>>90223116green tea has more caffeine, but it needs to be steeped at a lower temperature and for a shorter time. the best way is to just use more; longer steeping just cooks it and extracts bad flavors. yerba mate (roasted holly leaves, with lots of caffeine) is usually consumed in a large container and passed around like a bong, so you might try that instead. if you're using whole leaf tea, black tea can be reused two or three times instead of just steeping the shit out of it.
for what you're trying to do... maybe just heat some milk on the stove and steep some teabags and whole spices in it. or just get some chai teabags. if it's almond milk, it won't burn or curdle and you can just boil it.
