The Onion Saver works really well to contain odors and keep a cut onion fresh and moist, just like any well-sealed plastic container. But it's the shape that sets it apart for me. I can tell at a glance what's inside it without having to open the lid and the bright color keeps it from being lost in a crowded refrigerator. The Sur la Table website also mentions that it's a fun way to serve sliced onions at picnics.
Other things in its favor are that the Onion Saver is phthalate and BPA-free, which is not always the case with all plastics. It has often saved me from using plastic wrap and baggies, and it seems to keep onions fresher for a longer period of time. No mushy onion goo from a long-forgotten onion! And it washes up really easily.
There are also lemon, lime, red and green pepper, and tomato shaped containers. Truth be told, I don't use just onions in my onion container (its really great for avocados!) but it's still a really handy item. Plus, it makes me laugh every time I use it, and that counts for something.
The Onion Saver from Su la Table, $4.00.
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(Image: Sur la Table)