Put 1 gallon of distilled water in the pot. Add 1 cup of loose tea mixture. Mix the tea in the water. Let this mixture sit in the water overnight in the refrigerator. You can even let it sit a few days. The longer you let it sit, within reason, the stronger the tea will be.
Heat the tea, but NOT to a boil. Let the tea simmer. Pour the strained tea back into the pot. Simmer this solution down to one-fourth its original volume.