Breathable foam stoppers will withstand boiling or autoclaving temperatures, making them ideal for use in preparing a yeast starter. The honeycomb structure of the foam stoppers will act as a filter for any airborne bacteria or wild yeast that might enter the flask. That's important because a lot of air is sucked into the flask while it is cooling. You can also leave the stoppers on the flask instead of a fermentation lock. Some people use foam stoppers to replace fermentation locks in their carboys, too.
The large foam stoppers are 46-60 mm wide and fit our 2000 and 5000 ml borosilicate glass flasks.
Actual O.D. is 63mm or 2-1/2". Gotta reach 50 characters for review...that enough?
S
S.G.
Great for yeast starters. No longer have to worry about bugs getting into my flask, or having to use the airlock with cotton balls in the top.
M
M.B.
Pops out of 3L flask
Maybe it's due to it being a new stopper and the foam is still rigid and has only somewhat softened up yet after a few uses. It worked it's way out of my 3L flask overnight the first time I used it which let a fruit fly in. The last couple of times I've used it I've covered the foam stopper with tinfoil and wrapped an elastic around it almost defeating the purpose.
N
N.N.
It's a foam stopper.
It's Foam. It stops.
T
T.L.
Missing a foam stopper
Well, I checked the box. Found missing one of the stopper. Everything else are very well packed.
I am very sorry about the missing stopper from your order. I am having a replacement shipped out to you right away. I hope this helps!
