Infused Svedka vodka with rosemary - 750mL plus 2 sprigs in an airtight container. We probably should have let it go for 2 days ... we let it go for 3 instead. At 12 hours, it tasted like vodka with a hint of ... something? At 24, you could start to taste something floral and earthy, but not really "rosemary." At 48, the herbal quality was improved, and at 72, you could start to pick up the twigginess of the rosemary sprigs. As it turns out, in cocktails, the twigginess isn't such a good thing.
But we did make a great cocktail out of it ... 1 part vodka, 1/2 part fresh lemon juice, 1/2 part fresh orange juice, and simple sugar to taste (I didn't want a "too-sweet cocktail," hence the herbal infusion). With a sliced orange round to garnish, it was perfect and got great reviews. A "taster" suggested using lillet blanc instead of the juices, but maybe he was just a lush who needed a higher proof on the thing ... although in sober retrospect, that actually sounds nice.
When I do this infusion again (and I WILL do it again!!), I will probably let it go just 48-56 hours.