The best way to store onions so they stay crisp might not be an option if you have an overabundance, but according to Patrick ...

After blanching, you should cool the vegetables, drain and cut them into appropriate sizes before freezing. Cut onion into dices 1 cm on a side. Remove strings of celery stalk and cut into 1-cm cubes.

When it comes to freezing onions, Ochs doesn't recommend it. "Freezing whole, raw onions isn't the best method if you're aiming to preserve their texture and flavor for later use," he says.