Many of the recipes I’ve been looking at, even in fairly recent publications call for a 120 degree rest before boosting to starch conversion temps. The first time I got into brewing thirty-some years ago protein rests were necessary with American malts because they weren’t fully modified, my understanding is that now even American 6 row is well modified and doesn’t need the protein rest. Is my understanding incorrect or is there another reason for the 120 degree step?
The reason I ask is that after mashing a few batches in the BK I have switched to using a cooler and a brewbag, which I greatly prefer. Unfortunately trying to guess how much water at what temp to add to boost from 120 to starch conversion temps in a stepped mash is a sumbuck.
Which leads to the second part of the question, is there information comprehensible to a neanderthal such as myself, that would enable me to calculate the mass of water at what temp is necessary to boost the temp of a known mass of grain and water at a given mean temperature to boost the whole shebang to a specified temp? If it was just a matter of combining 2 known masses of water at different know temps it would be pretty easy to figure out the mixed temp, but for reasons I haven’t figured out yet it doesn’t work out with grain as part of the mass.
On a different note, FWIW, I stumbled last night upon a couple bombers of stout I made at least 31 years ago, the records of it’s creation have long since disappeared but I am certain it was an AG batch, probably my first one. Amazingly it didn’t taste half bad, in fact it tastes much better than I remember any of those early attempts turning out. I would never have believed that something as fragile as beer could remain unchanged for as long as that stout did. Now the other stuff I found with it is good only for cooking beans.
I use beersmith brewing software for my brews and it calculates this for me. I believe brewersfriend.com has a calculator on it that will calculate those temps for you. As for the protein rest, I have done nothing but single infusion mashes for the whole of my brewing career (3 years plus a month ) so I have no opininon on the protein rest except that I regularly read on this forum that it unnecessary and potentially causes problems like poor head retention with today’s fully modified grains. More will chime in with more info, of that I am sure
Wow, you have beer from 31 years ago and it’s not terrible!? That’s cool is heck!
Protein rests should no longer be used because every commercial malt is well modified now, and a protein rest of about 120 F will kill your body and head retention. I know this from personal experience as well as the experiences of others.
If you purposely try to find an undermodified malt on the market, you can’t even find any. Even the ones where people say “oh this floor malted barley is undermodified” yadda yadda, if you look at the actual specifications, it’s fully modified and will be damaged by a protein rest. It’s best to skip it and only do single infusion mashes these days, unless you want to do decoctions for fun, but even then, it is wise to totally avoid the 120 F area, and just go right up to the 140s and 150s.
Kind of what I suspected. Why do so many recipes in well known books that I’m assuming were written after the current malts replaced the old under modified ones, still include protein rests in so many recipes? Perhaps that’s a rhetorical question.
And yes the stout is not only drinkable, but is better than some of the stuff I’ve paid money for. I wish I had a few more bottles to share with others.
I don’t know what books you are referencing, but I rarely see recipes that call for anything other than a single infusion mash.
The general populous is only learning now that protein rests are detrimental with 21st century malts. A few people knew this 10 years ago but it takes a very long time before everyone knows about it. Only now in the past year or two really are people really figuring this out, and there are still thousands of people who will swear you need a protein rest until they try it and end up with thin, watery, lifeless beer.
What books are you referring to?
Clone Brews has a number of recipes which call for protein rests, I was thinking that Classic Styles also had some but after re-checking theirs are all single step infusion mashes, the rest of the books which include protein rests are early to mid 90’s or older. There are a number of recipes on the AHA website which includes rests in the protein temperature range? The ones I found are all decoction mashes, but I would think a protein rest is a protein rest, regardless of mashing style.
How long has it been since under modified malts were available on the homebrew market?
I think BCS calls for a protein rest in the Wit recipe.
IMO, Clone Brews is about the worst homebrew book ever written. It’s been 12 years or more since you didn’t have to go out of your way to find malts that required a protein rest. As the commercial beer market got bigger and bigger, commercial brewers didn’t want to mess with it, so the malts became more highly modified.
Yeah, it’s bad. I brewed a couple of those recipes to the T, and then tossed the book.
When I saw that the Duvel recipe included pear extract, I gave up.
Yeah, just lame. If you ferment it right you get that from the yeast. 
I have done multistep mashing for the majority of my AG batches and have not noticed any adverse effects from the grains. Why would a rest at 120F damage the malts? dmtaylor, dennyC, Hoosierbrew? Randys book, Mastering Homebrew, talks about theses rests in detail. Why they are necessary, even with todays malts. If only I could put my thumb on the page & paragraph…
A 120 rest with highly modified malt can ruin the body and foam of a beer. Plus, as far as I can tell, you’re not actually improving anything.
From page 122 or so (using a Kindle so I can’t tell exactly):
He does go on to explain some of these things (including a lot of decoction examples that start at lower temps), but the warning is clear.
Nice find. Nowadays I err on the side of no protein rest.
Sweet reference. I have the utmost respect for Mr. Mosher, he’s one of the very few “celebrities” (besides Denny) who really seems to “get it”. I’ll confess I have purchased Mastering Homebrew with the intent of reading it soon, as it looks like a phenomenal and super detailed book… but I’m not as much a reader these days as I once was (damned worthless Facebook is such an evil and wasteful distraction!), so this book that I’m sure is excellent still sits on my huge pile of things I’ve yet to read.
FYI — WLP400 witbier yeast throws a lot of pear ester. I’ll bet it would be wonderful in a Duvel clone.
IMO too phenolic. Duvel is vert clean other than the slightest bit of fruit.