Choose plain soda water when you want the mixer to add carbonation without sweetness: Fever-Tree lists carbonated spring water, bicarbonate of soda and sea salt for its Premium Soda Water. Choose a diet tonic when you want quinine bitterness and accept its sweeteners; Sainsbury's lists aspartame in Schweppes Slimline and acesulfame K and sucralose in its own Diet Indian Tonic. Do not assume a 'light' tonic has no added sugar: Fever-Tree's Refreshingly Light tonic ingredient lists include fructose.
The choice depends on whether your Italian-style drinks need neutral fizz or the bitter, sweetened flavour of tonic.
For a spritz, vermouth-and-soda or amaro highball where the drink's other ingredients provide the flavour, plain soda water adds carbonation without a sweetener ingredient in the Fever-Tree Premium Soda Water example.
If quinine bitterness and a sweetened tonic taste are part of the serve, compare diet tonics by their ingredient lists as well as their sugars per 100ml. The Schweppes and Sainsbury's examples use different sweeteners.
A light description is not a substitute for reading the ingredients. Fever-Tree's Refreshingly Light Indian and Rhubarb & Raspberry tonics list fructose, as does Fentimans Premium Indian Tonic.
Decide what the mixer should contribute to the drink, then check the ingredients and nutrition information for the particular bottle or can.
| Priority | What to check | Your needs |
|---|---|---|
| Added sugar | Read the ingredients for added sugars such as fructose; compare sugars per 100ml. A 'light' description alone does not establish that no sugar was added. | I want to avoid adding sugar through the mixer, not just choose one described as lower calorie. |
| Drink flavour | Choose between plain soda water and a quinine tonic. Consider whether tonic bitterness and sweetness suit the spritz or highball you plan to serve. | For vermouth-and-soda, I may want carbonation without tonic flavour; for a tonic-based drink, that bitterness is part of the choice. |
| Sweeteners | Read the named sweeteners and any relevant pack statements. Sainsbury's lists aspartame for Schweppes Slimline and acesulfame K and sucralose for its Diet Indian Tonic. | If guests have sweetener preferences, I want to know what is in the tonic before serving it. |
Fever-Tree lists fructose in its Refreshingly Light Indian and Rhubarb & Raspberry tonics. Fentimans Premium Indian Tonic also lists fructose and reports 4.4g sugars per 100ml.
If avoiding added sugar is the requirement, check the ingredient list rather than relying on the front-of-pack description. Choose plain soda water when tonic flavour is not needed.
The Schweppes Slimline and Sainsbury's Diet Indian Tonic examples use different sweeteners. Neither provides the same unsweetened flavour as plain soda water.
Check the sweetener names and relevant statements on the pack if they matter to your guests; offer soda water separately if you also need an unsweetened mixer.
The bottle or can is the practical reference for the formulation you are about to serve. Sainsbury's advises shoppers to read the physical label rather than rely solely on its online product information.
Check the current ingredients, sugars per 100ml and any dietary statements on the pack at purchase.
These examples show why the particular product and its ingredients matter more than the brand name alone.
Premium Soda Water offers a plain mixer route; the Refreshingly Light tonics are different products.
Slimline Tonic Water is a quinine-tonic example rather than a plain soda-water alternative.
Premium Indian Tonic Water is a botanical, quinine-led tonic for drinks where its flavour is wanted.
Britvic announced a zero-sugar Indian Tonic Water in a 330ml can in September 2023.
Tesco lists its own-label Soda Water in a sugar-free-filtered grocery category.
Diet Indian Tonic Water is an own-label option for a quinine-tonic serve.
This pack is a tonic-water option for drinks where you want tonic flavour rather than the neutral carbonation of soda water. Check its current label against your added-sugar and sweetener requirements.
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For an Italian-night drink where tonic flavour is wanted instead of plain soda water. This is a 12 × 150ml pack; check the pack's ingredients, sugars per 100ml and sweetener statements before buying.
No. For Great Britain, the Advertising Standards Authority's September 2025 guidance says a no-added-sugars claim excludes added mono- or disaccharides and foods added for their sweetening properties. To decide whether a mixer suits you, check both its ingredients and its sugars per 100ml rather than treating the descriptions as interchangeable.
The ingredient lists for Fever-Tree Refreshingly Light Indian Tonic and Refreshingly Light Rhubarb & Raspberry Tonic include fructose. Do not choose those products for a strict no-added-sugar requirement on the strength of the 'light' description.
Plain soda water supplies carbonation without the sweetened tonic flavour. Fever-Tree lists carbonated spring water, bicarbonate of soda and sea salt for its Premium Soda Water; check the other ingredients in your drink separately if their sugar content matters.
Not necessarily. Sainsbury's lists aspartame for its Schweppes Slimline Tonic Water 1L listing, while its own Diet Indian Tonic Water lists acesulfame K and sucralose. Read the current pack when choosing a particular size or format.
Yes. Check the bottle or can for current ingredients, sugars per 100ml and any relevant dietary statements. Sainsbury's specifically advises reading the physical label rather than relying solely on its online product information.