My brew day with a stout

[wetzie]

Oatmeal Stout
This post is to solicit some thoughts on what I should improve. I was going for a medium beer with a smooth oatmeal flavor with a heavier body. I am not sure where I got the recipe but brewed this in the past with decent results.
Ingredients: 10lbs 2 Row, 1.50 lb Quick Flaked Oats; 1.0 lb Caramel/Crystal Malt Dark, 0.66 lb Chocolate Malt, 0.55 lb Cara-Pils, 0.44 lb Roasted Malt, 1.5 oz Warrior (60 min); .5oz Warrior (15 min); Irish Moss (15 min)
The 2 row was bought 8 months ago in a sack and stored in homer buckets (I crush my own) (MM2); the specialty grains were bought today; the hops were purchased last year and frozen immediately, defrosted today.
Ph 6.0 before (10 min in) specialty grains were added (ph strips are two years old) We use well water but a Ward water report showed neutral water.
Mash started at 155f but in 20 min dropped to 150f at 20min. Used a 10 gallon round Coleman cooler. I preheated the cooler but the temperature dropped for some reason.
At 20 min added boiling water to bring to 155f
At 35min added dark roast barley and other specialty grains and ingredients for late addition.
Started batch sparge at 160f but about halfway through dropped to 144f. Did two batch sparges with 170f water. I would guess the temperature could lack accuracy due to mash stir but I gave it a pretty good shot.
Preboil yielded 8.0 gallons at 1.044. This put me at 70% efficiency but I usually get high seventies. When I added the boiling water at 20 min the additional wort volume was not realized until the end.
Thank you for looking and if you have any suggestions it would be very welcomed.

 

[whatsleftofyou]

There are too many variables here to give you solid advice. It seems like for some reason your MLT doesn't insulate very well and your temps are all over the place. Is that normal, or just with this batch?

 

[beerme70]

I am by no means an expert, but I can only think of a couple of things. When I preheat my MLT, I usually take my water to around 190 and let it sit in the MLT for about 15-20 minutes. Then, I will open the lid and let the water cool to my strike temp, then immediately add my grains, stir, and close as quickly as possible. You had a grain addition 35 minutes or so into your rest....that would lower the temp of your mash as well, but if it's a pound or so, I don't think that would throw the mash temp off enough to matter. I usually mash-out at 168*, rest for 10 minutes, vorlauf about a gallon or so, then let it run out. Then I'll batch sparge with roughly 2-3 gallons of water at 168*, and again vorlauf, and let that run. Not a lot of time to allow the temps to drop.

 

[Rev2010]

As mentioned, the late addition could drop the temp, but how much depends on the quantity of grains added - on my phone so I didn't check your recipe. Also your batch sparge water needs to be hotter. You want to get the temp UP to 168-170 so you need hotter water, you can use an infusion calc to figure out what temp it should be. Reason is to lower the wort viscosity and provide a better rinse, so to speak.


Rev.

 

[wetzie]

I appreciate the comments, I do play it too loose with the sparge water temp.
I made sure to stir the mash a lot to get a good temperature reading overall ( I use a Thermopen).
I like the idea of letting the mash water set in the mash tun for preheating.
Thank you all

 

[wetzie]

I figured out what I was doing wrong with the temps. I was using the amount of late addition grains in my calculations!
My mash temps were good and then I would 3-4lbs of specialty grains and then chase my temp goal with the rest of the mash. Fixed on a recent brew and the temps held fine.
Thanx all