The Erlenmeyer Flask - 2000 mL (Y430) is ideal for yeast culturing. Constructed from borosilicate glass, this flask can be transferred directly from high to low temperatures without breakage making it perfect for yeast starters. The flask works best when the heat source is completely even. Because of this, placing the flask directly on an electric range is not recommended. If it is unavoidable, it is recommended that you use the double boiler method in which you boil water in a pot and place the flask into the boiling water. A 3-gallon or larger pot is suitable for this method.