I want to brew an oatmeal stout and add rye whiskey w/ oak to secondary. Any thoughts on how much? I'm not looking for punch you in the face levels but enough to know its there. Thanks.
Soak 3 oz of medium or medium plus toast oak cubes in about 4 oz of whiskey for at least 3 weeks. Add the cubes in secondary, filter the whiskey they were in through a coffee filter (to remove the carbon dust), and add it as well. That should give you a nice whiskey backbone. This is for a 5 gal batch.
I brewed an oaked rye/oat stout that came out very nice. My approach was to brew the stout and add the oak cubes to fermenter after initial fermentation. I didn't boil the cubes or soak them in anything. After 2 weeks on oak, I bottled 1/2 the batch. The other half batch kept oaking another couple of weeks, and I added bourbon at bottling to taste (approximately 2oz per gallon).
Some people don't do anything to sanitize the oak and have no problem. Some say that soaking in bourbon isn't even sufficient, but I didn't have a problem when I did it. When you use oak cubes, you want to leave the beer on them for at least 8 weeks, as it takes some time to penetrate all of the layers and maximize complexity. For oak chips, 1-2 weeks is all that is necessary.