Frozen grains cool the mash. Duh!

I brewed Orfy's Hobgoblin yesterday. I had a problem with my mash. I started with 3.5 gallons @ 165, added the grains, expecting to stir it down to 152, and the mash dropped to 138!

I had put the grains in the freezed because they had some bugs (not buying from that supplier again.) I completely forgot to take that into account when I started my brew day. So, I put freezing grains in my MLT, dropping my mash temp too low. Stupid!!

So, I removed 1/3 of the mash to the kettle and brought it up to as close to 170 as I dared, and then re-added it to the MLT, stirred and checked. I got 152 and it held for the full hour.

So, I'm not sure if this can be considered a decoction or not, but what are the implications of my screwup? Should I be okay? It's already blown off and made a mess, so I know it's fermenting well.

Yea, if you boiled that would be a decoction. No worries. Good thinking.

I don't think it is "technically" a decoction unless you actually boil the removed mash, but yeah, same principle. Supposedly, the process brings malt flavor to the forefront.

You didn't really have to worry about the 170 limit. The low mash PH protects against any concerns of releasing tannins etc.

You also came pretty darn close to a protein rest with the remainder. Depending on the grains in question, that may or may not have done anything.

Overall - just sounds like a good save to me.

I freeze my grains too to kill off any bugs, but I only leave them in for about a week, then take them out. You don't need to store the grains in the freezer.