Foam Stopper 46-50mm

$2.99
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Product details

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 is a filter for any airborne bacteria or wild yeast that might enter the flask. That 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 46-50 mm wide and fit our 2000 ml borosilicate glass flasks.

Additional information

SKU

42950

Customer Reviews

Based on 24 reviews
96%
(23)
4%
(1)
0%
(0)
0%
(0)
0%
(0)
E
Eric W.
Does the job

I always use a foam stopper like this one in my 2L flask when doing starters. Makes me feel a little more secure than just using foil, which I originally did. The foam stopper keeps anyone from getting in, but is not so tight that a particularly active starter can't push it out with no problem. When that has happened, the stopper just sort of sits on the top, still pretty much doing its job. Thankfully, no absolute gushers yet...

L
Logan

Foam Stopper 46-50mm

R
Reese M.
Larger Foam Stopper

This came in handy when I had to use a 2000 ml beaker to start my yeast for an Imperial Red Ale. Easy to use and easy to clean.

M
Michael B.
Flask stopper

I use it for my yeast starter flask. When swirling the starter try not to let it touch the stopper because that stain doesn't come out.

M
Mike
Works perfectly

Fits my 2L flask i use for yeast starters perfectly. Makes a nice, tight fit that keeps dust out and lets the starter breath. as with any foam, these have about a 9 month lifetime for me, but i can soak up sanitizer, squeeze it out and let it work.

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Foam Stopper 46-50mm

Foam Stopper 46-50mm

Customer Reviews

Based on 24 reviews
96%
(23)
4%
(1)
0%
(0)
0%
(0)
0%
(0)
E
Eric W.
Does the job

I always use a foam stopper like this one in my 2L flask when doing starters. Makes me feel a little more secure than just using foil, which I originally did. The foam stopper keeps anyone from getting in, but is not so tight that a particularly active starter can't push it out with no problem. When that has happened, the stopper just sort of sits on the top, still pretty much doing its job. Thankfully, no absolute gushers yet...

L
Logan

Foam Stopper 46-50mm

R
Reese M.
Larger Foam Stopper

This came in handy when I had to use a 2000 ml beaker to start my yeast for an Imperial Red Ale. Easy to use and easy to clean.

M
Michael B.
Flask stopper

I use it for my yeast starter flask. When swirling the starter try not to let it touch the stopper because that stain doesn't come out.

M
Mike
Works perfectly

Fits my 2L flask i use for yeast starters perfectly. Makes a nice, tight fit that keeps dust out and lets the starter breath. as with any foam, these have about a 9 month lifetime for me, but i can soak up sanitizer, squeeze it out and let it work.