Maybe you own a fridge; maybe you don’t. If you do, you, at some point, have definitely crammed leftovers in there. After reclaiming them, they might have had their flavors bleed together with the other food in your fridge. Honestly it may or may not have been a good time–we’re not entirely sure what you were indirectly blending in your fridge. So, what causes these your foods to absorb other flavors and blend together?
What Happens to Your Leftovers?
Some leftover food just kind of gets… Gross in the fridge. Having lived with a fridge for some amount of time, you’ve probably developed some sense of what you definitely should not stick in the cold-box. Sushi, for example. Never do that.
We also know that pretty much any leftover you put in your fridge has an expiration date. The longer stuff sits unconsumed, the more gross it can get.
But conversely, there are some things that might improve from (at least a little) time spent in your fridge. Leftovers with garlic, onions, or other foods that are considered aromatic can get an added boost from time spent in a refrigerator. Without diving into the chemistry of it, heat is a good way to get flavorful reactions going–this is why aromatic flavors persist when cooking, or even after you’ve pulled food out of the microwave.
The same kind of stuff happens with starches, or the more gelatinous parts of meats (like tendons). This gelatinous stuff melts while you cook, and easily kind of gels around other food. However when cooling (especially with starches), these gels can re-harden into their original, more solid forms. Since they’ve wrapped around other foods, those flavors get trapped between molecules and stuff when they’re reheated for your consumption.
Hence, the flavors in some reheated foods might even be stronger. Sometimes people claim there’s more umami flavor in their leftovers, but that’s probably a psychology thing. Flavors blend together in the fridge to make them more well-rounded, which may make the umami flavor more noticeable.
Further Reading: What Is Umami Flavor?
Why Do Foods Absorb Flavors in the Fridge?
So we’ve talked about your individual leftovers tasting different, but what about that time you threw an onion in the fridge and then everything tasted like an onion?
Luckily for you, you’re not crazy. Onion is a crazy aromatic food, which, as we covered before, easily interacts with other food. And it turns out, it can do this even in the absence of heat.
Fatty foods and starches do that gel-y thing in the fridge, making them very susceptible to the heavy aromatics of things like onions and garlic. Things without much flavor are also popular candidates for absorbing flavors, think bread and apples too.
Does This Explain “Freezer Smell/Taste?”
Given that the foods giving off the most transferable flavors also smell strong, the answer to this question is probably yes. Honestly, the smell/taste coming out of your freezer is probably caused by a combination of your aromatic foods and the slight aromatic properties of all your other foods. Or your antifreeze smells bad or whatever.
In summation, if you want to keep your foods from crossing over between each other, keep aromatics quarantined and use airtight seals on your leftovers. Or find a way to reduce odors in your fridge.
It’s organic chemistry time! See if you know what kinds of molecules are/aren’t aromatic here. Might help with the fridge.