I would pull a 12oz sample out of your fermentor, brew a STRONG cup of tea with a KNOWN amount of tea leaves and then add it 1/4tsp at a time to your sample. If you have some measuring spoons, you'll probably have a 1/4tsp. Make sure the tea is strong (more leaves per cup of water than you would usually make), but steeped at the correct temperature (and not very long) to avoid getting any astringency at all which is super easy to do with tea.
I can't be arsed to keep up this list of what's in the fermenters, but hey, check out the cool brewery I'm opening up!
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