Might be caused by incomplete fermentation. Do you check your wines with a
hydrometer? Did you stabilize your wine before degassing and bottling?

--
Sales Associate
Brewery Lane,
Mt.Pearl Plaza
7 a Commonwealth Ave
Mt.Pearl, NL A1N 1W3
(P) 709-745-1140 (F) 709-745-1618


"Murray Clark" > wrote in message
...
> Today my father happened to be in the basement and heard a funny noise in
> our wine-room. A bottle of blueberry wine from last summer's batch
> actually blew its cork. We tasted some of the 2/3 that remained and was it
> ever good. We knew these berries were sweeter than usual when they were
> picked, but did not expect the wine to taste even sweeter. Does anyone
> have a similar experience, or perhaps an explaination for this?