Science: When to Add Salt During Cooking—and Why (It Makes a Huge Difference)

What's the role of salt in cooking? Is it important to add it at certain times? Most recipes (and culinary schools) advise seasoning food with salt early in the cooking process, not just at the end. We decided to investigate this conventional wisdom to see if the timing of seasoning makes a notable difference.

EXPERIMENT

We roasted carrots and prepared beef stew in two ways: For one batch we seasoned the dishes at the very beginning of cooking and, in the case of the beef stew, also when we added the onions. For the other batch we withheld all the measured salt in the recipes and added it at the end.

RESULTS

The roasted carrot samples were drastically different from one another. Those seasoned before roasting, with 1½ teaspoons of salt, were properly seasoned and flavorful throughout. Meanwhile, the carrots seasoned with the same amount after roasting were seasoned only on their exteriors and also tasted far too salty.

When it came to the beef stew, when we salted the meat before cooking (with 1½ teaspoons of salt) and seasoned the onions (with ½ teaspoon of salt) when they went into the pot as directed, the stew and particularly the meat itself were more evenly and deeply seasoned than those in the sample salted only at the finish. Furthermore, as with the carrots, the stew's gravy tasted far too salty when the salt was added at the end.

EXPLANATION

We know that salt penetrates food slowly when cold. (In a previous experiment, we found that it took 24 hours for salt to diffuse into the center of a refrigerated raw turkey.) While the process is faster during cooking—for example, our science editor noted that the rate of diffusion of salt into meat will double with every 10-degree increase up to the boiling point—it's still not instantaneous. Furthermore, salt penetrates vegetables even more slowly than it does meat (this is because the salt must cross two rigid walls surrounding every plant cell, while the cells in meat contain only one thin wall). Adding salt at the beginning of cooking gives it time to migrate into the pieces of food, seasoning them throughout. Meanwhile, if you add salt only at the end, it provides a more concentrated, superficial coating that immediately hits your tongue.

TAKEAWAY

For the most even seasoning and well-rounded flavor, we strongly encourage seasoning foods early in the cooking process as we direct in our recipes. However, if you forget, do not make up for it by simply stirring it all in at the end. Instead, start with a very small amount of salt—we used a mere 8 percent of the original amount of salt for the carrots after roasting (⅛ teaspoon versus 1½ teaspoons) and 31 percent for the beef stew (just over ½ teaspoon versus 2 teaspoons)—and then taste and season further as desired. On the flip side, if you are watching your salt intake, you could wait until the end of cooking to season your food, knowing that you'll be able to get away with a lesser amount.

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[BradiKal]

if you had told me the reason to salt food before cooking at the beginning of the video it would have diffused into my brain more quickly and completely

[teitake]

Would you do a video on the timing of seasoning with other seasoning materials?
In Japan, it's a common knowledge to season in the following order: sugar, salt, vinegar, soy sauce (and other sauces). I heard that the reason for the sugar being the first is because it has the larger size of molecules compared to salt. 

[ThomasLoughney]

Great video.   Thanks....I have noticed that effect also when cooking, and with other spices also. The penetration of flavor into the food is one reason stew always tastes better "tomorrow". Anything made using seeds, like caraway, anise, need extra time to develop flavor. Not suitable for microwave instant cooking.  Thanks for the tip.

[CorneliusSneedley]

The owner of a local restaurant said they don't salt their food during the cooking process because the first thing most people do anyway is salt it even before they taste it. Which, I suppose is often true, but to me their food just didn't taste good whether I salted it or not. I haven't been back.

[Kenchinito]

I love videos like this. Straight to the point, no bs involved.

[kutrabilada]

I learnt from Sarah Moulton that beans should not be salted until they are cooked. The tip did help me. If salted early they remain hard in the center.

[Law]

The right amount of salt can make or break a dish, I've learned this the hard way.

[__seeker__]

thank you for making this video. I can show it to some of my friends who watch me cook and look shocked at the amount of salt I add to dishes in the beginning. I've tried to explain it to them, but have years of cooking experience without the scientific knowledge of WHY I know I'm right. I just do what I know works and know that it's the right way. of course, when they acrually eat the food, they seem perplexed thag it doesnt taste too salty. cooking down onions without salt in the beginning also takes forever and produces a much less desirable flavor. when salt is there at that stage, it pulls out the water, thus making them cook quicker and sweeten more robustly.

[stephw]

I love this explanation! Thank you! I try to not use as much salt, but my food, while well-prepared, sometimes lacks that depth of flavor. I’ll think about this when I make supper tonight. Again, thank you for the post! 🥰

[Thecriticguy]

I managed to find this out through various attempts at trying to improve my own cooking. Adding about half or most, sometimes just gradually, and topping off at the end with a little greatly improves the flavoring. This is the same for most seasonings including liquids.

[arlenepadden]

One more reason to love ATK and CC content! Great job!

[icychap]

Outstanding video! Great information, concise and comprehensive. Thank you.

[arande]

Finally. I see all these recipes around the internet but I don't understand why they are doing what they're doing and that makes it hard to do my own recipes. I suppose there are some food science textbooks out there I can check out.

[flips]

Yikes. I'm a tad disturbed by the listening comprehension of some of the people in here. It's fine that people are concerned with their sodium intake--regulating sodium levels is very important in managing cardiovascular health, amongst other things--but that wasn't the point of the video at all. It was simply that the time in which salt is added during the cooking process produces noticeable effects on the final product. I thought they made it pretty clear that adding salt at the end (even at reduced levels to compensate for being superficially concentrated) was not an even substitute, as the main idea was how to produce more well rounded and deeper flavors. Not "hey guys, here's a great diet tip to reduce your salt!" 

[Jeremyb]

I am curious how salting at different times can affect vegetables in particular. I have heard that while sauteeing onions or peppers, salting them during the process helps them release water and caramelize better. Also, I have noticed that when I boil fresh green beans (on stove or instant pot) that if I salt them before hand they tend to come out mushier... but if I salt them in the end, they have a nicer texture... not quite so mushy. I don't know if there is science behind this or simply my own experience, but it seems to be pretty consistent in the results.

[AGC]

Interesting. Makes perfect sense. What I've been doing (also adding a little at the end to "fine tune" the taste. DOES make a difference. Good tip. Many home cooks might not be aware of this.

[armandopina]

thank you Mr Souza. now I know why my refried beans came out so salty this morning.

hope to see you more on TV.

[nickhill]

Salty flavour aside, does salting actually change the flavour of the other components of the food? I think it does. I find onion caramelises to a sweet flavour when salted, but tends to burn when not salted. Salted butter is a completely different product to unsalted butter. Take unsalted butter, you can never add salt to make it taste like salted butter. I hoped this video would investigate this phenomenon.

[gavlatennis]

Very useful reminder and guide. Thanks for uploading.

[gronkgrunk]

Very good explanation. I will keep this lesson in mind when i cook.