German Brewing

Reading the Quest for Edelstoff blog a came across a Protein Rest chart (sourced fro Hanghover) which bases wether or not a Protein rest is needed as well as desired rest temp and time based off of the Kolbach/SNR ratio:

< 35%: 50C for 30m
35-38%: 54C for 20
38-41%: 57C for 10

Is this a solid rule to follow or are their other factors I should consider that would change this advice?

I will let the man who created it chime in, however, I would only consider one of them a "protein" rest

These are basically dough-in temperatures for malts with different levels of modification. It also depends on how you mash the grain. If you decoct, then you end up with a whole new set of starches to convert after the boil. All this has an impact.

This table is by no means the definitive guide, but for infusion mashes it's a very good guideline, so I put it on my blog to remind myself when needed. For the well modified malts from Best or Wey for eg, it doesn't hurt to dough in at 58C and then to the target temp. I'd avoid long rests at 50C with those malts.

For wheat beers it's very different though. Usually it's mash in at 35C 15", then to 45C 20", then 50C 20" then proceed as usual (unless you want to do a maltose mash). Wheat malts contain way more proteins than barley malt, so a decent length protein rest is important.

Most of the modern malts are intended to do away with the protein rest, as well as requiring less intense mashing schedules. Once I understood this I pretty quickly changed from a double decoction to a single decoction schedule and am very happy with it

I did a dough in around 100F and recirc'd up to ~158F via direct heating my keggle. This was the resultant protein coagulant that I strain from my boil to prevent draining issues down the line. I'm sure if I hadn't it would have been near impossible to take advantage of the whirlpool.

Note this was a Pilsner:

Belgian - Pilsner 37 1.6 88.9%
German - CaraFoam 37 1.8 3.2%
German - CaraHell 34 11 3.2%
German - Acidulated Malt 27 3.4 3.2%
German - Melanoidin 37 25 1.6%

It was the most fantastic egg drop soup effect up until it all started clumping together.