The embodiment of nature's perfection
Understanding Total Dissolved Solids:
Why mineral content matters in premium water
Total Dissolved Solids (TDS) in drinking water is not just a figure from a laboratory. TDS measures the concentration of dissolved minerals and other substances in water, providing insight into its mineral composition and character.
Those dissolved minerals can influence how water tastes and feels, from light, clean and balanced to heavy with a chalky finish. Understanding TDS helps explain why different waters have distinctly different sensory profiles, even when they all appear equally clear and refreshing. It is also one of the factors worth considering when water is served as part of a premium hospitality experience.
Key takeaways:
- TDS (Total Dissolved Solids) measures the concentration of dissolved minerals in water.
- TDS is commonly expressed in milligrams per litre (mg/L) or parts per million (ppm).
- Dissolved minerals can influence water’s taste, mouthfeel, weight and finish.
- Lower TDS waters are generally perceived as lighter, softer and more neutral, while higher TDS can contribute to a more pronounced mineral character.
- TDS does not determine water quality on its own. The individual minerals within the total TDS also influence taste and sensory character.
- Otakiri New Zealand Artesian Water has a naturally low TDS of 120 mg/L, contributing to its light, clean character and refined finish.
What is TDS in water?
Total Dissolved Solids (TDS) measures the concentration of dissolved minerals and other substances found in water.
TDS is one of the measurements used in water quality testing to understand a water’s composition and provides insight into its mineral characteristics. It reflects the combined concentration of dissolved organic and inorganic substances in the water.
Naturally occurring minerals, such as Calcium, Magnesium, Sodium and Potassium along with Bicarbonates, Chlorides and Sulphates are among the principal contributors to TDS.
Together, these dissolved substances form the mineral profile of the water. TDS measures their combined concentration rather than identifying each substance individually and is commonly expressed in milligrams per litre (mg/L) or parts per million (ppm).
How dissolved solids enter water
Water is a natural solvent, meaning it can dissolve and absorb molecules from a wide range of substances. As water moves through its environment, it comes into contact with soil, rock and other materials, gradually dissolving minerals and compounds along the way. The composition of water depends on what it encounters on that journey.
Dissolved solids can come from both natural and human sources.
Natural sources include rocks, soil, plants, lakes, rivers and underground water systems. Water that moves through mineral-rich rock, for example, can take on greater concentrations of naturally occurring minerals. The geology of a region therefore plays an important role in determining the mineral profile of its water.
Human activities, including agriculture, industrial processes, wastewater discharge and road de-icing, can also introduce dissolved substances into water.
Does TDS affect water taste, neutrality and finish?
The presence of dissolved solids can affect the taste and mouthfeel of water.
Total Dissolved Solids (TDS) can influence how water feels and tastes on the palate. Lower TDS waters are generally perceived as lighter, softer and more neutral in taste, while higher TDS can contribute to a more pronounced mineral character, weight and texture.
The relationship between TDS and taste has been recognised in World Health Organisation (WHO) guidance. Taste-panel research cited in the WHO Guidelines for Drinking-water Quality
found that palatability ratings generally declined as TDS increases.
https://cdn.who.int/media/docs/default-source/wash-documents/wash-chemicals/tds.pdf?sfvrsn=3e6d651e_4
Water with a TDS level below 300 mg/L was generally rated as excellent for palatability, while water between 300 and 600 mg/L was rated as good. Higher concentrations were progressively less preferred by the tasting panels.
Table 1: WHO taste-panel ratings by TDS levels
| TDS level | WHO taste-panel rating |
|---|---|
| Less than 300 mg/L | Excellent |
| 300–600 mg/L | Good |
| 600–900 mg/L | Fair |
| 900–1,200 mg/L | Poor |
| Above 1,200 mg/L | Unacceptable |
Source: https://cdn.who.int/media/docs/default-source/wash-documents/wash-chemicals/tds.pdf?sfvrsn=3e6d651e_4 WHO: Total dissolved solids in Drinking-water: Background document for development of WHO Guidelines for Drinking-water Quality
Interestingly, the relationship is not simply a case of lower being better. Water with extremely low levels of dissolved minerals can be perceived as flat or lacking character.
At the other end of the spectrum, higher levels of certain minerals can give water a more pronounced character. Calcium can contribute to a fuller mouthfeel, while higher levels of Sodium may introduce a subtle saline or savoury note. Depending on the mineral composition, water can also have a more noticeable mineral finish with hints of bitterness or dryness.
The individual minerals present also matter. TDS provides an indication of the overall concentration of dissolved substances, while the individual minerals present contribute to the water’s specific taste and flavour characteristics. Calcium, Magnesium, Bicarbonate and Reactive Silica, for example, can each contribute differently to the way water is perceived, meaning that two waters with a similar TDS level can still have quite different taste profiles.
