German Brewing

I had my own made custom, they are made from lexan flexible shatter proof see through. It's used in masks for fireman breathing apparatus, it will withstand 500°f without an issue, should be easy to have a 3/8 " thick piece custom cut.

The only worry with plastic being the plasticizers used in their manufacture can leach out especially when heated. Adipates, phthalates, sebecate etc. are not things I want in my beer.

I have not had any noticeable aromas or flavors YET but I will keep it in mind to be looking out for them. If I do detect any I'll be having custom stainless lids made.

I have to admit to side with Blisch on this one.

Be very careful with the plastics involved. In Germany we had platsic kettles deemed food safe. Later studies showed deposits backtracked to these kettles in children's kidneys. IIRC that was in the mid-90s. Arguably, nobody did a blind tasting and a thereof impeding vivisection of the subjects involved.... (like some hobby brewers seem to demand as irrefutable proof ), but the sheer possibility of this being a problem makes stainless steel a sensible proposition.

Now, for those who conclude this is humbug, well, never mind my musings. After all, you are consuming most of it and will be the monuments and testament to these findings. These were never put to a human trial, so thank you for volunteering.

Mine aren't mash caps though, they are custom made lids totally sealing the system from outside air. That might make a difference

For your viewing and opinion , the white lid also has a small motor attached to the top of it sealed with a paddle attached for mash agitation