Originally Posted by oboelestoe
I'm planning on substituting a little brown sugar for some of the priming sugar. Maybe 50/50. Does this sound like a good idea or... not so much? Should I wait until I have one under my belt before I start monkeying around with the ingredients? Or is that small substitution relatively safe?
I've never tried this, but from what I've read in several places, I would gently advise against it at this point. Mostly because it's additional complexity, and getting priming quantities right is important. For the first (or first-and-a-halfth) time around, I think it would be wise to stick to the simplest procedures from here on. There's a lot to think about on your first bottling day. Also, the flavor effect is going to be subtle, so there's not a big return on your "investment." I imagine you could get a similar effect by adding a bit of molasses to your beer near the end of fermentation (after boiling it in a small amount of water for a few minutes to deoxygenate and sanitize it)---that would not require compensation at priming time.
However, plenty of people use all kinds of different sugars successfully. (Here's one random thread, there are many others: http://www.homebrewtalk.com/f35/priming-brown-sugar-61921/
) There can be a subtle effect on the flavor, and it might go well in an oatmeal stout, so you do have a beer that's more amenable to the experiment than most.
If you do go that route, bear in mind that you need to adjust your priming sugar quantity depending on the type of sugar you use. I can't find a specific number for brown sugar, but it's basically cane sugar with molasses added, so the rule of thumb seems to be to treat it like cane sugar. This produces more carbonation per weight than corn sugar (dextrose), so don't just replace half the weight of your corn sugar with brown sugar!