Accuvin test are not very accurate to begin with and I would certainly not trust a 2.5yr old test kit. If this has been stored in glass and properly topped up the entire time and you have added a top up dose of sulfite every 3-4 months then it should still be at a decent level. The only real accurate way to test for sulfites is with the Vinemetrica analyzer (one of our sponsors) or via an A/O analysis. Accuvin's test kits are like throwing darts at a dart board IMHO.
The opinions expressed in this forum are strictly my own,
and should not be construed as the opinion or policy
of WineMakingTalk.com or its owners
"In vino veritas" - Visit the Château!
Location: Lost Almost, NM