Brewing with chocolate has been a research project of mine for a couple months. One of my boys who just got his four-year degree was discussing which off-the-shelf chocolate would be best for certain applications.
His major is in food science and he has a background in producing brand-name commercial chocolates for Godiva, so when I brought chocolate up for porters and stouts, he had quite a few suggestions on what to avoid.
My brewing setup isn't typical of most others, so the choice and application of adjunct flavorings will be different.
His suggestion led me to choose an unsweetened processed chocolate because the natural cocoa butter is removed. During the boil, precipitated oils can interfere with hop-protein interaction influencing the beer's foam potential. I love foam so that's a big factor. Founders Porter is one of my favorites, but it has very little in the way of persistent foam.
Second, I didn't want a collection of cocoa butter and hop oils to affect hop utilization and gunk up my beautiful steel boil kettle. Cleaning it is already a major pain in the arse.
My choice? Ghirardelli dark unsweetened cocoa powder, added to primary or to a secondary fermentation just after high krausen has started to subside. I like that brand and it has less sodium by weight than the Hershey's Special Dark by comparison. On bottling, a small addition of vanilla extract can be added to the mixing bucket. Four to eight weeks of bottle conditioning should be fine in my case as the porter/stout won't be a high gravity batch.
I like cheap, but I also like efficiency. Raw cocoa and vanilla adds an expense factor that can be removed from my process.
