Raspberry Cream Ale

Hey guys,
I made a raspberry cream ale on 10-03 of last month. I put it in the secondary on 10-23, and primed two 16oz bottles of it on the same day. Three days ago I put one in the fridge and had it last night. It had a very bad aftertaste.
Here is my recipe:
11lbs American Pale Malt (brewers 2 row)
0.5lbs American Crystal 60L
1lbs American Dextrin Malt
1tsp geleton
3/4 cup priming sugar
5oz raspberry concentrate

Hops:
Hallertau (German) Leaf 1/2 oz 30min 1/2 oz 2mins
Willamette Leaf 1/2 oz 30min
Cascade Leaf 1/2 oz 30min

Yeast: WLP080 Cream Ale Yeast Blend


SG: 1.056


Any idea why I have a bad aftertaste? I was really excited about this beer and the aftertaste is a real disappointment. Do I have to let it sit longer or something? I plan on making another raspberry cream ale, probably with a different recipe with flaked corn or rice. Any help with this issue or another recipe would be greatly appreciated.

Sorry for the double post.

You might want to elaborate on the aftertaste. I've made two raspberry beers, a hefeweizen and a light ale. I only used fruit (puree) in the hef and it had a nice fruit flavor. In the light ale I used an extract and it tasted kind of like cough syrup. Not super terrible, but not nice either. Just my experience.

Monk

I'm not sure how to explain it. Maybe a little like cough syrup and a little sulfery. If that makes any sense.

It sounds like it might just be green. I made a couple beers with fruit/pumpkin in them and they were very bitter during the entire brewing and bottling. I had to let them sit and condition for 3 weeks before they were good.

Some concentrates can be a bit odd, that might be where the cough syrup note is coming from. Sulfur is probably from the yeast and should age out.