First off, something is not right here if you’re using 11 lbs of grain in a 5 gallon batch and the beer tastes like blueberry water. No way. You would have to tell us what you were doing with the crush, the mash, the boil, the fermentation, etc. Let’s go like this… someone says to me, “please make me a blackberry wheat beer”. Here is what I would do. First, make a grain bill of about 50% domestic pale malt and 50% wheat (white wheat, red wheat, it’s all the same, generally). Make one hop addition at 60 minutes (which you did) and make it around 4.5% to 5% of a clean American ale hop like Mt. Hood, Liberty, Crystal, Vanguard, etc. Also, I would keep the beer around 5% so I’m guessing 4.5 lbs of pale malt, 4.5 lbs of wheat or maybe 5 lbs of each, whatever. Make sure that the beer ferments low (like 60-65°) with an American ale yeast like 1056 or WLP001. Next, I have to be honest with you… I started brewing in 1999 and one reason was because I wanted to make various fruit-infused beers. Raspberry, Strawberry, Blackberry, Blueberry, you name it. You know what? Making beer with real fruit or puree (where natural sugars are present) is tough. My approach is to use gourmet fruit extracts that you find on the web, not at your LHBS. These things are meant for cooking and are all-natural, sugar-free and taste and smell great. Add about an ounce to secondary and see how it is. If it’s too little, add more. I just made a Raspberry Ale last weekend with pale malt, wheat, vienna, special b and some crystal malt. 1 hop addition of Liberty and also Saphir to about 5 AAUs for 60 mins. I used the special b and crystal to give it a red color (to simulate the raspberry) and when it goes to a keg, I will drop one ounce of McCormick Natural raspberry extract to the keg. This stuff smells and tastes fresh and delicious and nothing like the cough-syrupy stuff from the LHBS. Good luck on the next batch.