oats/rye/wheat in these recipes causes the problems with stuck runoffs and low efficiency. The protein rest gelatinizes the grain and prevents those problems.

-Joe

This is a good point.

If you actually dough in at a low temperature, say 90F-100F than this would cause all of the grains to be easily saturated because you could avoid dough balls as at this temperature you are well under gelatinization levels. You could then raise the temps up to a protein rest and/or a sach rest to completely gelatinize the grains. stirring isn't as big of an issue this way because the grains are already wet, and there is no chance of dough balls.

nostalgia said:

Thanks! It's not the grain that's the issue. My understanding from my reading/chatting, the highish percentage of flaked oats/rye/wheat in these recipes causes the problems with stuck runoffs and low efficiency. The protein rest gelatinizes the grain and prevents those problems.

-Joe

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I think you're mixing several different ideas into one, so lemme share some some things I've learned about protein rests. I used to do a protein rest for every brew, and the only reason is because Papazian says he does the same thing for his brews. Now I NEVER do one.

What does a protein rest accomplish? It does not gelatinize the grain, as you claim above. "Gelatinization," put simply, is when starch molecules break down and burst due to heat. Every type of starch has an approximate gelatinization temp, and while I'm not sure what they are, I'm positive that protein-rest-temps are too low for gelatinization to occur.

Just like a saccharification rest takes advantage of starch-degrading enzymes (amylase), a protein rest uses protein-degrading enzymes (protease). And just like you can denature starch-converting enzymes (around 168*), you can denature protein-degrading enzymes (around 140 I believe?). So that's why the protein rest comes first - if you immediately bring your grain to saccharification temps, you start denaturing protease enzymes off the bat.

In a grain, there are all sorts of sizes of protein molecules. When you do a protein rest, the protease breaks down larger proteins into smaller. Ideally, you want a mix of sizes for good head retention. So that's why people have done protein rests in the past.

There may be a reason not to do protein rests nowadays. Today's malts are very well "modified," meaning they have been allowed to germinate (grow roots) for quite awhile, especially compared with ancient malting techniques. When a grain malts/germinates, it begins producing and activating the very same enzymes that we use during mashing. These enzymes slowly begin to do their performed functions, though because they're not at their optimal temperatures, their work proceeds very slowly. The point is with modern malts, you've already accomplished some breakdown of the proteins. If you do a protein rest, you may be further breaking down the proteins until you're left with nothing but tiny protein molecules. This is just as bad as having too many large proteins - your head retention (and body/mouthfeel) will suck.

So like I mentioned, I used to do protein rests with every beer, but I noticed that my head-retention sucked. So I stopped, and it improved.

But now onto your actual problem - low mash efficiency. I noticed you did a 30 min protein rest and a 30 min saccharification rest. That second rest is very short. I always do a minimum of 60 minutes, and then let it go longer if an iodine test indicates that starch conversion is not complete. I think you need to lengthen your sacch rests and you'll find your efficiency increases.

Also, make sure you're using a minimum of 1.25qts/# of mash water, but I definitely get better efficiency the more I use. I never use less than 1.4qts/# these days, and usually 1.5-2. I think one benefit you're getting from the protein rest is hydration, not gelatinization. The more hydrated your grains are, the easier it is to convert sugars. Again, a reason to use more mash water.

Finally, regarding problems hitting your temps - I don't think this is something that anybody will be able to give you perfect advice on. Just take lots of notes between each batch and you'll figure out the heat loss of your system. Couldn't hurt to have a small pot of extra boiling water on the side in case you have to correct. Oh, and cover your pots when you're boiling strike water - one problem I had early on was heating my strike water too early and then losing a bunch to evaporation.

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kanzimonson said:

There may be a reason not to do protein rests nowadays. Today's malts are very well "modified," meaning they have been allowed to germinate (grow roots) for quite awhile, especially compared with ancient malting techniques.

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This I understand. The only reason I tried the protein rest is because this recipe used flaked oats. All of the AG recipes I've done that use flaked wheat and rye have had runoff and efficiency problems. I did a lot of reading here and spoke with other brewers and many recommended the protein rest whenever using unmalted grains like flaked oats/rye/wheat.

For example, in How To Brew, Palmer talks about much of what you typed above with the caveat:

This rest should only be used when using moderately-modified malts, or when using fully modified malts with a large proportion (>25%) of unmalted grain, e.g. flaked barley, wheat, rye, or oatmeal.

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So this recipe doesn't quite use 25%, but I wanted to try it anyway and see if it helped. Which it did. So I'm pleased with the protein rest part, I just had the temp problem.

Apologies if "gelatinization" was not the proper term.

-Joe

In spite of Palmer and the others that disapprove of protein rests,
I started using a 15 min rest at 122 for my wheat beers which
are usually about half malted wheat.
I haven't had a stuck sparge since and I like these beers better
than the ones I made with a single infusion mash.
I don't think they're thin and they have a thick, creamy head.
YMMV

Great post by kanzimonson. The reason you get dough balls when you dough-in at higher temps is because of gelatinization. The hot water gelatinizes the starch on the outside creating a 'shell' and water can't penetrate to the inside.

One thing I would add is that the thing that causes stuck sparges with Flaked Oats is Beta-Glucans. And there is an enzyme, beta-glucanase, that helps break them down so you don't get stuck sparges. The temp range for beta-glucanase is about 95 F to 112 F or so...just below typical protein rest temps. When I use a lot of oats or flaked barley I do a beta-glucan rest but if I use a lot of wheat (esp. unmalted wheat) I do a 'regular' protein rest (but on the high side...like 133 or so...and not too long). Otherwise, no protein rest.

Here's a chart from Palmer's How To Brew:


And here's another from Kaiser's site...the enzymes are active within a 'fuzzy' range so the exact numbers (the black, dashed rectangles) might be slightly different than Palmer's:

kanzimonson said:

Couldn't hurt to have a small pot of extra boiling water on the side in case you have to correct. Oh, and cover your pots when you're boiling strike water - one problem I had early on was heating my strike water too early and then losing a bunch to evaporation.

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I only have one burner, so it'd be difficult to keep extra water boiling unless I know the volume I'm pumping. I guess I need to add a sightglass to my MLT.

This is why I had the question about folks who use a separately-fired HLT. I'm curious about how you pump the correct amount of water into the mash and how temps in the HLT are regulated. Hmm...maybe I could make an electric HLT with a thermostat. I <3 new projects

-Joe

Those charts help a bunch SpanishCastleAle... thanks !