Yeast beer (they are called "Zacharomycus carlsbergensis") is a yeast that is produced in the beer production as an accompaniment. And are also called "lower beer yeasts" because they sink to the bottom of the beer as well. There are other yeasts that come up over the beer night in the foam layer, some of which are used to make new beer, but most of them are considered waste and are thrown into the pouring water. Because of the hops that give them the bitter taste, by soaking in a 1% to 2% solution of soda or sodium carbonate or ammonium carbonate and washing them in water that neutralizes the lime in a weak acidic solution and drying them. Because the beer preserves are high in high nutritional proteins , They are a source of vitamins in me, and some of these yeasts are ultraviolet to enrich with vitamin D.