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Salads are very popular, especially during the summer. Many have a similar question to this: how long can a salad last, though, especially if it gets left out overnight?
A salad can only last outside of the refrigerator for 2 hours. Putting the salad in a refrigerator can keep the lettuce fresh for a longer duration. When any sort of dressing is added to the salad that time is even less than 2 hours because the wilting process accelerates and makes the salad less desirable.
Dressing affects how long a salad can last, but it does not affect it in the way in which one might think. The reason a salad with dressing gets soggy may be almost the opposite of the reason you may think.
How Long Can a Salad Stay Out?
A salad, on average, can stay out of a fridge for about 2 hours before it should no longer be eaten.
When an event is held outside on a hot evening, you may notice that even though it is kept covered, lettuce is not as fresh after the event is over.
There may be a salad bar where each ingredient is kept separate from the others, so nothing has touched the lettuce to ensure it stayed crispy, but inevitably the end of the night rolls around and the salad, if there is any that is leftover must be tossed because no one wants wilted lettuce.
Besides the fact that it wilted, after two hours, there could be bacteria growing or bugs that have gotten to it (if the event is outside), especially if it has had dressing.
What Effects how long a Salad Lasts?
One of the main contributors to the whithering of salad is heat. When lettuce is left out of a fridge, it can begin to wilt because the water content of the leaves begins to dry out. Lettuce is often kept refrigerated for this reason. Not many people desire eating wilted lettuce, so keeping it in the fridge is a good idea.
The main concern about how long a salad can last refers to what toppings are included on the salad.
Contributors may include cheese and meat if they are included. Another contributor is something that can make the entire salad bad all at once. A major contributor to the decay of the lettuce leaves is the dressing.
When you add salad dressing to a salad, the lettuce leaves begin to wilt at a much more accelerated rate than previously.
How Does Dressing Impact a Salad?
It may sound odd to hear that the watery part of the dressing is not what causes the lettuce to get all wilted in your salad, but it is quite true. The dressing does affect how long a salad lasts but not for the reason you may think.
In salad dressing, there is one crucial ingredient that is added to the dressing that affects the way it tastes. This crucial ingredient is none other than…salt! It may be crazy to think that the thing making something wilt is a dry ingredient, but there is a reasonable explanation for this.
Have you ever had so much of a salty thing, like potato chips or popcorn, that your lips began to hurt because they were dry? Or have you ever realized that after spending a lot of time in the ocean that you needed to put on a ton of lotion to make up for the dryness your skin began to experience? Salt draws moisture from what it touches. The salt in the dressing does the same thing as the lettuce in the salad!
When the dressing interacts with the lettuce, the wilting process begins. Lettuce will naturally experience wilting over time since that is what lettuce does, but salad dressing speeds up the process drastically.
Dressing draws out the water from the leaves, and after the water is drawn out of the leaves of the lettuce, it cannot come back. When the lettuce leaves no longer have water, they begin to wilt. After lettuce has wilted, it is no longer as good as it was before.
Different Dressings on Salad
Many different kinds of dressings can be used on salads, so testing each type of dressing and the effect it has on lettuce leaves is important to ensure you do not have wilted lettuce. It is also good to know how quickly the leaves will wilt depending on the dressing you use. If you use dressing only for the flavor, it may be beneficial to know how long beforehand you can add it to your salad.
The table below demonstrates what happens to different kinds of dressing when they interact with lettuce leaves. The experiment’s explanation can be found by following this link.
|Type of Dressing Used||Wilted||Soggy||Crisp|
|Oil then Vinegar||X|
|Vinegar then Oil||X|
|*Vinegar, Oil, and a little Mayonaise and Mustard||X|
According to the data, when oil was applied almost directly to the lettuce, it played a large role in making the lettuce start wilting. The leaves of the lettuce did not react the same way when the vinegar was applied first, which is quite interesting.
Ranch, a common salad dressing was not included in this experiment, but it would have most definitely caused the leaves to wilt quickly simply because of the amount of salt that is used in making ranch. On average, ranch dressing has around 328 mg of salt per serving.
Just for comparison, an 8-ounce bag of potato chips has 18 mg of salt. The average person does not use the serving size, though, if they are using dressing, so the lettuce leaves are sure to wilt very quickly.
There can be many indicators letting you know when to throw out a bad salad. Such indicators include the color of the lettuce, the smell of the lettuce, and the texture of the lettuce. Using your senses, you can decide if the lettuce portion of the salad is good to eat anymore. If the lettuce is brown, soggy, and smells off, it is time to throw it out.
A salad can stay out of the fridge for around 2 hours, depending on how warm it is. If you are outside, the salad will wilt faster in the summer than perhaps inside by the A/C.
The addition of salad dressing will also affect how long the salad can remain outside of the fridge. Knowing how long it will take for the leaves of the lettuce to wilt after putting on salad dressing can, ultimately, save your salad.