Simply put, will continuously simmering vegetables for days, even up to a week or two, in a perpetual stock lead to unexpected or unwanted results?

Since even the longest stock recipes I know don't take more than a day to make, I assume flavour extraction will stop after a few hours but does cooking veggies beyond that point generate off-flavours?

I've also looked up safety concerns of perpetual broths; in this case, since it's a vegetarian one consistently kept at a simmer to which I will regularly add boiling water, I don't think it will be an issue. I'm still new to food-science though so I might have missed something there.

Some answers, for example this one by barbecue or that one by jeabp, partly answer this question, however, I don't think it's specific enough to render this one a duplicate.

  • What different answer do you expect? It's already mentioned in the linked questions: "I think the issue is that there's a limited amount of the aromatic compounds which produce the desired flavor, and over time, these tend to evaporate." so why simmer further?
    – Luciano
    Commented Jul 1, 2020 at 19:28
  • 1
    To me, this is a duplicate...any aspect that does not cover (will it lead to unwanted results) is probably a matter of opinion.
    – moscafj
    Commented Jul 1, 2020 at 20:41
  • @moscafj That question does say "I'm asking explicitly about one unchanged stock: a pot of bones in water, optionally some spices and mirepoix" whereas mine is about a perpetual vegetable stock and the effects of simmering for a long period of time, not how long to simmer.
    – Hugo
    Commented Jul 1, 2020 at 20:45
  • @Halhex, I hear you, but the first answer pretty much covers your issue.
    – moscafj
    Commented Jul 1, 2020 at 20:47
  • @Luciano That answer does mention the loss of flavour over time, however, it does not talk about possible adverse effects of keeping it on a simmer for longer, such as unwanted flavours.
    – Hugo
    Commented Jul 1, 2020 at 20:49