Why Do Smells Like Onion and Garlic Stay on Your Hands After You Wash Them? People Weigh In.

If you’ve done any cooking, then you’ve probably noticed that certain foods you prep…linger. The smell of onion and garlic, for example, can be scented days after you’ve made the meal, after you’ve washed your hands multiple times and even showered – but why?

This is the perfect query for Reddit’s No Stupid Question forum, and I don’t know about you, but I’m super pumped that someone actually asked it.

How do certain smells like onions stay on your fingers for so long, even after you wash your hands repeatedly?
byu/CanadianOldDutchOven inNoStupidQuestions

Let’s hear what these 11 Redditors said in response then, hmm?

11. The technical answer.

When cut open, onion cells release enzymes which convert its amino acid sulfoxides into sulfenic acid, the effects of which can be felt immediately.

That same chemical adheres to skin and stays there, sometimes for days, until something neutralizes the acid. Soap typically won’t do the trick.

10. Using stainless steel can help take it away.

The sulfur from the onion, garlic or fish is attracted to—and binds with—one or more of the metals in stainless steel. Formation of such compounds is what makes stainless steel stainless. Onions and garlic contain amino acid sulfoxides, which form sulfenic acids, which then form a volatile gas—propanethial S-oxide—that forms sulfuric acid upon exposure to water. These compounds are responsible for burning your eyes while cutting onions, and also for their characteristic scent. The sulfur compounds bind to the steel—efficiently removing the odor from your fingers.

So, next time you find your fingers and hands smelling from fish, onions or garlic, don’t reach for the scented spray; grab a stainless steel knife. Take care, though, to wipe your hands on the flat side, and your limbs will be scentless in no time.

9.  This smell isn’t so bad, though.

Oranges too; gets in the creases of your hands.

8. Get yourself some stainless steel.

So because the smells are caused by sulfur, it turns into sulfuric acid when you wash your hands with water. So the stainless steel basically binds to the sulfur molecules and thus, “washes” away the smell on your hands.

I got a stainless steel soap from the dollar store and they had this explanation on the back of the packaging in terms of the smells being negatively charged ions and the stainless steel being positively charged, so basically positive attracts negative and zoop, your smell goes away.

But I was terrible at Chemistry and last I studied that shit was in 2014, so I don’t know if this ion business is legit. The first paragraph is the actual explanation for sure, though.

7. Because sticky molecules.

Same reasons why some stains are difficult to remove while others aren’t.

The adhesive force between your hand and the particles are strong and possibly stronger than the cohesive force between the particles.

Basically some molecules are sticky.

6. It can happen to your kitchen, too.

If your kitchen smells funky and it’s not the trash or the fridge, give every stainless steel appliance a rub down with salt mixed with baking soda (as long as it’s not a pan), then rinse with warm water. The smells should go away.

Typically kitchens retain scents for reasons I don’t know but this pretty much always works and in the worst case scenario you’ve cleaned the kitchen a little more than you needed to.

5. Moisten. Ugh.

They don’t if you keep some baking soda next to the sink.

Moisten your fingers and rub them with the baking soda after working with onions or garlic and poof, smell gone.

4. The tricks might not work, though.

Most likely not. Sulfenic acids bond covalently to the proteins in your skin, causing them to be released slowly. There isn’t much you can do about that except wait. The chemicals you’d need to reverse that aren’t generally available to consumers/are too harsh to put on your skin.

Interestingly, a lot of lachrymators (compounds that make you tear up) work this way, including some types of tear gas. Generally, highly reactive compounds are dangerous, so your body reacts strongly and tries to get them out of your eyes as soon as possible. Onions exploit this reaction to try (unsuccessfully) to get you to not eat them.

3. Soap doesn’t solve everything.

I see a lot of responses on how to get rid of the smell but not so much on why it lingers.

The reason it lingers is because soap is a surfactant that can remove some things, but it doesn’t work as a solvent for everything.

It’s why lemon juice or baking soda work for cleaning: acids and bases will dissolve some things.

Various foods will and will not dissolve in various solvents.

2. Props, indeed.

Jesus !! I never thought there was an actual answer to that question, I’ve always thought that’s just how things work, and have accepted it cause that’s how the things work

Props to the guy who asked the question, and the person who understands the answer to that should give it a shot and try to apply to SpaceX.

1. I need the answer to this one next.

Diesel is the one that gets me.

What’s the neutralizing yin to that yang on my hands?

If you didn’t know, now you know. Pumped!

Are these answers correct? If you need to fix some details, our comments are open!