Can You Slice Onions the Day Before?

Food prepping can be tiring. This is especially true if you have a lot of ingredients in something that you are planning to cook.

If you are thinking of cooking a complicated meal after a long day at work, you might have to decide whether or not you can make this meal due to time constraints related to getting the ingredients together for the recipe.

This is one of the questions that people often have about cutting onions in advance. Onions are tough to prepare because of the related tears and runny nose that they cause. They can make your hands smell like an onion for days.

If you want to prepare all of the ingredients for a recipe the day before, including the onions, you might be wondering if this will affect the flavor of the completed dish.

If you want to learn more about slicing onions the day before you need them for a recipe, read on!

Sliced onion on a wooden cutting board

What Happens to Onions if They Are Cut in Advance?

This is one of the things that gives many people pause about cutting onions in advance. Due to a chemical reaction, onions release enzymes that are called alliinases as they age.

This means that this sulfur-containing chemical compound can impact the taste of the onion as it ages.

For onions that are cut the day before, you can expect them to have a more pungent taste and smell. Some cooks counteract this change by rinsing the onions before they are cut and this can help some with the overall aging process of the onions.

You might also only cut the onion into rings and then chop it up further the day that you are going to be cooking with it. The less that the onions are cut and the less that they come into contact with a knife during preparation, the sweeter they will be.

The fewer cuts in the onion, the better the overall flavor. This is why it is common to smash onions to remove the peel rather than cutting it off.

Freshly diced onions will always have the sweetest and lightest flavor, which is why it is often best not to cut them well in advance.

There might be reasons that you want your onions to be more pungent and in that case, cutting them in advance is the right choice to make.

There are limited circumstances where this will apply, but you might find some application for this strong onion flavor in some dishes.

Can Onions Get Too Old to Eat Safely?

Onions are fairly resilient veggies, even when cut up, but they can get to a point where they are not very palatable.

You should never cut up an onion any more than a day in advance if you want to cook with it, or the flavor will be too strong to be enjoyable.

As with any vegetable, do not eat any onion that shows signs of mold, browning at the edges, or other symptoms of going bad.

Onions that are more than a day old will likely be too strong to be enjoyed but they will not be harmful to your health. You will find that the older an onion gets, the less enjoyable the taste is.

This applies to every variety, but red onions, in particular, can be very strong and lacking in good taste properties after a day of being cut up.

Sweeter onions might be more forgiven when chopped up early but they also tend to go bad quickly and get brown and squishy. There are a whole host of reasons not to prepare any vegetables any earlier than a day in advance and food safety is one of these reasons.

What About Onions Used in Complex Dishes?

If you are cutting up onions for use in a more complicated dish, there have been studies done that have shown that this change in the flavor of the onion is not that noticeable when buried beneath other flavors.

You can also adjust for the aging of onions that are used in complex dishes by including fewer of them and helping to balance out their strength in the final product this way.

Some varieties of onion, such as red or white, will definitely age more rapidly and have a more robust flavor and smell when cut in advance, so you might want to lean toward other varieties if you think that you will need to cut your onions in advance.

When making onions for use as toppings for chili and other dishes that often have a strong onion flavor associated with them, cutting onions in advance might actually improve their flavor for your needs.

For all other dishes, it is wise to cut back on the amount of onion that is included in the dish to compensate for the increased sourness and strength of the onion flavor when they have aged for a day.

Onions Are Best Chopped The Day That You Are Cooking a Dish

Overall, onions are best when they are chopped up the day that they are needed for a dish. The good news is that you can often cut up other veggies that you might need without impacting their flavor.

This means that onion and garlic might be the only items that you have to cut up as you are preparing the meal that you have been wanting to make.

Onions might not be pleasant to cut up or work with until they are included in your favorite dish, but making sure that you cook with them when they are at their freshest can improve the overall flavor of your dish greatly.

This is true of all varieties of onions and you should consider this the best rule of thumb for dealing with onion chopping when you are in the kitchen.

Chopping your onion the day that it is needed will yield the best overall flavor and texture for your dishes that include onion.

Leave a Comment