Product Description
This 1 ¾” foam stopper for 1000 & 2000 ml flask has been specifically developed to meet the exacting requirements of quality filtration foam. Us the foam stopper in place of an air lock or foil when making a yeast starter. The breathable foam will let air in but filter out wild yeast and bacteria. Once fermentation begins the stopper will allow CO2 to escape. Also fits 3,5,and 6.5 gallon carboys.
