Originally Posted by Orangevango
I get a TON of grape soda smell off of fullers london porter.
I don't think you did anything wrong....I don't think it's fermentation temps nor do I think it's necessarily
cloramines either...though chloramines could come into play, possibly.
Certain dark roasted malts can impart what is often called "Dark Fruit" flavors in some beers. Flavors like Fig, and Raisin, especially in the presence of non fermentable sugars like lactose...Add a malt that at a certain level in a graibill is "raisiny" to any residual sweetness and you get something like grape soda. If you do have chloramines combined with dark malts maybe the taste would be a bit medicinal...
My chocolate mole porter tasted like grape soda while it was still young, and green, but that faded with time, more than likely yours will too.