A balanced mineral profile can give water a subtle presence on the palate, with a clean, refined finish.
Where Otakiri water sits on the TDS scale
Otakiri water has a TDS level of 120 mg/L, identified in our August 2025 water analysis report undertaken by Hill Labs. https://www.otakirisprings.co.nz/purified-by-nature
A TDS level of 120 mg/L places Otakiri New Zealand Artesian Water in the lower range of dissolved mineral content and well within the range that WHO taste-panel research has associated with excellent palatability. It is also well below the New Zealand Government’s drinking water quality parameter of less than 1,000 mg/L for TDS.
This relatively low TDS is a reflection of both the geology and natural protection of the aquifer from which Otakiri New Zealand Artesian Water is sourced. As water moves through underground formations in the aquifer, it naturally interacts with the surrounding volcanic rock, known as ignimbrite, dissolving and absorbing minerals along the way. Additionally, as the aquifer is naturally confined deep underground and held under immense artesian pressure, the water is protected from surface water and potential sources of environmental contamination.
The result is water with a naturally low TDS and the ideal naturally occurring minerals to give it presence on the palate, while maintaining a soft, clean, delicate profile and refined finish.
At 120 mg/L, Otakiri’s TDS is considerably lower than some internationally well-known waters, whose reported TDS levels can range from around 220 mg/L to more than 800 mg/L.
| Selected bottled waters | Reported TDS |
|---|---|
| Otakiri | 120 mg/L |
| Water 1 | 210 mg/L |
| Water 2 | 456 – 480 mg/L |
| Water 3 | 862 mg/L |
Why TDS matters when pairing water with food
Total Dissolved Solids (TDS) matters when pairing water with food because the concentration of dissolved minerals can influence water’s taste, mouthfeel, weight and finish, which can either complement or compete with the flavours of a dish.
The differences between higher and lower TDS levels can become particularly noticeable when water is served alongside food. A water with a higher TDS and more pronounced mineral make-up may have greater weight or a longer finish, potentially competing with delicate flavours on the plate. Water with a lower TDS and a softer, cleaner character can refresh the palate without distracting from the ingredients, allowing subtle flavours, acidity and texture to remain in focus.
However, TDS is just one of several factors that contribute to how water is perceived on the palate.
The individual minerals within the total TDS also influence specific taste characteristics, meaning that the aim is not to simply choose the water with the lowest TDS but to consider how its overall mineral character works alongside food and wine without competing with the menu.
For Otakiri, our naturally low TDS of 120 mg/L contributes to a light, clean character and refined finish, making it a considered choice for premium service.
How staff can explain low TDS simply
Guests and hospitality professionals who take an interest in the water being served may ask what makes it different, why it tastes so light, or why your venue has chosen to serve Otakiri. TDS provides a simple way to explain part of the story behind Otakiri’s distinctive pure character without needing to go into technical detail.
A simple way to explain it is:
“TDS tells us how much mineral content is naturally dissolved in the water. Otakiri New Zealand Artesian Water has a naturally low TDS of 120 mg/L which gives the water its soft, balanced taste and refined finish.”
FAQs
What is TDS in water?
TDS (Total Dissolved Solids) measures the combined concentration of dissolved minerals and other substances in water. It is commonly expressed in milligrams per litre (mg/L) or parts per million (ppm).
What does TDS level mean in drinking water?
A TDS level indicates the overall concentration of dissolved substances in water. It provides an indication of its mineral composition and can contribute to differences in taste, mouthfeel and finish.
What is a good TDS level for drinking water?
While there is no single TDS level that is considered ideal for every water, the World Health Organisation’s Drinking Water Guidelines refers to a taste panel in which found that water with a TDS level below 300 mg/L was generally rated as excellent for palatability, while water between 300 and 600 mg/L was rated as good. TDS describes the concentration of dissolved substances rather than water quality on its own. The individual minerals present and their balance also influence taste and sensory characteristics.
Does TDS affect the taste of water?
Yes. TDS can influence the taste and mouthfeel of water. Lower TDS waters are generally perceived as lighter and more neutral, while higher TDS can contribute to a more pronounced mineral character, weight and texture.
Is lower TDS better for drinking water?
Not necessarily. Very low TDS water can be perceived as flat or lacking character, while higher TDS can produce a more pronounced mineral profile. The ideal sensory experience depends on the composition and balance of the dissolved minerals.
What is Otakiri’s TDS level?
Otakiri has a TDS level of 120 mg/L as reported in our August 2025 water analysis report undertaken by HillLabs. This relatively low TDS contributes to Otakiri’s light, clean character and refined finish.
