Hi, I just discovered a product called Cholaca (http://www.cholaca.com) . It is a pure liquid form of cacao and is being used by a dozen or so breweries to add chocolate flavor to stouts and porters. It’s said to impart better flavor and easier to use than cacao nibs. If anyone is using Cholaca, I’d like to know how much I should use in the secondary when brewing. Thanks.
If you don’t get a good answer here I’d suggest emailing the breweries listed on their page and asking what they do. At least one of those should reply with a response. Copper Kettle might be a good starting point, they are pretty open about their great beers.
I’m looking into this for a local home brew competition and just got off of the phone with Ira Leibtag the CEO of Cholaca. He mentioned that on average breweries that use Cholaca are using around 1 gallon per barrel…so around 4 ounces per gallon, but adjust according to taste or beer style.