#9 - #10 Foam Stopper

  • Item #Q34
  • Price: $1.39
  • Part #
- +

In stock, will ship on Tuesday, July 5

Versatile stopper that fits our 2000 ML Erlenmeyer Flask. Use as an airlock for yeast culturing, and even more useful as a sterile shield when preparing media. The proprietary foam is heat-resistant, and will withstand autoclaving or pressure cooking, making it an ideal flask plug when preparing sterile wort and agar. The honeycomb structure of the foam lets the plugged flask breathe, yet bacteria and wild yeast are filtered out and cannot reach the media. This means you can put your media in an Erlenmeyer flask, plug with a Foam Stopper, and pressure cook to sterilize, fully confident that bacteria and wild yeast will not enter the flask, even during the cooling and later storage period outside the pressure cooker.

Also great to use as an airlock for a 5 or 6½ gallon carboy. Just replace your stopper and airlock with the foam stopper. 2" diameter, 2 1/4" tall.

Average rating 10 out of 10 ( based on 5 reviews )

Excellent Product

Review by Jason Gray on 1/12/2016

I have used this product for several years now. This stopper does a great job for all of my yeast starters on a stir-plate. I sterilize with Iodophor before using it with my 1000 or 2000 ml flasks. I also use the stopper to top my carboys when they are being sterilized, and instead of an airlock after I have dry-hopped. All positive with no negatives. 5 stars.


Review by Joseph on 1/28/2014

I use these instead of foil. They are easy to sanatize. I just feel a little afer using these.

Excellent product

Review by Jerry on 2/21/2013

I have used this for over a year. Does a great job for all of my yeast starters on the Stir starter stir-plate sold here at Williams. I sterilize with Star San. This is good for getting maximum yeast growth for a very inexpensive price instead of tin foil on the flask. I use a 2000 Ml flask. All positive with no negatives. 5 stars.

Easy to use

Review by Robert on 3/24/2012

I put these on the flask during the boil so they are sanitized by the escape steam during the 15 minute boil time. Easy to clean, last through several batches. Never had contamination issues.

Easier than multipiece airlocks.

Review by DANIEL A. on 5/13/2011

I've done well with these stoppers in a flask for yeast starters. I boil them before each use for sterility and they hold up nicely.

Ask a Question