A mate of mine gave me a bag of hops (about 100g of unknown variety) that he got from a farm where they grow them. I never got around to using them and have stored them cool(ish) and dry but not in fridge or freezer for about 6 months. Would they still be any good? How long should they last for? Could old hops ruin a beer? What do you reckon, should I toss them or use them? They are in an open bag so would there be a contamination risk if using them for dry-hopping?