We have a goumi bush in our yard, under the
Paulownia tree. Every year we are innundated by gadzillions of the little red berries, which are sour and astringent before fully ripe, and just sour as lemons after they are ripe. What a bargain. We have tried making jam out of them for a couple of years, but this year we decided to try something new.
Start with one kilogram of
goumi berries. Make sure you pull off each and every one of the stems from the several hundred berries. That should keep you busy for a while.
Ok, you have the one kilo of berries, now you need to put them in the jar.

Cover them with one kilogram of rock sugar. Well, any kind of sugar will work.
Now pour 1.8L of "White Liquor" over the berries and sugar. White Liquor is basically a 35% grain alcohol. Japanese
Shochu, Korean Soju are good, Vodka... Well, I guess it might work.
Everclear- That would work pretty well.
Now this is the hard part..... Wait three weeks before drinking.