Decoction help?

I’d like to make this beer - Jeff's Untitled Dortmunder - Beer Recipe - American Homebrewers Association.

In the directions it states “Mash with 1.5 quarts of water per pound of grain. Use a decoction schedule, pulling a 30-minute decoction with half of the Pilsner malt while the main mash rests at 130° F (54° C). Boil the decoction and return it to the main mash to raise the temperature to 149° F (65° C), and hold for 90 minutes”.

I think the “half the Pilsner” is what threw me. I thought that I would mash the entire grist, pull a portion after protein rest, boil it and return it to mash in order to push the temp to the 149. Can someone give me their step by step interpretation of these directions? Thanks!

A protein rest for 30 minutes is a really bad idea in the 21st century.  Don’t do it.

90 minutes at 149 F is also extreme overkill.

Make life easier and more effective.  See my method here:

https://www.homebrewersassociation.org/forum/index.php?topic=24627.msg328634#msg328634

By the way… I still haven’t followed this exact method yet, but based on past similar experience, I know this tweaked process will work.  And I will in fact use it for my Vienna/Oktoberfest in the next week or two.  Fun.

I believe your interpretation of the directions is correct.  “Half the pilsner malt” means the portion of the mash you pull for decoction should include half of the grains being mashed (and you would be mashing the entire grist).

You are correct in your interpretation. You would begin mashing all of your grains and water at 130. You would then pull approximately half of thickest portion of the mash back out to do a decoction.

Personally, I would hold the decoction portion at normal conversion temperature for at least 30 minutes prior to ramping up to a boil. It would let the enzymes in the decoction convert the starches before denaturing.

Others might have different opinions, but that is what I would do.