I think it might have something to do with the Useful Kiln mod, batch production reactions specifically

Making clay bricks out of peat results in iron blocks being made instead. While it's an easy way to get iron for building purposes, it feels kinda cheaty

Does it happen with vanilla reactions? It could be a result of interactions of two mods.

not sure if it's normal, but I sometimes get random iron products out of the craft whenever moss peat is used for ceramics (Ceramics Expanded is also installed). not sure if that's something that can be avoided or not. frustrating when I'm going for a weight 10 stoneware and get a random wieght 37 iron pot cluttering up my stockpiles

You are absolutely correct, it was in a separate file so I missed it. Thank you for the report!

Version 1.1:
- Fixed Kaolinite clay reactions by adding appropriate reaction class to KAOLINITE material.

You forgot to modify kaolinite, and with this mod every Porcelain creation interaction are locked.

I will definitely try the wiping thing. I have never done that. IT WORKED. Thank you! I had never thought to do that to fix mod issues. Now I know.

1) Make sure you select this mod on world creation (button MODS when creating a world).
2) If there's an issue, delete the mod from /data/installed_mods before starting the game so it reloads it.

I just tested it on the new world, and the reaction "Process peat" is definitely there.
Do you by chance have anything else in "data/installed_mods" folder, have you tried wiping it?
Any errors in errorlog.txt in the root game folder?

Sure, I will be glad to help, let me load the game.

Love the idea of the mod, however I seem to be doing something wrong. I select this mod and no other mod that effects the soil, stone, or clay reactions. However I then load in, find peat, collect clay and then do not find a reaction in either the kiln or smelter peat. I then tested this with being the only mod and it seems to still not work. Sorry to bother you, but could you advise for next steps? would it be better to add it in to the files like we used to do before steam edition?

I've put the name of the collection in front. But it's not a big deal, as you wish :).

"Industry - Peat and Bog iron" would be a better name for this