Foam Stopper (Autoclavable)

Foam Stopper (Autoclavable)

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Use this foam stopper with your Erelenmeyer flask when making a yeast starter. Aeration is an important aspect of making a strong, healthy starter. This is why we recommend using a stir plate, which provides continuous aeration. This foam stopper will allow air to flow freely into your flask while keeping pesky bugs and other contaminants out. A quick spray down with sanitizer is all you need. Suitable for flasks or other vessels with an inner diameter opening of 35-45mm (1-3/8" - 1-3/4").

  • Reusable
  • Resists alcohols, bases, esters, and dilute acids
  • Autoclavable up to 249°F (121°C).
Community Q&A

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Why did you choose this?
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looks to fit flask, was recommended
Christopher T on Aug 31, 2022
To use while making yeast starter from making beer.
Bobby C on Aug 22, 2022
looks to fit flask, was recommended
Christopher T on Aug 31, 2022
correct size and specs
To use while making yeast starter from making beer.
Bobby C on Aug 22, 2022
To have an extra for making yeast starters
Glen D on Jul 23, 2022
I hope they are better than foil.
John Thomason on Jun 8, 2022
I like the stoppers better than foil.
Will C on May 27, 2022
Just ordered yeast starter kit and getting incase I lose original.
Jeffery Mark H on Apr 30, 2022
I prefer these over aluminum foil - I replace them after using for a while
Gary C on Apr 13, 2022
goes with flask
David W on Apr 1, 2022
fermentation air lock
George T on Mar 15, 2022
Need it
Eric J on Mar 14, 2022
Top off E flask for yeast starters
Eric T on Jan 28, 2022
Works great making starters
Gary C on Jan 22, 2022
Yeast starter
Thomas Carter on Jan 22, 2022
better than tinfoil to seal flas
Brian M on Nov 27, 2021
yeast starter
Andrew T K on Nov 24, 2021
To cap off my flask during the starter process
Cody King on Nov 23, 2021
Yeast starters
Elias C on Nov 22, 2021
yeast culturing
Trevor Mack on Nov 17, 2021
extra stoppers
Doug Haviland on Oct 13, 2021
Better option than foil because it breathes
Arlene P on Sep 18, 2021
Orin D on Aug 6, 2021
For a yeast starter flask
Levi Stephen K on Mar 27, 2021
i need one
jason p on Mar 11, 2021
For my yeast starter flask.
Kevin Smith on Jan 29, 2021
Going to use a yeast starter for my next batch
Joshua P on Jan 12, 2021
Need it for yeast starting
Harold N on Nov 19, 2020
breathing release yeast
Gary Sanger on Sep 22, 2020
Stopper for my yeast starter flask
Orion K on Aug 27, 2020
yeast starter
David San C on Jul 28, 2020
I make a lot of starters, but but typically use tin foil
Horst Sprader on Jul 4, 2020
Pete T on Jun 9, 2020
Need for flask
Winfrey J on May 28, 2020
Better than tinfoil
Drewbrewski on May 28, 2020
Making yeast starter
Myles F on May 20, 2020
need it to make beer
Lantz P on May 13, 2020
old one is getting scuzzy looking
Eric M on May 9, 2020
For Erlenmeyer flask; while using stir plate
Kerry Shaver on Apr 25, 2020
For Erlenmeyer flask.
Kimberly on Apr 21, 2020
Hopefully will work well with flasks
ROY W. on Mar 17, 2020
My other one was "eaten" by prolonged exposure to sanitizer.
David O on Mar 12, 2020
good price
Marco a L on Feb 25, 2020
Better than nothing
Steven L on Feb 7, 2020
Very useful product for yeast starter flasks.
Douglas B. on Feb 1, 2020
Recommended with Flask
Dale Z on Jan 16, 2020
for making yeast starter
Hyungsoo K on Jan 10, 2020
To fit flask, for making starters
ROY W. on Jan 8, 2020
It works with the yeast starter kit
Aaron C on Dec 13, 2019
I like this is reusable and can be autoclaved to sanitation.
Nelson L on Dec 2, 2019
Mike on Nov 18, 2019
correct size and specs
To have an extra for making yeast starters
Glen D on Jul 23, 2022

4.9 / 5.0
15 Reviews
5 Stars
4 Stars
3 Stars
2 Stars
1 Star
Rated 5 out of 5
Better Than Foil
This is has made foil obsolete.
June 21, 2022
3 months ago
Rated 5 out of 5
As advertised. Very happy
May 11, 2022
4 months ago
Rated 5 out of 5
These stoppers are great for yeast starters in an Erlenmeyer flask. Keeps bacteria out while allowing airflow
March 9, 2022
6 months ago
Rated 5 out of 5
Just what I needed.
It fits nicely in my 5 liter flask.
February 2, 2022
8 months ago
Rated 5 out of 5
Bought a 10-pack because I'll probably lose or misplace them. Fits my starter flask perfectly.
December 27, 2021
9 months ago
Rated 5 out of 5
Does the job as expected
These stoppers do the job as advertised
January 7, 2021
1 year ago
Rated 5 out of 5
Perfect stopper for starter flask
Only used once, but perfect fit on 2000 ml starter flask.
January 2, 2021
1 year ago
Rated 5 out of 5
Yeast starter last minute
I tried this with soy venting sanitized jug and had too watch very careful LOL pay’s to have right stuff. (was out aluminum foil)
October 5, 2020
1 year ago
Rated 5 out of 5
Works as advertised.
July 8, 2020
over 2 years ago
Rated 5 out of 5
Great little stopper
My starter flask just loves her new foam stopper, so spongy, easy to sanitize, and sooo comfortable. Can’t wait for those little yeasty’s to try to get out as there’re in for a big surprise.
Defying gravity
Defying gravity
June 16, 2020
over 2 years ago