I tested four different cooking methods to see if I could eliminate “spinach teeth” once and for all.

Alex Loh
November 06, 2020
Each product we feature has been independently selected and reviewed by our editorial team. If you make a purchase using the links included, we may earn commission.
Advertisement

If I had to create a list of my favorite vegetables, spinach would definitely be at the top. Not only is spinach packed with nutrients like calcium and potassium, but it’s also been associated with impressive health benefits like lowering your blood pressure and being good for your skin. Plus, spinach can be used in endless ways, from smoothies to salads to a simple, delicious side dish. But the one downside to spinach? The weird, chalky feeling it can leave on your teeth after you eat it.

That problem (aka “spinach teeth”) is common for people who consume the leafy green. And it turns out there’s a scientific reason behind that weird feeling: Oxalates. According to Harold McGee, author of On Food and Cooking: The Science and Lore of the Kitchen, “Oxalates are various salts of oxalic acid, a waste product of plant metabolism found in a number of foods ...The sodium and potassium salts are soluble, while the calcium salts are insoluble and form crystals that irritate the mouth and digestive system.” 

In layman's terms, the undissolvable calcium salts get left behind in your mouth and leave a coating on your teeth. Don’t worry though, the oxalic acid won’t do damage to your teeth (although too much oxalic acid can lead to kidney stones). And while that’s good news, it can still be uncomfortable to eat cooked spinach knowing that your mouth will feel kind of funny. So, to try and combat spinach teeth, I tested four different cooking methods to see if I could lessen the reaction. Here’s what happened:

4 Methods for Cooking Spinach

Test #1- Steaming

A study in the Journal of Agricultural and Food Chemistry conducted an experiment that tested the level of oxalates in vegetables after they were steamed, boiled or baked. While test results for insoluble oxalates varied, I was interested to try the method out for myself.

Left: The spinach while it cooked | Credit: Alex Loh
Right: The result after cooking | Credit: Alex Loh

I used 6 ounces of water to about three handfuls of spinach, and cooked it over medium heat with a lid on the pan to create some steam. The spinach wilted after four minutes. I drained the excess water before eating the spinach. 

The result: Good. While I normally feel the crystals on all sides of my teeth, eating this spinach only left that feeling on the backs of my teeth. That’s definitely a win in my book!

Test #2- Lemon Juice

I’m not a huge fan of lemon, so I was a little hesitant to try this method. But, according to Jim Correll, a professor of plant pathology at the University of Arkansas, the ascorbic acid found in lemon juice can help dissolve the oxalic acids in spinach.

Left: The spinach while it cooked | Credit: Alex Loh
Right: The result after cooking | Credit: Alex Loh

I used 2 ounces of lemon juice to about three handfuls of spinach, and cooked it over medium heat. The spinach wilted after five minutes and turned a little yellow, presumably due to the lemon juice.

The result: OK. Turns out, 2 ounces of lemon juice was way, way too much. The spinach was so tart it made my mouth pucker. But aside from my acidic blunder, I did find that the crystals on my teeth were allocated to just the backs, and the feeling was nowhere near as intense as usual. This is a win for people who like lemon with their spinach. For me, I would definitely try this test again, but with less lemon juice.

Test #3- Yogurt

I was most skeptical about this method, mainly because I got the suggestion from a Reddit thread. However, a study published in Food Chemistry conducted an experiment where calcium compounds were added to raw spinach and resulted in reduced oxalates, so I was curious to see if the same idea could be applied to cooked spinach and insoluble oxalates.

Left: The spinach while it cooked | Credit: Alex Loh
Right: The result after cooking | Credit: Alex Loh

I tried it with 2 tablespoons of plain yogurt to about three handfuls of spinach, and cooked it over medium heat. The spinach wilted after four minutes but the yogurt separated. 

The result: Awful! First, the broken clumps of yogurt led to a very unappealing visual. The yogurt did nothing and the spinach made my whole mouth feel dry and covered in the crystals.

Test #4- Boiling

The aforementioned study from the Journal of Agricultural and Food Chemistry mentioned boiling vegetables as another method for reducing oxalates, so I was hopeful about this test after the moderate success of the steaming method.

Left: The spinach while it cooked | Credit: Alex Loh
Right: The result after cooking | Credit: Alex Loh

I filled a medium pan halfway with water before adding about three handfuls of spinach. After three minutes on a medium-high boil, the spinach wilted. I drained the excess water before eating the spinach.

The result: We have a winner! While the crystals didn’t disappear completely, they covered a much smaller surface area in my mouth compared to the other results. And the lingering feeling of spinach teeth, which usually lasts until I brush my teeth, lasted for far less time than normal.

The Bottom Line

While no one method completely removed the feeling of spinach teeth, it was still fun to try out the different methods. Although I’ll stay far away from yogurt when cooking spinach in the future, I’ll definitely use the boiling and steaming methods again whenever I want a healthy side of cooked spinach!