Protein Rest

So, I've been searching all weekend through all my (numerous) brewing books and can't find it.

I know that a protein rest is somewhere in the neighborhood of 120 to 130 degrees. But what is best? Which is to say, what are the advantages or disadvantages of being on the low or high end of that scale? Mashing at 147 is going to give you a very different beer than at 153, but what's the difference between 121 and 128? Does it serve different purposes?

From everything I have seen, and I do PM so I dont really have to worry, its a range from 120 to 132. I have seen everyone doing there protein rests at 122. not sure on effects of +/- temp for your rest

In a protein rest, you're essentially looking for 2 enzymes to be active. I won't go into too much technical detail and this info is from Noonan, but Proteinase breaks down simple proteins into albumins that assist in head formation and retention and has an optimal temp. range of 122 - 140dF. Peptidase dissolves certain albumins into amino acids and is beneficial for yeast growth in early fermentation. It has an optimal temp. range of 113 - 122dF. However, in an all-malt beer, there are generally enough amino acids for the yeast. So, 122dF would get the best of both worlds, but going a little higher will give you better head formation/retention and won't noticably affect yeast growth. However, getting up into the 130's will get you some saccharification as well, so you may want to increase your main saccharification rest temp. into the mid to upper 150's to balance it out (depending on the beer style).

I've read here and there that american 2-row is modified enough that a protien rest isn't neccessary, and can actually do harm by breaking too many protiens. With the continental malts and some UK (MO, GP), the protien rest can be helpful.

What do the more experienced mashers here think?

menshmaschine, you're a real mensch. That was exactly the sort of info I was looking for.

It's actually for a saison I'm doing this weekend with pilsner malt. I had programed things at a certain spot to get a higher attenuation on the sacch rest, but obviously, you kind of need to know where you're protein rest is to know how much water to infuse.

kmlavoy said:

It's actually for a saison I'm doing this weekend with pilsner malt. I had programed things at a certain spot to get a higher attenuation on the sacch rest, but obviously, you kind of need to know where you're protein rest is to know how much water to infuse.

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Cool. I've never brewed a saison, but from looking at the style, you're looking for a good head and high attenuation (~80%). Unless you have your malt analysis (then you can really dial in your temps), I would consider doing a protein/sacch. rest at 131dF, and a sacch. temp at the low to mid 150's. That should get you good attenuation, good head formation/retention and just enough body to be characteristic of the style. If you're infusing with hot water to reach your second rest temp., you'll want the initial rest to be a relatively thick mash and then infuse to a relatively thin mash. This should also aid in attenuation.

I'm really looking forward to it.

My plan was to do the sacch rest at 147ish. The grain bill is 9 pounds of Belgian Pilsner with 1 pound of Acidulated malt. I'm going to do a decoction mash out to try and darken it slightly.

It should be a fun time. Anything that ends in beer is fun.

i've brewed a few saisons, had some issues with attenuation, but am finally getting it down. consider one of the modern "watermarks" of the style: brasserie dupont does a gradual rise infusion mash from 113 deg f to 162 over the course of about two hours to achieve their 93% attenuation. others use a classic step infusion with rests at 113, 131, 144, and 154, mashing out at 165 (according to phil markowski in "farmhouse ales"). personally, i think you can skip the acid rest by using 5.2 buffer and protein rest too. do the sac rest then dextrine rest and mash out. your decoction should work for this.
also, if you're using a yeast like white labs 565, don't be afraid to let the primary temperature go. it's common to start out in the low 70's and let it go into the high 80's to get the most out of it. be patient, it's not unlikely for it to take from 10 to 14 days in primary and another few weeks in secondary.