Comment by masklinn
3 years ago
The more sensitive "proper" teas are well into the danger zones e.g. gyokuros tend to be brewed between 50C and 60C, and with brewing times under 3mn.
Never really heard of hard thermal limits for herbals though, in my experience they're more resilient and less caring, and you can long-boil most of them like you'd do a middling black tea.
By that standard, you should be really careful with matcha — you mix it will non-bacteria-killing water and then drink the whole thing!
I don’t know whether most pathogenic bacteria can survive prolonged dry storage conditions, though. And, if you’re worried, you could likely pasteurize your fancy tea by heating it, dry, to 60C or so for a while.
I’m not even remotely worried about tea-borne salmonella, just pointing out that per your link for higher-grade green teas the brewing temperature x brewing time is well below what’d be needed to destroy it.