Soaking Gum Crystals: To make gum ammoniac size, I crushed up about a tablespoon of raw crystals and removed the noticeable impurities—sticks, seeds, sand—with a pair of tweezers. I put the crushed crystals in a glass jar and added just enough distilled water to cover them, capped the jar with Saran wrap and a rubber band, and let it soak overnight, for about 12 hours, to soften up.