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Foam Stopper 46-50mm

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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 & 5000 ml flasks.
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Additional Information

5.0 / 5.0
17 Reviews
5 Stars
4 Stars
3 Stars
2 Stars
1 Star
Bug barrier
It lets the air flow in and keeps out dust and bugs so my yeast starters can glow without contamination. This size fits the 2000ML flasks better than the other sized foam stoppers.
October 8, 2013
needed to make a starter in a flask
I was a bit weary to use one of these when I first started making starters. I thought that the yeast needed to be airtight in the flask just like when fermenting. This allows airflow in and out of the flask but also filters that air. I haven't had a contaminated batch using this yet. And every starter I have made has only made the beer better than the first time I brewed it with direct pitch. So yes, this item is worth it.
August 5, 2013
Instant air lock for flasks
Easy to use ,just dip in Star San and insert it in the top of the flask._x000D_Easy to clean, just wash with dish liquid and warm water._x000D_Better than an air lock and stopper because the yeast aren't under pressure and Oxygen can reach the yeast.
December 4, 2013
Better than a stopper for starters
For starters you want the free exchange of gasses and no pressure on the yeast._x000D_The stopper is easy to sanitize by soaking in Star San, and then lets the CO2 out.
January 23, 2014
Lets Oxygen in and CO2 out
I use this for my starters so the yeast and starter solution can get rid of CO2 and get in fresh O2 so the yeast grow faster,
February 8, 2014
Keep it clean
Really good for yeast growth. This is the second I've bought. The first I kept in a bin with bottle caps, twist ties, etc. Realised my mistake when a starter went sour. If the porous material get's dirty even sanitizing won't do much good. Keep it immaculate or replace it regularly.
February 20, 2014
Use for Yeast Starters
These stoppers are great for using with Yeast Starters or when washing yeast using a 2000 ML flask. Drilled stoppers and airlocks are not necessary for starters and these foam stoppers are easier to sanitize and fit than aluminum foil.
November 9, 2012
great addition for yeast starters
I just went ahead and bought a handful of these to use for future yeast starters. Not sure if they "go bad" or not but at some point I just feel more comfortable replacing them once they start to look a little shabby. Seems safer than aluminum foil and allows for adequate transfer of gases.
November 24, 2012
Better than an airlock
Works better than an airlock on starters-can be inserted as soon as you finish boiling. Also fits in the mouth of my 5 gallon carboys, to keep them sanitary in storage.
December 28, 2012
for yeast starter
I use these on my yeast starters. For yeast starters you want a free exchange of carbon dioxide and oxygen. This allows more O2 into the flask and lets CO2 escape. The foam will keep dust from settling into your starter.
January 25, 2013
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