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Foam Stopper 46-50mm


SKU# 7091

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Breathable foam stoppers will withstand boiling or autoclaving temperatures, making them ideal for use in preparing a yeast starter. Fits 2000 ml flasks.


Availability: In stock

Foam Stopper 46-50mm

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  • Foam Stopper 46-50mm
  • Foam Stopper 46-50mm
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 large foam stoppers are 46-50 mm wide and fit our 2000 ml borosilicate glass flasks.

Additional Information
Support Documents:No
4.9 / 5.0
10 Reviews
5 Stars
4 Stars
3 Stars
2 Stars
1 Stars
Actual diameter just under 50mm or about 1-15/16".
October 25, 2017
6 months ago
Works perfectly
Works perfectly. Allows the starter to breath and keeps the nasty stuff out
April 22, 2017
1 year ago
Pretty solid
Works very well in my beaker when making starters. But I don't really know how to clean it after each use. I just dunk it in sanitizer and hope it's clean. Came with no cleaning instructions which is why I rated 4/5*
October 4, 2016
Perfect for 2000 ml flask
Perfect for 2000 ml flask
July 31, 2016
Perfect for yeast starters
Wet with sanitizer and insert into flask. Yeast stays oxygenated and infection free. Sure beats loose foil with a rubber band.
April 24, 2016
Foam stopper
Works good
April 24, 2016
Good Fit
Easy to sanitize, fits beaker perfectly.
December 28, 2015
Works great!
Works great!
October 9, 2015
Foam Stoppers
If you are making yeast starters, these foam stoppers are a must for your flask. I tried making some, but could not come close to these Northern Brewer Foam Stoppers.
January 15, 2014
Works great with a yeast starter
I use one of these with a 2000ml flask for a yeast starter and it works great.It lets the gas escape, and I haven't had an infection yet (knock on wood).I simply soak mine with a little star-san solution and squeeze it dry.Very easy to insert and take out.
February 26, 2010
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What is the lifespan of a foam stopper?
A shopper on Mar 15, 2017
BEST ANSWER: If you keep it clean and sterile, and depending how often you use it, a year or two. I did notice a little bit of discoloration but that's about it.

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