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How to Protein rest

I about to brew a pilsner with a 55c (131) protein rest for 30 min. My question is on how an I best to raise the temp after the rest? I use a cooler for a M tun so direct heat is a no go.
Do I draw some wort off and heat up and add back to get to the 67c (152)
Or and I better to pump wort through my immersion chiller while it is in a pot of near boiling water.
There may also be other ways im not thinking of.

The first question you need to ask is WHY are you doing a protein rest? Back when malts were not fully modified, a protein rest resulted in more stable, better beer. These days, the malting company takes care of that for us. Unless you are planning to use old-fashioned intentionally undermodified malt. Weyermann has one of their pilsner malts processed that way, and last year I made a batch of pilsner using it. Can’t say I found it especially notable to drink, but it was fun to try the old method.

But to answer your initial question, any type of step mash in a cooler can be accomplished four ways that I can think of off the top of my head.

  1. Decoction. That’s the traditional method. Scoop out the thickest part of the mash (lots of grain included) and boil it for a few minutes, then add it back in. How much you take out determines what temperature difference you achieve. There are calculators to tell you how much mash to boil, but none of them work. So much is dependent on your specific system that it is trial and error until you get it down. Some claim that decoction results in maltier, better tasting beer, but that is debatable. What is definite and often overlooked is that decoction will raise your efficiency, often by a significant amount, so plan appropriately.

  2. Infusion. Start with a very thick mash, then add boiling water when you want to raise the temp. If you are trying to achieve more than two steps in a given mash, this can quickly become difficult as the volumes needed get progressively bigger with each step.

  3. Recirculating hot water through you IC could work, but you’ll have to stir the mash very well to get the temperature even. Never tried this myself, so I can’t give a personal perspective on it.

  4. Turbid mash. Very similar to decoction, except only the liquid portion is boiled, not the grain. Tends to result in lower fermentability and less clarity, so not something I’d recommend for a pilsner. It is generally only used for certain low-gravity brews because it will increase body.

I also use a cooler for a mash tun, and have found that decoction is the easiest for me when I’m step mashing - now that I know how much I need to fudge the calculations.

You can try it, as we all love to try it… but a protein rest is truly a waste of time and can even ruin a perfectly good beer. It will likely leave you with a very thin watery body and poor head retention. Just so you know.

What malt(s) are you using? What maltster?

If your recipe uses Chit Malt or malt specifically labeled “Under-modified” or “Floor Malted”, then a protein rest may benefit you.

These days “Floor Malted” is borderline as being classified under-modified.

A protein rest with under modified or moderately modified malts is one step to help achieve a maltier beer. You just have to ensure you’re using that type of malt.

The methods for raising temperature have already been mentioned but the one I tend to use is the thick initial mash along with an infusion of boiling water.

Doing a protein rest should depend on the particular malt you use, not a recipe. These days, there are almost no malts around that will benefit from a protein rest. On the rare occasions I want to do a step mash in a cooler, I simply stir in boiling water while I read the temp of the mash. When it gets to the temp I want, I stop adding water.

Thanks for all your comments. I have decided not to do a protein rest, but if I do in he future thanks for the different ways to do this.

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