Another week, another new home brewing gadget

[Lyrebird_Cycles]

Re Tritan, Eastman's tech sheet gives an oxygen transfer rate in 24 hours of 32 cc oxygen per cubic metre of a barrier 0.1 mm thick.. That's at a one-atmosphere partial pressure differential, which is about what you'd expect between the outside air and an oxygen-free, unpressurised fermenter. If the walls of the "Catalyst" are 5 mm, the rate would be 1.6 cc/sq meter in 24 hrs. That's not negligible.

It looks like Tritan is meant to cash in on worries about bisphenol leaching from container walls. That's a debate in its own right.

1 atmosphere partial pressure differential is approximately 100kPa, so more analogous to a keg than an unpressurised fermenter. Similar to HDPE, I cannot imagine this has an appreciable oxygen ingress rate over the course of a typical fermentation.

The partial pressure difference used for diffusion calculations is that of the diffusant, which in this case would be about 21 kPa, being nearly zero* on one side of the barrier and 21 kPa on the other. Assuming an area of about 0.3m2 and walls around 5mm, the stated rate of 32 ml / m2 / day comes out to an oxygen ingress rate about 62mg per day or 2.5 ppm per day for a 25 litre brew. Not a problem during fermentation but completely unsuitable for storage.

* figure 2 kPa per ppm DO2 but in most fermentations the DO2 is well below that.

 

[Lyrebird_Cycles]

Seems like using a butterfly valve to dump trub and collect yeast would be the main draw of this. It got me thinking, can butterfly valves take pressure? Do you think theres any way to attatch a butterfly valve to the bottom of a corny key and use it as a pseudo conical and serving vessel in one?

Brewery tanks always use butterfly valves. They're generally rated to at least 6MPa depending on seat material (the valves, not the tanks).