what can you substitute for pectin?

Answer 1

You can substitute carageenan or agar agar. They set more solidly than pectin so you might have to adjust quantitles a little.

Answer 2

Apples, quince, plums, gooseberries and oranges contain much pectin, while soft fruits like cherries, grapes and strawberries contain little pectin.

If you are making jelly from a low pectin fruit, you can increase the natural pectin content by combining the fruit with another high pectin fruit, like apples or quince.

My grandmother never added pectin to her jellies. She thought it affected the taste. But she did use more sugar than those who did use pectin. And the additional sugar helped the jelly to set properly.