I am not at home and presently I don't have any airtight container. Most of the suggestion online are about using a airtight container.

Can't I use a bowl and cover it with plastic wrapper and then put it in refrigerator?

What piece of kitchen equipment do you regret buying? Why?

I bought a garlic masher. (I don't think it was anywhere near £26 when I bought it!) https://www.amazon.co.uk/royalvkb-VP303-370-Royal-Garlic-Crusher/dp/B000OW58D8/ It looks really heavy, but it actually isn't. I regret it because it's not nearly as much fun to use as it looks. It's safer than mashing garlic with a knife, and it's easier to clean than a press. But other than that it's not worth the money. The garlic cards (credit card sized bits of plastic with embossed letters) that you rub garlic over are better.