500 ml borosilicate glass flask is great for storing harvested yeast or stepping up slants or old yeast. Takes a #7 stopper or 35-45 mm foam stopper - for optimum fit, especially when propagating yeast, we highly recommend using a foam stopper.

Borosilicate glass tolerates rapid changes in temperature, making these flasks ideal for preparing yeast starters. Just boil your wort in the flask to sanitize the foam stopper. Place the flask directly on a gas stove, then move it to an ice bath to chill! Not recommended for use with electric stove elements!