According to the ladies over at hennaforhair.com many teas have a certain level of acidity (green tea, chamomile (sp?), hibiscus, etc.) and therefore, the tea mixed with filtered water eliminates the need for a liquid with a higher acidity level. The dye release was the same, but my hair came out softer and smoother.

I brought a cup of water to a boil, let it cool for 1 minute then steeped 2 organic green tea bags (from an Asian Market...can't read the name brand, because it's not English, lol) for 3 minutes. I let the tea cool and then mixed it with 100g of henna.

hth
The Blog: www.curlynikki.com