I have a small server with growthcraft. Occasionally, such errors filled the console screen and some time later server crashed. Repeated few times.

That was caused by such kettles with wine. After destroying them errors stopped.

Deleting recipes and then even whole config haven't helped anyway.
Version is 4.2.0 (1.12.2)

I am having this same issue. I am using the brewing json default within a modpack.

Please post your JSON file and we can review it.

Sure,
https://pastebin.com/QMsWPWJh

Modlist:
https://pastebin.com/UN4t8GKU

Please attach your brewing.json. That error means that something is wrong with it. Using the default generated json does not produce this error.