You are definitely tasting it very young. Are you sure the fermentation had finished after just one week (by using a hydrometer)? If not, there could be residual sugars making it taste sweet. I would normally expect to ferment for nearer 2 weeks, followed by the bottles being in the warm for 2 weeks and then 2 weeks in the cold after that. Some beers can take 2 months of conditioning in the cold before they are really worth drinking.