First brewed a 2005 Shui Xian Oolong from Hou de in a tiny gaiwan to see if the not-quite-right flavor I was getting brewing it in a Yixing was the pot or the tea.
The tea. A bit off on this aging tea. Dusty, musty. Not too surprising. I have had it a while and I have enough of it to make it worthwhile to try re-roasting it. I'll post about that when I get around to doing the re-roast.
It's not that unusual for a tea to go stale if it is old. My understanding is that you probably need to re-roast many teas if you keep them more than a year. Teas that are purposefully aged are re-roasted annually.
Interestingly this came up with an aged tgy that I got from Greg at Norbutea.com a few months ago. I contacted Greg and told him the vacuum sealed package I got was off when I opened it and asked if this was a general problem or if I just happened to get the bottom of the bulk dregs. He was really surprised because he had opened a couple of packages when he received the shipment and it was fine. But he opened a couple more and they were off, too. So he emptied all the vacuum packs, re-roasted all of it, gave me a replacement and offered to re-roast my first batch.
Greg has a cool little tea roaster made of bamboo. You can get these from several tea merchants - Hou de and Yunnan Sourcing both carry them I believe. Less than $100. It looks similar to a stack of those bamboo steamers, and has a low-power heating element in the bottom. You can re-roast in the oven also if you are careful.
So I may try the oven. Trickier than the bamboo roaster and makes me a little nervous.
Has anyone else re-roasted in the oven? What temp and time did you use? Did you put it on a half-sheet covered with aluminum foil or something else? Leave it on the sheet to cool or dump it?