I primarily use ash to make jelly. In my opinion, straight ash jelly is too bitter. I mix it with apple. Each tree is different in its level of bitterness, so you’ll have to experiment, but I find that a 25% ash/75% apple is a decent ratio for maximizing flavor and minimizing bitterness (see jar on the left). For the more hardcore ash lovers, you may want to go as high as a 75% ash/25% apple ratio (see jar on the right).