Back to Shopping at

I have a complex protein rest/ mash temp question

Or maybe I’m making it more complex then it needs to be. My question is this…
what is the harm/ help/ whatever of adding more time between the protein rest and the mash?
Our system takes a while to get from 122 to 155, am I doing damage to the proteins/ fermentables in the time it takes to reach mash, from protein rest?
We recirculate our mash through a coil in the HLT then back over the grain bed, it’s not a super effecient system, and I’m worried that the 45 (ish) minutes that it takes to get the grain up to mash temp will have negative effects.
Or am I making a big deal outta nothing?

As always, any input is appreciated!

Reduces body and head retention.

+1 head retention, if your beer is coming out good then I wouldn’t worry about it. As soon as you get to a temp that denatures proteinases you a OK anyway, and the Beta amylase starts working well before you hit 152F. If you’re satisfied with the body and head retention then what you’re doing is fine.

If you’re set on doing a protein rest (which I consider unnecessary 99% of the time) you might try it at 131 instead of 122. You’ll have a faster ramp time to your sacc rest and you’ll do less damage at 131 than 122.

I agree with Denny and the others that 99% of the time you will do more harm than good with any protein rest. As stated if you feel its warranted 131>is sound advice.

70% of today’s malts are considered well modified and contain low protein levels.
If you employ a protein rest you start to create extra low mouthfeel/ body and affect head/ foam
25% of todays malts are considered overmodified and the mash should actually be adjusted to add more dextrins as the beer produced with extreme overmodified malt will be thin in body naturally if only rested within 140-150(ish).

5% > The only time to employ protein rests is if using undermodified malt which is very rare unless you seek it out. With large % of grist containing six row malts, rye, oats or other containing high protein levels or when using high percentages of adjunct like rice, corn etc… in the grist. Or large amounts of sugars in the wort boil as you want to increase the FAN levels then as the adjuncts dilute the FAN pool.

By employing protein rests with well-over modified malts other than creating poor body and low foam positive factors. You potentially create an excess of FAN with normal well-overmodified malts. Which we know low FAN is suboptimal and will see yeast stressed thus creating excess higher alcohols or long lag times etc…, midrange levels created by normal Sacc rests alone is perfect in today’s malts, whereas high-extreme levels of FAN can actually help the yeast to create excess diacetyl and other higher alcohols/ Fusels the same as if they had low FAN.

Great post! ^^^^^


that’s all I can say! That answers all of my questions and trouble shoots half the problems I’ve been having! WOW!


Another opinion is to treat the 131 like a dough-in rather than a protein rest. I find dumping the grain in and stabilizing in the low 130’s eliminates any dough balls and makes the mash more liquid from the start.

After stirring in I raise up to my temps. Probably in the 130s for five to ten minutes then up it goes.

So many opinoins on this. I have heard that an upper protein rest actually helps with foam, even with today’s malts. Dan Gordon as a guest on the Brewing Network talks about his mash schedules and they are full of all kinds of rests using Weyermann malts.

This would be a good topic for Brewing TV to do a side by side. Same everything except the protein rest.

When I look at all the protein that drops out of a mash, especially with pils malts, I find it hard to imagine that a protein rest is going to do any great harm. Proteinases aren’t specific to certain proteins and it would seem that just by mass action you’d protect a big percentage of those proteins involved with head retention. I’ve done protein rests and not seen a negative effect, although I can’t say I’ve seen a positive effect either. I’m the first one to admit that some of the stuff I do, is just for the fun of doing things the traditional way.

Lennie, I’ve screwed up more beers than I care to think about doing a protein rest. I’ve also done back to back batches of the same recipe, using the same bags of grain, with and without a protein rest. I’ve never found that it makes a better beer. YMMV.

What does “FAN” mean?

free amino nitrogen = FAN

I guess I haven’t noticed anything getting screwed up, but I don’t tend to analyze my results all that closely.

Back to Shopping at