This is my first attempt at sour mash so I'm kinda winging this as I go, doin' some experimenting to see which way I'll go with this in the future. This recipe is supposed to be the one used for George Dickel. I too mash in 5.5 gal volume so I'm using 8.4 lbs cracked corn, 0.8 lbs rye, and 0.8 lbs malted barley, doing two at a time for an 11 gal mash. I wasn't satisified with my results after the first so I up the malted barley to 1.6 lbs to get a better conversion. I also add enough sugar to get my SG up to 1.070 which amount to about 3 lbs. As I understand the main component making it sour mash is using backset from a previous distillation. It keeps your mash acidic and provides some continuity from batch to batch. I'm using about 1.5 gal of backset for each mash. I cook my corn at a slow simmer for about 15 minutes. Others cook longer (I've seen as much as 90 min) but I have found cooking beyond 15 min doesn't gain anything for me. I add the rye and then cool to 155F add a little alpha just to thin the mash a little and then thrown in the barley. At 85F I add the sugar, 1t gypsum, 5-6t yeast nutrient, and 5-6T Baker's Yeast that's been hydrating for at least one hour. (I've got 5 different yeasts and am just trying baker's this time). Ferment takes about 7 days. After seperating off the grain settling/clearing takes about 3-4 days.
Today I'm starting another mash and doing some more experimenting. I'm using 1/2 the grain from the previous mash, 4.2 lbs new cracked corn, 0.8 lbs rye, and 1.6 lbs malted barley. I put the new cracked corn in 2 gal water last night to pre-soak. Instead of pitching new yeast I'm going to use about 1/3 of the yeast bed left from the last mash.
I do my spirit runs using 50/50 low wines/wash. To this point I've done some stripping but haven't got to a spirit run so I can't make any assessment as to my final product. I have a couple of 1L barrels for some of this and I'll put the rest in glass w/oak strips.
I hope this is of some help for you. Beside all the likker I get what I like most about this hobby is the experimenting!
"Necessity is the plea for every infringement of human freedom. It is the argument of tyrants; it is the creed of slaves." William Pitt