Foam Stopper for Erlenmeyer Flask

This Foam Stopper is for use with an Erlenmeyer Flask or yeast starter. This is the same Foam Stopper included in our Beer Brewing Yeast Starter Kit. A breathable foam stopper is ideal for use in making a yeast starter in an Erlenmeyer Flask. It can withstand boiling temperatures and helps keep dust out of the flask. This foam stopper is 1 ¾” diameter, and fits our 1000 mlL and 2000 mL borosilicate glass flasks.