Varieties include Bergamot, Bigarde, Box-leaved, Curled-leaf, Chinotto, Seville, and Smooth Seville.
Equal portions of freshly-squeezed orange juice and freshly-squeezed lime juice.
Bitter oranges originated as a hybrid between mandarin oranges and pummelos in China. Documented in China by 300 BC. Had reached Rome by 100 BC, and Japan by 100 AD.