Water sommellerie professionalized abroad over the past two decades and is now beginning to consolidate in Brazil. Where there is a mature wine list, a water list begins to appear — and with it the need for a technical criterion to support each choice. Among the available parameters, one proves more useful than the rest for anyone who builds and defends a list: TDS.

This text assumes the concept is already familiar. For the reader who needs the introductory definition, it lives in the foundational piece on the subject. Here the interest is different: how the professional reads this number, what it allows them to decide, and where it enters the service.

Why TDS is the key criterion for the water sommelier

A water can be described by several numbers. pH indicates acidity or alkalinity. Hardness measures calcium and magnesium. Conductivity estimates the presence of dissolved ions. Each says something. None summarizes as well as TDS.

Total dissolved solids gather, in a single value in milligrams per litre, all the mineral matter the water carries. It is the sum the palate perceives as weight, texture and presence. Two waters of the same pH can behave in opposite ways at the table if their TDS differs. The reverse rarely happens: waters of similar TDS tend to occupy a similar sensory register.

There are three practical reasons to anchor the decision in TDS. It is internationally comparable — the method is the same in any serious laboratory, and the number means the same in São Paulo, Milan or Tokyo. It is always on the report, requiring no indirect interpretation. And it corresponds to the table experience: the TDS range anticipates, with good fidelity, how the water will behave alongside a dish and a glass.

The international scale applied to the list

The Fine Water Society organizes fine waters into mineralization bands, and this scale is the most widely used reference for classifying water by TDS. It serves as the backbone of any list that aims for coherence. Five bands cover the spectrum of what is served at the table.

Super Low — below 50 mg/L

This is the band that most interests contemporary fine dining. It gathers rare origins — glaciers, deep aquifers, atmospheric harvesting. AWA, harvested from the humidity of the Amazon Rainforest, measures TDS on the order of 6 mg/L, close to the lower detectable limit. These are waters of silky texture and minimal presence, almost without a mineral signature of their own. On the list, they serve the most delicate dishes, low-intervention white wines and subtle spirits, where any excess minerality would compete with what is on the plate or in the glass.

Low — 50 to 250 mg/L

This holds a large share of the premium waters in widest international circulation. It is the band of broadest application: it accompanies most menus without imposing character, and works as a neutral table water when the list offers a single still option.

Medium — 250 to 800 mg/L

Here minerality begins to have a voice. These are waters that support denser dishes — reductions, poultry, pastas with full-bodied sauces — and dialogue well with medium-aged cheeses, where some mineral presence adds rather than detracts.

High — 800 to 1,500 mg/L

Declared minerality. It calls for dishes of equivalent weight: long-cooked meats, blue cheeses, intense preparations. Alongside a full-bodied red, high-mineral water keeps pace without disappearing.

Very High — above 1,500 mg/L

A niche category. Its function here is less gastronomic and more physiological — strongly mineralized waters, often sought for calcium or magnesium intake. They rarely form part of a restaurant list as an accompanying water.

TDS and pairing: the fundamental rule

There is a rule that organizes almost every minerality-pairing decision: the water must not compete. Its TDS should be comparable to or lower than the whole formed by the dish and the glass. Water more mineral than the dish gets ahead of the palate and tires it; water lighter than the whole fades, but never harms. When in doubt, the lighter choice is always the safer one.

Delicate dishes

Raw fish, ceviche, oysters, minimally prepared vegetables. The Super Low band is practically mandatory. Any mineral presence above that masks the delicacy of what is served.

Medium dishes

Grilled fish, poultry, pastas with light sauces. Low, and at most Medium. The water may have some texture without taking the lead.

Dense dishes

Long-cooked meats, aged cheeses, reduced dishes. Medium or High. The minerality matches the weight of the preparation and cleanses the palate between bites.

Desserts

Here the water makes a sensory restart, preparing the palate for the sweet. Return to Super Low or Low — a lightness that reopens rather than saturates.

TDS and wine: two fluids at the table

Water and wine share the table and the palate, and the water's minerality affects the perception of the wine as much as that of the dish. The logic repeats that of pairing with the dish, now applied to the second fluid. Light white wine, low-dosage sparkling and elegant reds of little extraction call for Super Low water: any minerality above that hardens the perception of the wine and flattens its acidity. Full-bodied reds, with present tannins, tolerate and sometimes call for a Medium-band water, which keeps pace with the body without fading. The combination to avoid is constant: an elegant wine with high-mineral water. Mineral water competing with the wine masks the main drink, and the wine loses definition.

How to read a report

On the report, TDS appears as one line among others — pH, conductivity, alkalinity, and the individual mineralization of each element. It is worth checking the coherence between the stated TDS and the sum of the minerals listed: serious reports add up. It is advisable to note the date and the laboratory — mineralization varies with the operation and the season, and a number without a recent report says little. Before adding a water to the list, the professional checks whether the number they will communicate has current documentary support. It is this support that separates a technical argument from an impression.

Professional protocol

Knowing the TDS of each water on the list is a technical obligation. Communicating it is a service decision. The water sommelier states the number when it adds something — in a suggested pairing, in presenting a bottle whose origin justifies the conversation, in answering a guest who asks. Beyond that, discretion is the register. Knowledge supports the choice; it need not be displayed to operate. On a written list, TDS may appear soberly, beside the origin, as data available to those who look for it — not as a headline argument.

The Super Low category and the present moment

Of all the bands, Super Low is the one growing most in demand in fine dining. The reason is sensory and cultural at once: contemporary kitchens work increasingly with low-intervention preparations that call for a water that does not interfere, and the reference diner has come to value origin and rarity in water as much as in wine. Origins capable of delivering ultra-low mineralization are few — glaciers, deep aquifers and, more recently, atmospheric harvesting. Atmospheric water from the Amazon, expressed today by AWA, is the Brazilian version of this band — a singular origin, documented ultra-low mineralization, available through a selective circuit.

Final considerations

TDS is not the only criterion for a water list. Origin, the materiality of the glass, coherence with the house and availability all matter. But it is the most solid technical starting point for anyone who builds and defends a selection — the number that organizes the scale, guides pairing and supports the conversation with the guest when it happens. It is the knowledge that separates the professional who built the list with criterion from the one who works with a pre-existing list without technical ownership.