I'm brewing into small, split batches lately to test the effects of various additives. I've got some true cinnamon bark and cacao nibs which I am planning on crushing up, letting steep in alcohol (upper-shelf vodka) for a couple of weeks, and then pitching into 1gal batches of stout when I rack them into secondary.
Since I'm adding these tinctures/flavorings into such small (1gal) batches of beer, I don't want to end up adding too much of the alcohol sanitizing/tincturing agent and messing up the beer. I'm hoping to dilute the alcohol with some water, so that there's enough to immerse (and thus sanitize and start infusing) the crushed-up flavorings without making my beer taste too much like vodka. What is the minimum safe solution of alcohol:water that will still result in
- a good, flavor-rich infusion, and
- a bacteria-free addition to secondary?
The first point is less important: I can prolong the infusing process for months to get the proper flavor levels if need be, so long as the end product is sanitized.