Limescale is a simple word for naturally occurring salts dissolved in water. When water boils, the salts break free of the water and stick to metal. That is how electric kettles get furred up.
While chefs are very aware of the mechanical problems that can come from limescale in the pipework of equipment such as combi-ovens and dishwashers, beverage making is not normally something a chef is involved with. More likely it is the front-of-house staff who do the tea and coffee making, and they may be unaware of how water can affect both the performance of the beverage equipment and the taste of the drink.
The main water problems that concern tea and coffee machines are water hardness and the chemicals that are put into mains water to purify it. Water with lots of dissolved salts is referred to as hard water, while water with a low concentration of dissolved salts is referred to as soft. Lots of dissolved salts means lots of limescale problems.
The hardness affects tea- and coffee-making equipment and, to a lesser extent, the taste of the drink. The chemicals that water companies use in water purification mainly affect the taste of the drink. Limescale, while invisible most of the time, can sometimes be seen as a faint scum on the top of a cup of black coffee.
Where it becomes a problem in water boilers for tea and coffee machines is when the hard, chalky limescale builds up on the inside of the tiny-bore water pipes. The first problem is that the limescale forms a layer of insulation, so the machine needs more electricity to heat the water up. The second, and more serious, problem is that the pipes become so constricted by limescale build-up that the water can't flow properly. This results in poor coffee and poor performance. Even worse, it can cause serious and costly damage to a machine.
Mains water is filtered with chlorine to kill water-borne bugs. The effect is not as unpleasant as drinking the water in a swimming pool, which is heavily chlorinated, but chlorine certainly doesn't blend with coffee in the way frothy milk does.
The upshot of this is that any coffee machine or water boiler used for tea-making that is connected to the mains should have a water-treatment unit fitted to it. This can be a machine that filters out just the miscellaneous tiny particles of debris, the salts, the chlorine or absolutely everything.
There are many different water-treatment systems for beverage machines, and the choice is dictated by the contaminants in the mains water. It is possible to buy a system that renders the water virtually sterile, but one of the perverse laws of water treatment is that taking every trace element out of the water can lead to flavour failure in coffee. A little bit of salt in coffee - like a little bit of salt in boiled potatoes - enhances the flavour, and both products can taste bland with salt-free water.
Choosing the right water-treatment system is not as simple as merely reading all the brochures. It takes analysis of the water and the volume of water being used. Kit Free, a director at European Water Care, says reputable suppliers of water-treatment systems will offer a site water test as part of an installation survey. This, says Free, will also determine how often filters need changing.
Neglecting to change water filters is one of the biggest self-inflicted problems that can happen to beverage machines. Filters may last as long as a year or need changing in as little as three months, depending on the volume and hardness of water passing through.
Coffee machine manufacturers are so concerned about the fitting of water filters that some insist on them being in place before installing a machine. Brasilia is one of the militant companies, insisting that a calcium-treatment unit be fitted to all its coffee machines to ensure drink quality and keep down maintenance and repair bills. First Choice Coffee, importer of the Swiss-built Black & White coffee machines, also insists on water treatment with every machine fitted, mostly choosing Everpure water filters - while for the Reneka traditional French espresso machines and the automated Swiss-made Franke bean-to-cup machines imported by Tudor Tea & Coffee, the first choice is Brita water filters.
Water treatment suppliers
European WaterCare Systems 01279 780250
Everpure UK 01280 822366
Brita 01932 898800
- CESA, the Catering Equipment Suppliers Association, has produced a guide to water-treatment systems for beverage machines. A free copy is available by calling 020 7233 7724
Don't forget the milk
While taking care over the purity of water going through a coffee machine will help maintain drink quality, both quality and food safety standards in coffee will be affected if milk holding and frothing systems are not properly maintained. Milk is a very bug-friendly environment, and the steam wand used to froth milk for drinks such as cappuccinos and lattes needs meticulous care.
Bill Davy, sales manager at the Coffee Machine Company, which distributes the Italian-built Rancilio brand, says not only is the steam nozzle a breeding ground for bacteria, but if it is not kept clean a milk build-up will eventually block it completely.
Davy says it is important to wipe the steam nozzle after each use to remove milk - but much more important is to wipe it with a clean cloth, not the one that has been used throughout the shift.
While table-top machines using soluble ingredients are usually for coffee drinks, Bravilor has added a machine to its Bolero range which is for hot chocolate. The Bolero 11 series has models for connection to mains water or for stand-alone manual fill. Output is up to 240 cups of hot chocolate an hour, and dispense options are for single cups or into flasks. The mixing chamber delivers the chocolate with a creamy top layer, and other features include a descale warning system and digital counter.
