Keep Cut Onions Fresh: One Classic Storage Item Prevents Them From Going Bad Quickly

Onions, whether raw, fried, caramelized, or simmered, are a critical ingredient for building flavor. However, if you are prepping for a meal and have chopped, diced, or cut up too much of this bulbous veggie, storing it in the fridge in any old container (or no holder at all) can cause you grief. This is one of the many mistakes you might make when storing onions. That strong, lingering odor can spread and have everything in your appliance smelling and tasting like it. Enter the humble Mason jar. 

Onions are notoriously pungent, but this container, which was initially used for canning and can withstand extreme temperatures, is the perfect vessel to keep raw, chopped onions simultaneously fresh and the smell contained. Glass is superior to plastic because plastic will absorb smells. You want to start with a clean Mason jar that is free of moisture. Water can cause onions to spoil and become slimy, so a dry jar is key. You can line the bottom of the jar with a paper towel to absorb that liquid as an added precaution. Place the metal lid on nice and tight, and put it in the fridge. 

Cut onions need to be placed in the fridge within two hours of chopping, or they risk getting dry and growing harmful bacteria. How long will chopped onions last in the fridge? Raw ones, when stored in an airtight container like a Mason jar, will have a shelf life of anywhere between seven and 10 days. It could be a few days longer, depending on how fresh it was to start with or how you cut it.

How can you tell if your chopped onions have gone bad? The beauty of a glass container is that you can see just how fresh your pungent veggies are. If you see that they are mushy, slimy, or the color has changed, don't use them in your French onion soup or any other recipe. Pitch them. 

Since Mason jars are made of glass, you want to be careful not to drop them. Additionally, if you plan to freeze your jar of cut-up onions, make certain you have a freezer-safe Mason jar. If the sides are tapered or straight, it can go in the freezer.