I have some coffee cold brewing in my fridge right now that I'm going to be adding to my fermenter later this week. I've read a few instances online where people suffered infections in their beer by adding cold-brewed coffee to their beers. In order to avoid this, I'd like to figure out a way to sterilize the coffee before adding it. I know I could probably heat it up to 160 before adding to the fermenter, but I'm not sure whether this would diminish any of the coffee flavors, which would defeat the purpose of cold-brewing to begin with. What about adding a piece of a crushed campden tablet to the coffee? Other thoughts?
I regularely blend cold brewed coffee with a milk stout and have yet to see an infection. I have brewed this beer about 30 times in the past 2 years. It is usually conumsed in about 4 weeks and stored cold, so lacto could be present and may not have time to really develop, but I wouldnt be too worried if I was you.
I don't see how there could possibly be infection sources from the coffee. The acidity of the coffee + adding it to a finished beer that is both alcohol content and low ph.
Make your cold brew and simply add. I have used coffee in a lot of beers and have never had an infection issue. Some of those beers have lasted 3 months in the keg with zero ill effects. I say be clean just like always and pitch the cold brew at kegging. I will add that I have always sanitized my container that I'm making my cold brew in prior to making the cold brew. Hope that helps put your worries at ease.
You just made me think that when I do this I'll be adding a touch of campden tablet to the coffee. I'd brew with tap water and that means chloramines. This is also a common way to prevent bacteral growth for many vintners, since they don't do 60 min boils. Prost!
Coffee from a sealed bag should be sanitary. Boil and cool the water before making the cold brew. There should be no problems. If you're worried you can pasteurize as low as 140F (but you will need 20 minutes at that temp).
The one and only time I added cold.pressed coffee I wound up with an infection. I either dry bean or use an extract, home made of course.
If your worried about infection with cold press, just sanitize your press, use fresh beans, and distilled water out of a fresh gallon and cover up the spout with al foil.
I ended up just bringing it up to 160 degrees before adding to the fermenter. I guess I'd rather risk a slightly diminished coffee flavor over a spoiled 5-gallon batch. Thanks for all the input.
