Source: Bob Wysong (firstname.lastname@example.org), HBD Issue #2015, 4/19/96
Put in insulated box for 2 1/2 hours. Ending temp was 145. The requirement was for two hours, but getting the sparge water ready took longer than I wanted. Then I boosted to 168 degrees for mash-out. (iodine test showed complete conversion).
For the sparge water, I used an 8% Phosporic acid solution to acidify 6 gallons of hot tap water. After 2 tsps, my PH strips looked like they were still above 6.0. Then, on the 3rd teaspoon, the PH abruptly changed, and the test strips remained yellow, indicating that it was now very acidic. I had to add about 3 more gallons of water before it got back up to about 5.0.
I was expecting just a slow trickle for the sparge, but once I opened the spigot on my lauter tun, the wort hissed out. (Used the cylindrical cooler with sparge bag on SS vegetable strainer) It never did slow to a trickle as I was expecting. I slowed the flow of the output and input so that the sparge would take about an hour. (The water was 168 degrees, Re-circulated 1st runnings until clear) NOTE: I don't think the water was leaking thru the sides of the sparge bag, and it looked like it *was* filtering through the grain bed OK, which was always held in suspension.
Collected about 8 gallons of wort (ph of the runnings never dropped below 5.8 even though the gravity dropped to about 1.010) and boiled for 90 minutes. A gravity reading before the boil showed only about 1.020 (granted, it was 8 gallons) prompting me to add 1 lb DME. I thought I had boiled down to 5 gallons, but was actually 6. (Haven't put any sort of volume markings in my Sankey keg boiler yet). Used a CF chiller, shook the 6 1/2 gal car-boy for about 5 minutes to oxygenate and pitched yeast. FG was only 1.032 at 60 deg F.
No activity for 24 hours. After about 2 days, the krausen remained only about 2 inches (My weakest ferment ever). Since my first "mostly-grain" batch had a tremendous amount of gray gunk floating on top of the foam, I definitely wanted it to blow out of my car-boy which had about 6 inches of head space. So I added about 1 tsp *each* of Yeast nutrient, Yeast energizer, and Amylase enzyme to 180 degree water and then dumped it in. Also, I swirled the contents around in the carboy hoping to get the yeast more active. BTW, I have no idea what the nutrient and energizer consist of.