Ask two shops with the same stock why their ramen tastes different and the answer is a spoonful of something dark in the bottom of the bowl. Tare is the concentrated seasoning of ramen, the salt, soy or miso base that seasons the soup at the last second, and it is the component where a shop's personality lives. The stock is the body. The tare is the opinion.
Why it lives in the bowl, not the pot
The separation is the genius of the format. If you seasoned the whole stock pot, every bowl would taste the same and the soup could not be adjusted table by table. By keeping a neutral stock and a concentrated tare, one day of boiling serves every style on the menu, and the cook calibrates each bowl by the ladle: tare first, aroma oil if the house uses one, then the hot stock stirred over it. When a bowl arrives over-seasoned or thin, the culprit is this ratio, and the good shops drill it until it is muscle memory.
The three classical tares
Shio tare is salt dissolved with dashi and often a touch of sake and mirin, the lightest and oldest, and the one with nowhere to hide, its bowls are judged on the stock alone. Shoyu tare is soy sauce sharpened with dashi, mirin and sometimes a spoon of chicken or shellfish essence, the Tokyo standard since the first dedicated shops. Miso tare is blended fermented paste, sometimes two or three ages of miso together, loosened with dashi into a spoonable sauce, the Sapporo school, built to stand up to rich soup and cold weather.
The fourth element, the aroma oil
Most bowls carry one more measured spoon before the stock: a fragrant oil that floats on the surface and carries scent to the nose with every lift of noodles. Chicken fat is the common one, mayu, the blackened garlic oil of the Kyushu tradition, is the dramatic one, bitter, sweet and glossy, and chilli oil in its various strengths runs from accent to statement. The oil layer also holds heat, which is why a proper bowl of ramen steams longer than the soup alone should allow.
Ours, on the pork bone base
The house soup is Kyushu pork bone, cooked to the white emulsion that article on this site explains, and the tare decides what it becomes. The miso tare carries the Miso Ramen, the shoyu-leaning seasonings carry the Kyushu and Buttercorn bowls, and the chilli paste, the one the founding suppliers complained burned their hands, is a tare of its own, measured out by the count you give the staff, from a gentle one to the sixteen at the top of the ladder. Same stock, same day of boiling, sixteen different opinions. That is what tare is for.
Blending one at home
The home cook can hold the concept in one paragraph. Start with the best liquid you have, dashi, chicken stock, even the remains of a Sunday roast, and season a small cup of it hard, soy, a touch of mirin, a pinch of salt, tasting until a spoonful of it alone is almost too much. That cup is the tare. Pour it in the bowl, ladle hot stock over it, taste, and adjust with more of one or the other, the same calibration the shop does, in miniature. You will discover the ratio by the second bowl, and the discovery is the lesson, a seasoned bowl is seasoned at the end, by choice, and never by accident. The full workflow, broth to bowl, is in the guide to making ramen at home.