I’m still fairly new at this, since this question is about my third batch. Well, I decided I know everything there is to know about zymurgy and charged forth with my own wacky recipe, a cranberry dunkelweizen. After a bit of light reading I decided the best way to cran the crap out of this beer was to put mashed cranberries in the secondary with a teaspoon of bloomed gelatin to knock down the haze. Problem is, I check it the next day and I’ve got beer dribbling out of the airlock. Where did I go wrong?
not enough headspace.
while the sugar content of cranberries is low it isn’t zero. when you introduced them to the yeast there was a secondary fermentation.
Also, gelatin is a fining used after all fermentation is complete to remove stubborn yeast and some proteins. if you cooked the cranberries you would want to add pectic enzyme to knock out the pectin haze that the cranberries will leave. However in a weizen haze isn’t an issue, lack of haze is so don’t do that.
pull the airlock, replace temporarily with sanitized foil or plastic wrap, clean well and replace. if it’s still blowing lots of foam you could put a blow off rig on for a few days instead of replacing the airlock