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Foam Stopper 35-45mm


SKU# 7090

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Breathable foam stoppers will withstand boiling or autoclaving temperatures, making them ideal for use in preparing a yeast starter. Fits 500 or 1000 ml flasks.


Availability: In stock

Foam Stopper 35-45mm

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  • Foam Stopper 35-45mm
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'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 small foam stoppers are 35-45mm wide and fit our 500 or 1000 ml borosilicate glass flasks, or a glass carboy.

Additional Information
Support Documents:No
5.0 / 5.0
8 Reviews
5 Stars
4 Stars
3 Stars
2 Stars
1 Stars
Pretty nifty!
Actual diameter is 45mm or 1 3/4". My Kimax 5000ml flask has a 42mm opening and this fits perfect. It can of course be squished as small as you want it.
August 24, 2017
8 months ago
Silencing the wife and promoting algae growth
I freakin love em. I stuff em in my ears so I don't have to hear the wife blabbering. And they provide the appropriate air exchange for my algae cultures.
August 8, 2017
9 months ago
Works perfectly
Works perfectly. Allows air in to oxygenate started and keeps dust out.
April 22, 2017
1 year ago
As cheap as these things are (NB please don't up the price) I buy a few with each order I make. They're easily sanitized, and actually could take a lot of use before being pitched. Follow their sizing instructions to make sure you're buying the right size for your e flasks.
September 21, 2016
Finally someone made what I thought of doing
This worked great, the starter took off in several hours, and now no worries of contamination.
August 14, 2016
foam stopper
Perfect for flasks.cleans up well!
May 4, 2016
great for yeast starters
I use this on my 1/2 gal jugs to make yeast starters
December 21, 2013
Excellent product
Have used these many times for my yeast starters and have never had any problems with infection. Just clean it and pop it in before boiling your starter solution. The steam from the boil sanitizes the foam. They're much easier to use compared to a stopper and bubbler.
August 12, 2009
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