AVAIABLE FROM: Bravilor 01628 776060
While soluble-coffee machines are normally seen as being for low-volume needs, Balmoral has added a machine designed for bulk coffee service to its range. The CaféCino XL is aimed at hotel banqueting, conferencing facilities and sporting arenas, where demand is sudden and intense. Output is 10 seconds for 40 servings of black coffee. In addition to black coffee, the CaféCino XL can dispense individual cups of cappuccino, latte, espresso and hot chocolate. All drinks are dispensed by push-button controls. Balmoral plans to offer the CaféCino XL free on loan with an ingredient contract, for rental or for outright purchase.
AVAILABLE FROM: Balmoral 01536 536536
What systems are available?
- Water softeners - these add a slight amount of salt to the water, which has the effect of greatly reducing the amount of dissolved limescale that will be released when the water is heated. Suitable where the water is not directly for consumption, such as in dishwashing or laundry, but not recommended for connection to a beverage machine because of the slight increase in saltiness. Sometimes referred to as ion-exchange systems.
- Carbon filters - these will remove chlorine and discoloration, but not hardness. So if the business is located in a soft water area, but there is a wish to make the water taste better for water boilers and coffee machines, carbon filters are an option.
- De-alkalising units - sometimes called calcium treatment units, because they remove the hardness as the water passes through. These work on the ion-exchange system and are suitable for beverage machines and vending machines that serve hot drinks.
- Demineralisation - this removes almost all the dissolved minerals and hardness in the water and is an option where the water is hard. This is where some flavour loss can creep into coffee machines. The most common way of demineralising water is through reverse osmosis.
- Reverse osmosis - while this sounds like high science, it is in principle a fairly simple water-treatment system. The water is forced under pressure through a very thin filtering membrane, like a sieve, which removes not just the harmful limescale but many other trace elements, giving water that is very pure. But total removal of trace elements may change the flavour of beverages. For use in delivering very pure water or where the water is exceptionally hard. Unless absolutely necessary, not normally used in conjunction with beverage machines.
Fracino, the UK manufacturer of espresso and cappuccino machines, has launched Attimo, a self-service instant-coffee machine that produces up to 200 coffees an hour.
The machine features three canisters for soluble ingredients with 20 drink options from 10 touch-pads. Francino says the machine is intended for high-volume outlets such as fast-food or roadside restaurants or leisure stadia.
AVAILABLE FROM: Fracino 0121-328 5757
Coffee Machine Co
The Coffee Machine Company, distributors of the Rancilio range of Italian espresso machines, has a new model, the Classe 10, which features an automatic milk frother.
The single most difficult function in the making of speciality coffees is, according to the Coffee Machine Company, the manual frothing of milk for long drinks such as cappuccino and latte. The automatic frother is an option developed by Rancilio that deskills the art of milk frothing. All service staff need do is to place the steam wand in the milk and the machine automatically steams the milk to the preset temperature, followed by a self-clean cycle.
Available in two-, three- or four-group dispense head models, the machine is an all-metal construction with microprocessor controls which display warnings on the machine's central LED panel.
PRICE: two-group model £4,255
AVAILABLE FROM: The Coffee Machine Company 020 7237 6862
The growing demand for bean-to-cup machines that offer quality coffee in a compact footprint has seen Viva Espresso begin importing the German-built Bremer 24 machine. Footprint width is just 24cm, but output is up to 120 coffees an hour. The machine is fully automatic, working from a coffee bean hopper holding 2kg of beans. Options include a hot water outlet for tea production and a manual steam arm.
AVAILABLE FROM: Viva Espresso 01707 375444
Gaggia has introduced a compact espresso machine aimed at small restaurants, pubs and coffee shops that don't have a high turnover in daily coffee sales but wish to offer a true espresso coffee. The TS can use either loose ground coffee or compacted pods. The machine does not require plumbing in, as it relies on a manual-fill water tank of 2.5 litres. Despite being a compact, light-duty machine, the Gaggia TS still delivers a bar pressure of 13, capable of producing a good crema.
AVAILABLE FROM: Gaggia 01422 330295
Kenco has launched a range of hot drink vending machines that feature the Kenco name on the fascia panels to tempt customers with a familiar high-street coffee brand. The vending machine manufacturers in the new range are Westomatic, Crane and N&W. Kenco branded paper cups are stocked in the vending machines.
PRICES: from £5,660
AVAILABLE FROM: Kenco 0870 241 4820
Published by: The Caterer