It's been a long, cold, rainy spring in China - the perfect weather for hot milk tea and for chai. I love chai, but I hate paying for it, and I'm just way too lazy to make it in small quantities. My problem was solved by the wonderful concept of making a single, massive batch of chai concentrate.
You boil up dry spices (cinnamon, star anise, cloves, cardamom, black pepper), separately boil up a bunch of sliced ginger, add black tea, and steep briefly. Add some sugar, and that's it.
My batch yielded five bottles. The concentrate will last for at least a few weeks in the fridge (assuming you don't drink it all before then!).