Salt’s Effect on Vegetables

When you use salt in the kitchen, yer a wizard (Harry)! 🧙

Salt of course makes vegetables more flavorful. But it also magically transforms them! You can use salt to have greater control over your ingredients. And when you have more control, you get the results you want. It’s like getting an 'Outstanding' on your O.W.L.s. 🦉

Salt Changes Things

Like salting meat ahead of time, salt draws moisture out of vegetables. How? The salt creates a higher ion concentration at the surface of the vegetable. Over time water travels from within the vegetables to the surface to create equilibrium. It’s a process called osmosis. The same thing happens in meat. But unlike meat, we don’t wait around for the water to get reabsorbed.

How do you salt vegetables in advance? It’s simple. Use about a teaspoon of kosher salt per pound of vegetables. Toss well and then let them sit for about 30-45 minutes. You can let them drain in a colander as they sit or press them with a towel to get rid of the water.

It is worth saying, that this happens for all vegetables. But you’ll only notice the difference in watery veg: eggplant, tomatoes, squash, zucchini, cucumbers, etc. 🍆🥒 🍅

But salting veggies ahead of time doesn’t just remove liquid. It also affects texture. Which is important to remember for the less watery vegetables too.

With less water inside, the cells lose pressure and start to soften. And that’s not all. The sodium ions replace the calcium and magnesium ions in pectin. Why does that matter? Pectin is what makes cell walls strong. 💪Removing the calcium and magnesium ions weakens them. This means veggies salted ahead of time are more tender—almost wilted—which has its pros and cons.

When You Should and Shouldn’t Salt Vegetables Ahead of Time

Salting vegetables ahead of time is a tool in your toolkit. It’s not something you should always do. You have to consider the final result you want.

Examples of When to Salt Veggies Ahead of Time

• Baked dishes—like casseroles, quiches, and tarts—are all delicious when packed with vegetables. But if you put tomatoes, eggplants, or squash in them, they can turn into a soggy bottom. 😉 Salting those vegetables ahead of time removes that excess liquid before you cook everything. And less moisture means less of a chance of a soggy bottom!
• Steam is the enemy of browning. When you roast or char a vegetable, you want as little moisture as possible. Browning won’t happen while water is in play because water can’t reach about 212°F (100°C). So getting rid of excess water is key for proper browning. It’s a must for watery veg like squash, zucchini, or eggplant.
• A salad isn’t just for delicate, leafy greens. Salting ahead of time is a great technique for tenderizing raw, hardy greens. Whether it’s Brussel sprouts or kale, you can shave and salt them in order to make them tender enough to eat raw.
• When deep-frying vegetables, if there is too much moisture, they can turn floppy instead of crisp. Why? Too much moisture will create steam.

Eggplant spotlight: Eggplant is full of air pockets. It’s what makes it so absorbent of cooking oil. But salt collapses those air pockets. It makes eggplant less absorbent, which means it will turn out less greasy in the end.

Examples of When NOT to Salt Veggies Ahead of Time

• Cabbage is a crunchy vegetable. 🥬 Slicing it thin and salting it makes it more tender. But sometimes you want to maintain that crunchiness. Never salt cabbage ahead of time if you need it as a crunchy topping like for tacos or pierogies.
• Mushrooms are largely made up of water. 🍄 And they also lack pectin. So if you salt them ahead of time, they lose a ton of water quickly. And a mushroom without water can turn rubbery. So wait to add salt to mushrooms until after they have started browning in the oven or pan.
• Tomatoes and cucumbers are two typical salad ingredients. And they are full of moisture! So if you salt them directly ahead of time and then add them to a salad, that moisture will pool at the bottom of your bowl. They can turn your salad from crispy to soggy. So be careful!

Where I learned this: The Science of Good Cooking, Samin Nosrat’s Salt Fat Acid Heat, and this America’s Test Kitchen Bootcamp video