Thanks, that page also links to Wonderbag which is far more practical to DIY. The branded ones are rather expensive (although to be fair that price includes the charitable contribution).
In any case wrapping a stockpot in silicone (to protect the fabric) and then even more insulating material should be straightforward.
SoleInvictus@lemmy.blahaj.zone 1 week ago
Ooof, the blurb about haybox food safety needs to be corrected. Some microbes create secondary metabolites which cause illness. Reboiling won’t destroy them.