I cooked a litre of soybeans for two hours and cooled them for 15*. I should put them in the refrigerator, but in what solution? My intuition says that an acidic liquid would work. Should I use one teaspoon of citric acid to make them acidic?
*Note (Jefromi): the title said "15h cooled and then 2h cooked" soybeans. I tried not to change the meaning, but I suspect that the OP may have actually meant that the soybeans were soaked for 15 hours, then cooked.