I picked up a bottle of Tolly Cobbold Royal Wedding Ale from 1981 at an auction recently. There were not many other bidders. It was still drinkable and tasted like wedding cake. There was some sediment at the bottom of the bottle. As the beer was still good I was curious about the yeast. The beer tasted dry - rich but not sweet. I guessed the yeast had over the years continued to convert sugar until any sweetness had all but gone. As an experiment I put a mix of malt extract and water into the bottle to see if any yeast was still alive. I didn't think it would be but I didn't have anything to loose except a few spoonfuls of malt. To my astonishment after 2 or 3 days in the airing cupboard it has started bubbling! Has any one else reactivated really old yeast for brewing? Should I make some new beer with it?