Soda water

This redirect is about the beverage "soda water". For Carbonated water, see Soda water (disambiguation).

A Soviet era soda water vending machine in Bishkek.

Soda water, also known as seltzer in the US and Canada, is water which is carbonated and thus made effervescent by the addition of carbon dioxide gas under pressure. Soda water is sometimes used to dilute strong alcoholic drinks, e.g. cocktails such as a whisky and soda, or Campari and soda. It can also be drunk on its own. Soda water gets its name from the sodium salts it contains, said 'salty' compounds adding a distinct and pleasurable quality to many beverages of the alcoholic, and non-alcoholic type.

Soda water was introduced in the latter part of the 19th century, reaching Calcutta in 1812, and siphons in the home were a symbol of middle-class affluence by the early part of the 20th century.

The soda siphon, or syphon - a glass or metal pressure vessel, with a release valve and spout for dispensing pressurised soda water, was a common sight in early-to mid 20th century homes and in bars.

In Europe "soda" means carbonated water dispensed from a soda siphon. In the US the term has come to mean all carbonated soft drinks such as colas. Soda water may be differentiated from plain 'carbonated water' by the common addition of various sodium or potassium compounds as flavourings and acidity regulators, and the term 'carbonated water' is still not as in such widespread use today as 'soda water'.

Chemistry

Carbon dioxide and water form carbonic acid. Alkaline salts such as sodium bicarbonate are added to soda water to reduce the acidity. The sodium or other metallic salts used in soda water may help to neutralise a little of the acidic flavour in some drinks, such cocktails made with orange juice. 'Club soda' in the US may contain other compounds and flavourings and be therefore more akin to a 'soft drink or 'soda' pop, than soda water.

History

Decline and fall

The popularity of soda water has declined since the late 1980s as drinking habits and fashions change and new bottled or canned beverages arrive, but soda-siphons are still bought by the more traditional bar trade and available at the bar in many upmarket establishments. In the UK there are now only two wholesalers of soda-water in traditional glass siphons, and an estimated market of around 120,000 siphons per year (2009). Worldwide, preferences are for beverages to be distributed in recycleable plastic containers which may, or may not, be recycled. The heavy glass needed for soda siphons is seen as environmentally unsustainable, despite glass soda siphons being easily repaired and refilled by manufacturers.

The renaissance of soda water

Home soda siphons, and soda water are enjoying a renaissance in the 21st Century as retro items become fashionable. Contemporary soda siphons are commonly made of aluminium, although glass and stainless steel siphons are available. The valve-heads of today are made of plastic, with metal valves, and replaceable o-ring seals. Older siphons are in demand on on-line auction sites. Carbonated water, without the acidity regulating addition of soda, is currently seen as fashionable although home production (see below) is mainly eschewed in favour of commercial products.

Social History

Soda water changed the way people drank. Instead of drinking spirits neat, soda water, and later, carbonated soft drinks such as Dry Ginger, helped dilute alcohol, mitigating its harsh effects, and made having a drink more socially acceptable. Popping into a chum's house for hospitality from a "dash and a splash" - a whiskey and soda before going out to a social event was part of everyday activity in Britain as late as 1965. Whiskey and sodas can be seen in many British TV series and films from the 1960s and earlier and the soda siphon is ubiquitous in many movies made before 1970. Social drinking would change with the counter-culture anti-establishment movement of the 1970s, and the decline of soda water would begin from that point. Soda water's 'last hurrah' in Britain may have been the popular 1970's product, 'Soda Stream' A commercially available home bottling kit, which enabled purchasers to combine fruit syrups, and water, to create sparkling beverages. The famous advertising tag-line 'Get Bizzy With The Fizzy' spawned a series of simialr expressions, such as 'Get Buzzy With the Fuzzy'. Families who could not afford 'Sodastream' would often make do instead with a syphon, a packet of sparklets, and a bottle of orange squash.

Soda water and health

There are some, as yet undemonstrated, claims of dental decay due to carbonated water, but there is currently no citable evidence that a 'dash and a splash' (whisky and soda) causes anything other than temporary intoxication.

