Decoction step mash help

The equipment I have for now is a 22 qt kettle and a 10 gal round cooler MLT with braid. I do PM batches and add whatever DME & water for the volume and ABV I want.

The amount of grain I can use (7.5 lbs) is determined by the amount of sparge water that will fit in the kettle, which I keep at 1 qt/lb for 2 equal batch sparges after mashing at 1.25 qt/lb. For 7.5 lbs, this usually gives me 1.5 for first runnings, then I do 2 batch sparges just shy of 2 gallons each where the first raises the grain to 170. This procedure gets me 76% everytime.

Up till now, I've only done ales. The next recipe I'd like to try is a pilsner so I'd also like to try a protein rest.

Can/should I do this?:
-infuse 1.25 qt/lb, 122F rest for 20 min.
-vorlauf and collect 1 gallon
-boil 1 gallon and add back to mash to raise temp to 153
-hold for 60 min.
-batch sparge as normal

I'm a bit confused by your mashing schedule..

Are you boiling only the liquid post-volauf, or are you removing part the 1/3rd thickest part of the mash (grains and all!) and bringing that to a boil?



Awfers

I'm new to decocting as well, in fact I haven't done one yet (next brew)but to my understanding you boil some of the grains with some of the runnings. Watch Kaiser's video series on it, it's very informative and only takes like 10mins.

I may be wrong in the above, but I know when I do my first decoction, it's going to be step by step as per Jamil Z, as I wrote down some notes when I listened to a broadcast on it.

"Are you boiling only the liquid post-volauf"

Yes

I don't want to do a real decoction like kaiser. I just want to be able to heat from 122 to 158 without adding another infusion of new water. I'd like to take pre-runnings (I suppose you could say) after the 122F rest and boil them to then add back in order to raise to 158.

Well, a couple of things come to mind for me. If you boil the runnings, you end the enzyme activity, so when you add it back, you're raising the temperature, but it won't be effective for the wort you boiled.

Another thought- why don't you mash thicker for your protein rest, then add water to bring you up to 1.5 quarts per pound for your saccrification rest?

I'm not real familiar with PM brewing, though, so I'm not able to think through this any further.

YooperBrew has it right, you don't want to do a thin decoction to raise from protein to conversion rest. Even if you do a conversion rest of the decoction (as you should) you still won't have enough enzymes in the main mash to fully convert.

If you're not willing to take the time to do a proper decoction boil to raise the temperature you will want to either directly heat the entire mash up to the next step (not possible in your case) or do the protein rest thick and infuse enough hot water to raise the mash up to conversion.

Your last option is to just skip the protein rest, modern pilsner malt doesn't require it.

Ok, thanks all for the advice.
I'm going to stick with a boring single infusion at ~153. If I mash thick at 122, the amount of boiling water needed to raise to 153 takes away too much from the sparge water I'll need at the end.

I wouldn't recommend the 20 min rest at 122 for 20 min. Todays malts don't need that anymore. Here are a few nice step/decoction mashing options for a Pilsner. All mashes target a thickness of about 1.75 - 2 qt/lb (3-4 l/kg):

my standard mash:
dough in at 56-59C hold for 15 min.
infuse with boiling water to 65C hold for 45 min
decoct to 76C for mash-out.

You can also skip the dough in rest and infuse to 65C, but I like what it does to the enzymes and that I'm able to approach my sacc rest temp through water infusions. this allows me to stop when it is reached.

Hochkurz double decoction:
dough in at 63C hold for 30 min
decoct to 70C and hold for 30 min.
decoct to 76C for mash out.

In this mash the decoctions don't have to be thick. Just stirring up the mash and pulling the desired volume should be fine. The reason for that is that they are small to begin with (only small temp increase is needed) and pilsner malt is very enzyme rich.

Kai