Only tried with stale berries but I can't seem to get it to work. Not 100% sure if it's just a problem with stale variants or if it applies to regular non-stale berries

Steps:

1. Have a mortar and pestle, a bowl and berries in your inventory (I had 10)

2. Click and drag the stack of berries onto the mortar and pestle. Zero feedback or lighting up of the mortar, it just doesn't register it.

(Inkberries at least still work, I suppose since they can't go stale?)