"Don't salt lentils while cooking": true or myth?

Question

We've all heard the advice: don't add salt when cooking lentils, because they'll toughen or not become soft or variations on that theme. For example, on lentils.org:

Be sure to season with salt after cooking – if salt is added before, the lentils will become tough.

The thing is, the same advice is given for basically all dried legumes, but Serious Eats debunked that - at least for beans (specifically, cannellini beans). But lentils aren't much like beans, neither in size, cooked texture, nor even really in cooking processes.¹ So I'm not sure if the Serious Eats experiment really applies to lentils.

Has anyone either confirmed or debunked the don't-add-salt thing specifically for lentils?

¹_{For example, soaking lentils in my experience just adds to the preparation time: it doesn't seem to make an appreciable difference in how long it takes to cook them, but it adds the time you had to take to soak them.}

Answer 1

I can only answer based on personal experience. I salt my lentils lightly at the beginning of cooking, and have never had an issue with them failing to soften or with the skins being tough. This goes for grey lentils, puy lentils, beluga lentils, and various types of dal.

That said, I haven't done a scientific test of cooking times; if it takes 10% longer for my dal to cook because I salted the water, I don't know that I'd notice.

I recommend against salting them heavily just because you might end up with lentils that are too salty.

Answer 2

If you look at lentil recipes, there is not agreement on whether to salt or not. In fact, this one begins with a salt brine...others say salt makes beans tough. I think the salt making beans (lentils included) tough is a myth has been debunked. This post refers to Harold McGee, who I would trust on the issue. It is acid that keeps beans from softening. The real issue with salt is that evaporation during cooking will increase your salt concentration. If you don't keep track of this, you can end up with overly salty beans. That, in and of itself, might be a good reason to wait, almost until completion, to salt your beans.

Answer 3

Old beans and lentils are difficult to get to cook properly. Salt is not the culprit.

Answer 4

Well I just learned the hard way. DO NOT ADD SALT AT THE BEGINNING! I didn't read the recipe all the way through and I am cooking lentils for the first time. I always add salt to regular beans with no issues. I have lentils cooking on the stove right now and couldn't understand, that after 25 minutes they were like I was eating small raw peas. Then I read the recipe through. I feel like an idiot. I checked again at 45 minutes and they are slightly (very slightly) better. I got nothing to lose, so I'm going for an hour. Lesson learned the hard way!