What it is about cooked spinach that makes your teeth feel all filmy and icky? This article explains the chemical reaction that creates this annoying side effect—and how to avoid it.

A set of fake teeth with googly eyeballs on top with a piece of spinach between two teeth to illustrate why spinach makes my teeth feel filmy.

Why Does Spinach Make My Teeth Feel Filmy?

Dear Never Cook Naked Guys: Whenever I eat spinach, cooked or fresh, I get a filmy feel on my teeth. What is that? Is there a trick to cooking spinach to minimize the effect?—Gritted Teeth

Dear Gritted Teeth: You’re worried about teeth that feel filmy? We’re worried about gross green flecks in ours.

Here’s the deal: spinach is high in oxalic acid. When the leaf’s cell walls are broken down, the acid combines with naturally-occurring calcium to make calcium oxalate—essentially, little crystals. Voilà your filmy, gritty teeth.

You have three potential solutions:
1. Wilt spinach quickly over high heat. Do not “cook” it. You’ll still get a little grit, but not as much as (blech) canned spinach.

2. Eat raw spinach. If you chew spinach salad fairly quickly, you don’t have to worry much about this chemical fandango. But keep a toothpick handy to avoid that nasty aforementioned spinach-in-your-teeth situation.

3. Switch greens. Turnip greens, mustard greens, and collards are relatively low in oxalic acid. You can chow down and not worry about film or grit.

Oh, by the way, oxalic acid does one other thing: it inhibits the absorption of iron. Popeye never got as much as he thought. Seems like another reason to switch from spinach to another green to us.

Our very clever, very clothed Never Cook Naked columnists are at your disposal, able to troubleshoot everything from questionable table etiquette to tricky cooking techniques (as well as, natch, proper cooking attire). Curious to learn more solutions to culinary conundrums? Just ask! Drop us a comment below.

Originally published May 14, 2013.

About Bruce Weinstein | Mark Scarbrough

Bruce and Mark are award-winning, international best-selling cookbook authors with thirty-six published cookbooks and over 1,000,000 copies of their books in print. Bruce and Mark have published on topics as diverse as ice cream, ham, barbecue, goat, and vegetarian main courses. They are masters of the air fryer with The Essential Air Fryer Cookbook (2019), and The Instant Pot with The Instant Bible (2018) and The Instant Pot Bible: The Next Generation (2020).
Their You-Tube channel Cooking with Bruce and Mark offers hours of delicious fun and their podcast Cooking with Bruce and Mark reaches 10s of thousands with their culinary antics.
When they are not in the kitchen, Mark teaches lit classes and runs book groups throughout Litchfield County and online while Bruce teaches knitting and designs knitted patterns for both men and women. Find out more about what they’re up to at www.bruceandmark.com

Hungry For More?

Hungoevr, er, Hangover Cures

You may not be thinking this now, but with this stash of hangover fixes both tempting and therapeutic, you can snatch hope from failure, triumph from despair. Milton Crawford explains.

How to Store Holiday Cookies and Candies

Savvy tricks that ensure your Christmas creations look and taste as stunning as they did the moment you finished slaving over them even weeks after the fact. Let the holiday spirit linger!

Leave a comment

Your email address will not be published. Required fields are marked *