The description says:
Up to ten berries appear in your hand and are infused with magic for the duration. A creature can use its action to eat one berry. Eating a berry restores 1 hit point, and the berry provides enough nourishment to sustain a creature for one day.
The berries lose their potency if they have not been consumed within 24 hours of the casting of this spell.
How should I read "up to ten"? Should I roll d10, or does it depends on the spell slot, or can the caster decide how many berries it creates? If it is up to the caster, I can't think of a good reason for creating less than ten.
Best Answer
Since the spell does not provide a roll, it is left to the caster's discretion how many Goodberries are created.
Producing less than ten: Aside from roleplaying factors (which are nearly unlimited), Goodberries are magical for the duration of their existence and are therefore detectable. If one was trying to remain undetected, the spell allows you to produce only what you require.