Which of these is used to thicken kissel - a viscous fruit dish?

Kissel or kisel is a viscous fruit dish, popular as a dessert and as a drink in Northern, Central and Eastern Europe. It consists of the sweetened juice of berries, like mors, but it is thickened with cornstarch, potato starch or arrowroot; sometimes red wine or fresh or dried fruits are added.

Kissel can be served either hot or cold, also together with sweetened quark or semolina pudding. Kissel can also be served on pancakes or with ice cream. If the kissel is made using less thickening starch, it can be drunk — this is common in Poland, Russia and Ukraine.

Nowadays most Polish households prepare kissel from instant mixes instead of the traditional way.

In Russian fairy tales, the land of marvels (similar to Cockaigne) is described as the land of "milk rivers and kissel banks". This expression became an idiom in Russian for prosperous life or "paradise on earth".

Another phrase common in Russia and Poland, "the seventh water after kissel" is used to describe a distant relative.