So, I guess I had forgotten what making a big beer looks like.
In the end, the one pouch of Imperial, with a 2 liter starter (almost) seems like plenty when this fresh
The brew day went very well, shot for 60% efficiency, based on prior experience and no sparge.
Wound up with initial Tilt and standard hydrometer readings of 1.102 versus the 1.085 I was targeting, so actually ran right around 73%.
Made the 2 liter starter about 2 hours into brew day, as I had forgotten about it at the start of the day. Then continued the brew. At one point, I had 3 burners going, with the main batch, the first gallon being reduced, and the second runnings for a small Scottish (capped the mash with 3# Golden Promise and another 2oz Roasted Barley, OG of 1.043). Really kept me on my toes for a couple hours there.
Once the boils were finished and chilled as much as I could with my Hydra, I placed both fermenters into my temp controlled chest freezer and waited for them to reach pitching temp of 64°. Not long after, I came down with the starter for the big batch, and gave it a swirl to get it moving. It gushed out of the gallon jug I had it in at the time. Lucking I was standing next to the freezer at the time and was able to get most of it into the fermenter. Signs of fermentation before bed on Sunday night, just about 6 hours after pitching.
I had been getting higher than expected temps from the Tilt in the Traquair batch, while the small Scottish was in line with the temp controller on the freezer. My temp sensor for the controller was taped to the Traquair batch and it was running about where I wanted it. I went to work as normal, and then last night I opened the freezer to figure out why the one Tilt was reading 3-4° higher than the other. So glad I checked, it had clogged the 3 piece airlock and blown it out of the fermenter. There was about 2 cups worth of yeast and wort pooled on top of the fermenter, and a large splash mark on the ceiling of the freezer, and probably another 2 cups worth sitting on the bottom of the freezer. The fermenter is 7.9 gallons, I put 5.75 gallons of wort plus the 2 liter starter (total right around 6 gallons) in there. Seemed like it should have been plenty of room to work...
So, now I remember what a blow off tube is ( so many well behaved lagers in the last 2 years.) I think I can also testify to the freshness and vitality of a 19 day old Imperial yeast pouch of Tartan. Thanx for all the suggestions and sorry I am not here as often as in the past. Brew happy my friends