London Mild Ale (1871) OG 1070, from the Durden Park book.
7.65 KG Pale Malt (3KG Muntons Maris Otter from Hogs Back Brewery, balance is Warminster from Farnborough HBS)
120g Fuggles from Hogs Back brewery - one addition, start of boil (after the foamy stuff has died down)
Yeast - Hook Norton Strain as slurry, from Hogs Back
Liquor prepared as 'London' water. CRS & NaCl, no DLS.
Following DP method, mashed for 3 hrs, 67c-64c. raised mash to 75c (couldn't get enough liquor in the tun to get to 77c - 75c is good enough) and left for another 1/2 hr.....
Then the fun started. The mother of set mashes. Even before running off I could see the grain was compacted well down and sure enough after about 6L run off, it stopped. Underletting raised the bed, but didn't cure it. Run off started again, but all it was was the underlet liquor I put in! When that had gone, it stuck again. The bed wasn't letting anything through either way. Did this three times before I thought..go for broke. Stirred the mash, and underlet while stirring. This broke up the compacted grain, which then behaved as normal. Fly sparged from that point to keep the bed loose. Ended up collecting loads because so much of the runnings was undelet liquor that hadn't picked up any sugar. Stopped at 1050 and 37L, preboil. Gravity of last runnings - G1017
Boiled 90 mins, used protofloc. WOW! What a difference! Hot break central

Yeast meanwhile had been kindly given some wort I'd prepared earlier (and frozen) and repaid me by trying to escape the milk bottle. Damn cheek.
Anyway, I topped up to 24L and got OG 1073.5, adjusted to OG1070 by losing some trub infested wort, and replacing with liquor. Aerated with sloshing, spraying, and foaming, for ages. Added Yeast vit, and bunged in the yeast.
Extraction efficiency 80%, brewhouse efficiency 77%
2.5 hrs after pitching and there's 2" of cold break on the bottom andthe yeast is starting to do stuff.
Today had almost everything. Mash drama, All 3 sorts of liquid on the floor - water, wort, & steriliser, procedural cockups, etc...but no breakages

( I too always thought hot break was the coagulation towards the end of the boil. As in...add irish moss to assist with the hot break. Or, boil until the hot break is achieved)