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Reviews with images
Good idea but may need additional seals
In homebrewing beer, it’s quite usual to prepare a yeast starter prior to addition to the wort. Yeast starters are prepared in a 1 to 2-liter vessel by adding a packet or vial of purchased yeast (or bottle dregs) to enough wort to half fill the vessel. The starter is left for one or two days, normally with stirring, for the quantity of yeast to build up enough to give a good final fermentation. It’s quite common to leave the starter exposed to ambient air to help promote yeast growth. While it is important to let the air reach the starter, letting bacteria and other microbes in is not good as there will be a real risk of infection that could ruin an otherwise award-winning beer. To keep bacteria out, a cotton wool plug, a small sponge or a piece of aluminum foil can be applied to the mouth of the vessel. While these all help, they are not perfect and it’s still possible for bacteria to find a way in – particularly if the yeast in the starter has finished its job.I saw these PTFE patches on Amazon designed to protect the sanitation of mushrooms in Mason jars. I didn’t know people grew mushrooms in Mason jars before. Anyway, I quite often make beer starters in Mason jars, so I thought these patches might be ideal for this purpose.The product includes 18 permeable PTFE (Teflon) patches with 0.3µm pores that won't allow the passage of bacteria. These patches are mounted on sheets of transparent plastic with a ring of strong adhesive around the edge of each. To use, they are simply peeled off and stuck onto the outside of the threaded metal ring that normally seals the lid against the rim of the Mason jar. This is where I had an issue – it is normally the disk-shaped lid that seals in the contents of the Mason jar. When this lid is removed (as when using these patches), there is no longer a good seal between the metal ring and the jar, and so although the membrane will filter the air diffusing through it, air containing microbes could go around the ring and into the jar. Another potential problem is that the inner surface of the ring can rust which is not a problem if a inner disk lid is used but may release bits of rust or bacteria otherwise. A quick search of Amazon revealed that silicone seals can be purchased for Mason jars that would then offer full protection.I like that these PTFE membrane patches can be boiled/autoclaved and, presumably, treated with sanitizing agents like StarSan allowing re-use.It’s difficult to test their efficacy without access to a microbiology lab but they seemed to do a good job.I don’t know if anyone else has tried using these patches for preparing beer starters – but they appeared to work for me.
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Top reviews from other countries
Spina
kleben gut, filtern gut
Reviewed in Germany on April 18, 2024Size: 20mm(64pcs)Verified Purchase
Leonardo Verzegnassi Trevisan
Ideal for home grown mushroom
Reviewed in Italy on February 24, 2024Size: 20mm(64pcs)Verified Purchase
Eugenio
ottimi risultati anche se con utilizzo non convenzionate
Reviewed in Italy on February 6, 2024Size: 65mm(18pcs)Verified Purchase
Amazon Customer
Sticks to lid after pressure cook
Reviewed in Australia on September 30, 2023Size: 20mm(64pcs)Verified Purchase
