I've got an interest in the 30-second blanch issue, which has been questioned here as an old conundrum recently. But now, as I read more about water quality, customs, and practices, I'm picking up additional info that seem to support 30-seconding.
- Tea leaves do have some taste resulting from organic defense against aphids, etc.. It's a jungle out there and the species has its survival mechanisms, evidently including exuding it's own repellant.
- Farmers do spray their crops with chems, and even "organic" tea leaves might get dosed a bit. And does the irrigation system, if any, use chlorine, fluoride, etc.?
- During processing, who knows what chems are used to ferment, decaffe, add taste, etc.?
- In various stages of collecting, processing, and storing tea leaves, it's likely that insect and animal droppings are deposited.
- Personally, the green teas I savor do have a somewhat dank and weedy taste on first infusion.
So, adding it up, it looks like a 30-second blanch of leaves is the right thing for me to do. So far, I haven't any preference about temps, except that less than 140 F. seems desirable. Don't know what higher temps at sea level do for blanches and steeps, generally or on individual teas. bookburn