No I'm not a Guinness drinker....but I found the link... hope it helps you...a Sour Mash to me is "moonshine"....but I can see from the link that it was added to give that "bit extra"
Thanks Dieseljockey. Have also read somewhere that you can use a
pint of guinness let it sour over a week and add to the boil
which might be easier not sure if better though.
I was hoping someone had tried. guess ill have to
find out for myself .
cheers
Ric