Soured this stout by leaving four bottles of Guinness sitting out in an open vessel for 2.5 weeks.
Couple of suggestions I received in doing this from a brewmaster -
1: It may take more than a couple of days for that Guinness to get really sour. And you WANT it to be SO FREAK NASTY that you couldn't imagine putting in your body. Once it has reached that point, it is ready to be put in your beer.
2: Maybe try inoculating the sour sample with a few kernels of grain so that those lactobacillus cultures can get a good start. You want to make sure that it is lactic sour (like rotten milk), not acetic sour (like vinegar). If you just leave it to chance on the kitchen counter, you'll probably wind up with vinegar.
Ale yeast 2.00 unit, Yeast,
Soured Guinness Extra Stout 1.00 unit, Other, 4 guinness extra stouts soured for 2.5 weeks
- toasted oats at 300 until begin to brown
- steep grains and oats for 30 min at 155 in 1.5 quarts water
- bring to boil after removing grains and oats
- drop hops; boil 20 min
- add soured stout at 10 min
- remove from heat, follow Mr. B instructions
- ended up needing to add a quart of water at 10 min in boil... oatmeal took a LOT of the water out of play
- Not sure how to account for the soured stout in QBrew...