Minor issue but shouldn’t be possible. Rotted stalks should be excluded.
you can craft anyhting from rotten ingridients but problem is that rotten starch turn into normal flour same going for anything rotten going into non perishable food.
You can craft pemmican, aspic, fruit leather, and I thought anything that turns grey after crafting, from rotten ingredients, I thought.
Sigh, I recall dirty cloth used to work in crafting, but sadly they don’t now.
Basically for food (and chemicals), you can craft rotten things and remove the rot if the result is an item that does not expire. Like rotten tainted meat into dehydrated tainted meat, or mutagen. Or turning rotten milk into powdered milk, and turning that powdered milk into fresh milk.
This is how I keep mah meat. It does however prevent me from making glazed tenderloins.