A cook I know puts a pinch of sugar in almost everything savoury he makes. When I asked why, he said it was to balance, which I found unsatisfying, so I started paying attention to what it was actually doing.
The answer is more interesting than "balance" and it has made me both use it more deliberately and worry about it less.
What sugar does that is not sweetness
At small quantities — a quarter teaspoon in a dish for four — sugar is below the threshold at which most people perceive it as sweet.
What it does instead is suppress the perception of other things. Sourness reads as less sharp. Bitterness recedes. Salt tastes rounder.
This is why it appears so often with tomatoes, which are acidic and sometimes bitter depending on the variety and the season. A pinch of sugar does not make the sauce sweet; it makes the acid less aggressive.
It also helps with browning, because sugar caramelises at lower temperatures than the sugars naturally present, which is why a touch of it in a marinade produces better colour.
Where I now use it deliberately
Anything tomato-heavy, particularly with tinned tomatoes, which are more acidic than fresh ones and vary a lot by brand.
Anything with a lot of tamarind or lime, where the sourness is the point and can tip into harshness.
Bitter vegetables. A very small amount alongside something like bitter gourd changes it from punishing to interesting.
And anywhere I have over-salted, where a pinch of sugar genuinely does make the saltiness read as less extreme. This is a rescue rather than a technique and it works.
Where it is doing something else entirely
Worth separating out, because this is where the health conversation belongs.
The pinch in a home-cooked sauce is negligible. A quarter teaspoon across four portions is about a gram of sugar each.
Commercial savoury products are a different matter. Sauces, dressings, ready meals and bread frequently contain substantial amounts, and there the purpose is not seasoning — it is palatability and shelf appeal, at quantities that add up across a day.
Reading labels on savoury products was more surprising to me than reading them on obviously sweet ones, which is presumably the point.
The traditional versions
Something I noticed once I started looking. A lot of traditional cooking uses sugar in savoury contexts and does not call it that.
Jaggery in dals and vegetable preparations across large parts of India, in quantities that are not trivial. Tamarind and jaggery together as a standard pairing. Sweet elements in pickle and chutney.
That combination — sour, sweet, salty, hot — appears independently in many cuisines, which suggests it is doing something real rather than being a regional quirk.
And it means the modern instinct to remove all sugar from savoury food is removing something that was there deliberately.
How much is too much
The practical test is whether you can taste it as sweetness. If you can, in something that is not supposed to be sweet, it is too much.
The threshold is lower than people expect. In a dish for four, a quarter teaspoon is usually right and a full teaspoon is usually detectable.
It also depends on what else is present. A dish with a lot of acid can carry more sugar before it reads as sweet, which is exactly why the two go together.
What I concluded
That the pinch of sugar in home cooking is a seasoning decision and not a nutritional one, and that treating it as a nutritional one leads people to make worse food for no measurable benefit.
And that the sugar worth thinking about is in the packaged savoury things, where the quantities are an order of magnitude larger and the purpose is commercial rather than culinary.
I use it more freely now, in smaller amounts, and more precisely, which is the opposite of what I expected when I started paying attention.
The alternatives, and whether they matter
People ask about jaggery, honey and the various unrefined sugars, generally on the assumption that they are better.
Nutritionally, at the quantities we are discussing, the difference is negligible. A quarter teaspoon of anything is a quarter teaspoon.
Where they do differ is flavour. Jaggery brings a molasses note that suits some dishes and intrudes in others. Honey has its own character and behaves differently under heat.
So the choice between them is a cooking decision rather than a health one, and choosing jaggery for health reasons while using the same amount is mostly a story you are telling yourself.
Where I would leave it out
Anything already sweet from its own ingredients. Dishes heavy with carrot, beetroot, coconut or ripe tomato frequently need no help, and adding sugar out of habit tips them over.
The test is always to taste first and add afterwards, which sounds obvious and is exactly what a habitual pinch prevents you from doing.