Pfft. Another muggleborn thinking they have all the answers.

 

Just came here to say "mAgIc"

 

For many of them I imagine thier house elf handles it.

 

I'd imagine that most wizards have a pantry of sorts for food that they routinely apply refrigeration charms to. 'Stasis' charms just sound like entirely too much effort, given how complicated magic that affects time seems to be.

 

Might make an interesting way to differentiate between wealthy and non-wealthy. The non-wealthy have a cold room/shelve which they (or someone they know, depending on individual talents) can charm to stay cold. The wealthy have a room or shelve charmed with fancy time magic that holds everything in some form of stasis.

Functionally there's no major difference, as the cold shelf achieves a sufficiently similar result as long as you vaguely plan what you're buying and when you're going to use it. But you can see some clever Charmer upselling the idea to a well off Ministry official or business owner.

 

There would be benefits and downsides to both, I think. Imagine being able to preserve freshly baked bread in an unaltered state for months after the creation of it, but then having unpleasantly warm, but well preserved milk. If the charms for the preservation of food were taught at Hogwarts, I'd wager that Hermione would have known them, which suggests to me that they're a more specialised form of magic, or are unsuited to travel at the very least.

 

What about vanishing and de-vanishing (conjuring?).
If you can "find" again objects that have been vanished, why not food?
Bake your bread, vanish a fresh loaf. Then conjure it again later... fresh bread magically preserved!