So easy. Just take some decent quality vodka and soak stuff in it. Walla.
For something delicate like berries, I would probably just do a couple of days. I recently did bacon and green chile, and left that in for a week. I could have gone longer, but I was impatient.
Then you just strain and put it back in the bottle. I keep it in the fridge, just in case. I don't think anything can grow in 80 proof vodka, but better safe than sorry.
I made cherry, strawberry and raspberry vodkas last summer. They were so good.
Now I want to make blackberry vodka along with some green chile and bacon vodka. I am going to assume you cooked the bacon until crisp and crumbled it in the bottle?
Blackberry sounds good. Blueberry might be more versatile? Idk, I'd think you could get the essence of the sage from just mixing it in a single drink, that way you aren't stuck with it if you don't like the taste.