opposite of salty

saltless
figuratively - bland, tasteless;
fresh - but only to be used with water, not food

Thanks A Star. But how will you express it: you put salt in the soup but it is not enough to your taste?

There is no single word for this that I know. Just say - it needs a dash / pinch / bit more salt.

Thanks A Stars for your efforts to help me. But it is amazing that a powerful language like English does not have a single word to express a deficient in salt in dishes!

I forgot "unsalted" - I have seen it used in hospitals for foods served without salt, also on crackers that have no salt.
The dictionary showed "saltish" for "somewhat salty", and of course "briny" for water that has saltiness in between sea water and fresh water. I found nothing to describe "food that is not salted enough". Recipes say "salt to taste" - meaning to add salt until you like

how about using "flat"?
It tastes flat.

This isn't limited to the idea of salt.

Let's say I made lemon squares. I ask you how they taste. Since you're my friend, you will be honest, and say "I really can't taste the lemon strongly enough" or "It's not lemon-y enough." There is no single word for "doesn't taste strongly enough of lemon."

Let's say I made gingersnaps. They're perfect. You say "Oh, the spices are just ri

In Farsi we have the word bi-namak without-salt meaning "not salty". If we say something is bi-namak then we are saying there is salt, but not as much as we would like to have. So "unsalted" cannot be used in this sense. I guess if I had no choice to describe this thought with one word in english, I would say "saltless". "those crackers are not salty enough!" "those crackers are saltless!

salty, sour, bitter, sweet

None of these words really has a single-word opposite. We just deal with degrees.

[Some exceptions: bittersweet, unsalted]

In Arabic, there's a word to say "saltless, unsalted" to describe foods, which is "messos" "????". from the other hand, this has nothing to do with the example of lemon, because lemon doesn't give a taste of its own, it contains another taste " sour", however salt does have a taste wich it gives and spread for other associated foods.