Hi, thanks for the info and very sorry to post something that's not allowed. I looked on the forum rules prior to posting and it wasn't explosive or drug-related, (well, I guess technically alcohol's a drug but this is for a NON-alcoholic product).
Actually, I've been using the Cook's Illustrated method for eggnog for several years, that exact recipe, and that's what prompted me to try to find out the answer to this question. I'm fine with 30% if that's what it takes, but the "citizen scientist" in me is just curious about where and when that line gets drawn. Especially since sugar itself is a preservative, whereas eggs are a host and possibly already contaminated.
Perhaps someone can just answer the math question side: For an 8oz quantity of non-alcohol liquid (i.e. syrup), what quantity of 95% pure alcohol would I need to add to get the liquid to a 30% ABV?
Anyway, again, sorry to post a non-allowed question. I'm a bit disappointed though, as this seems like just the kind of interesting info the web and its hive-mind are able to provide and I feel like the legal risk is pretty minimal. Perhaps if anyone out there wants to answer it directly they could PM me and we can discuss it out of the public eye? I can PM my email or something so it's not even discussed directly on the forum at all.
Again, thank you for taking the time to explain and I'll keep fingers crossed that someone out there can add some useful info without opening up the site for a lawsuit.