I'm glad you asked this question, I am currently trying to remember if I carbed a Blackberry Ale I bottled about a month ago. This brew still has no carbonation, and I could swear I added priming sugar, however, I have never had a brew take more than 3 weeks to carb up. I know some beers can take longer, but it is a moderate 6% ABV, and my last Blackberry Ale carbed up within the 3 weeks, having said that, I did use Oregon fruit for this batch and fresh fruit for the last.