Manufacture

A modern bar soda "gun."

Commercial soda water in siphons is made by chilling filtered plain water to 8 degrees Celsius, adding a sodium or potassium based alkaline compound such as sodium bicarbonate to reduce acidity, and then pressurising the water with carbon dioxide, known as Carbonation. The gas dissolves in the water, and a top-off fill of carbon dioxide is added to finally pressurise the siphon to approximately 120 psi (pounds per square inch), some 30 or 40 psi higher than is present in fermenting champagne bottles.

In most modern restaurants and drinking establishments soda water is often manufactured on-site using devices known as carbonators. Carbonators utilise filtered water and pressurise it to approximately 100 psi using mechanical pumps. The pressurized water is stored in stainless steel vessels and CO₂ is injected into the water producing carbonated water. The water is then pumped to either a pre- (syrup is mixed with soda water before dispensing) or post-mix (syrup is mixed with soda water as it is being dispensed) soda fountain or dispenser.

Israel claims to be the worlds leading producer of Soda water, which may explain the traditional phrase 'it would be easier to carbonate the dead sea!'

Soda siphons

An antique soda siphon circa 1922.

The gas pressure inside a siphon pressure vessel drives soda water up through a tube inside the siphon when a self-evident valve actuation lever at the top is depressed. Careful regulation of the valve lever is needed by the operator of the siphon to prevent pressurised soda water being released into the drink, which then splashes forcibly upwards, often soaking the operator, or at least causing a social gaff.

Soda siphons are therefore best kept away from children, intoxicated people, or the infirm, unless streams of pressurised water are to be intentionally used for mirthful purposes.

Uninhibited discharge of soda siphons for non-beverage or humorous occasions in bars and pubs has led to the removal of soda water from most establishments in Britain. Actuation of a soda siphon other than into a drinking vessel or for the purposes of quenching thirst, or perhaps extinguishment of extemporaneous conflagrations, may constitute breach of local or international legislation, with consequent risk of penalties or imprisonment.

Use

Soda water is a diluent; It works well in short drinks made with whiskey or brandy, and in long drinks such as those made with vermouth. Soda water may be used to dilute drinks based on cordials, orange squash, and is particularly refreshing taken with the bianco vermouth over ice, especially in hot weather. Soda water is a necessary compound in many cocktails, where it is used to top-off the drink and provide a degree of 'fizz'. Adding soda to 'short' drinks such as spirits dilutes them and makes them 'long'.

The addition of soda water to dilute spirits was especially popular in hot climates and seen as a somewhat "British" habit. Adding soda water to quality Scotch whiskey has been deprecated by whiskey lovers, but was a popular lunchtime drink or early evening pre-dinner or pre-theatre drink until the late part of the 20th century.

Pre-filled glass soda-siphons were sold at many liquor stores, a deposit was charged on the siphon, to encourage the return of the relatively expensive siphon for re-filling. In 1965 the deposit on a single soda-syphon in England was 7/6d (seven shillings and six pence.)

Soda water can be made at home, by use of a readily available 1 L (1.1 US qt) rechargeable soda-siphon, and disposable one-shot screw-in carbon dioxide cartridges. A simple recipe is to chill filtered tap water in the fridge, add one quarter to one half a level teaspoon of sodium bicarbonate (baking soda) to the rechargeable soda-siphon, pour in the chilled water and add the carbon dioxide. If you have a pH testing kit, you can use it to alter the amount of sodium bicarbonate per litre of carbonised water to neutralise the acidity. A bunsen burner may be used to bring carbonic acid solutions up to a notional average temperature for measurement, but eye protection and safety precautions should be worn in the presence of heat, pressurized inflammable gas, acid or alkali solutions. See previous notes on the efficacy of soda water in the extinguishment of unintended fires.

The siphon should be kept in the refrigerator to preserve carbonation of the contents, and brought out for use, but many rechargeable soda-siphons are handsome objects in their own right, and are kept out for viewing on the drinks tray in many homes.

Soda water made in this way tends not to be as 'gassy' as commercial soda water although chilling of the water before carbonation helps.

See also

• Carbonated water
• effervescence