Descaling Coffee Machines

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De-Scaling Coffee Machines
Information about Limescale and calcium carbonate
Hard water contains high levels of calcium carbonate. It enters the water from
rainwater which has been in contact with chalk or limestone. It is not treated
before it enters the house for use. The water has high levels of calcium and
magnesium ions.
Hard water is a diluted solution of calcium carbonate (CaCO3). When the water
is heated up/boiled or when the water pressure changes, the calcium
carbonate separates and it reverts into chalk again. It can only happen if the
temperature goes above 61 degrees. This is now referred to as lime scale. Lime
scale is basically hard deposits of chalk.
Parts of the coffee machine and maintenance
Lime scale can affect the working of the coffee machine. It can also alter the
taste of coffee. Maintenance needs to take place every 3-6 months depending
of the hardness of the water. Filtered or softer water will still contain some
calcium carbonate and will need descaling less often.
The boiler in the coffee machine will not work if the lime scale is build up too
much. This will cause the main part of the coffee machine not to work. The
temperature will be affected by damage inside the machine. It will decrease as
the build up of limescale gets worse. Permanent damage can happen if it is left
untreated. The water within the coffee machine should be changed often to
stop the limestone being able to bind to the outside of the kettle or coffee
Useful Facts:
Stainless steel is harder to clean because it can corrode in a different
way to other metals.
The de-scalers must be able to dissolve or soften limescale
Carbonate + Acid = Water + Carbon Dioxide + Salt
All of the de-scaling chemicals are quite weak

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Ethanoic acid
It has a Ph. of 2.8
It is an acid because of the Ph of 2.8 but it is not as acidic as the other
two acids
When oxygen is formed with ethanol, it produces ethanoic acid.
It is in vinegar as it has a slight sour taste.…read more

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Citric Acid
It has a Ph. of 2.1
It is high on the Ph scale of acids
Lemon juice can work as well as citric acid
Some coffee machines can only use citric acid
Advantages Disadvantages
It is cheap It needs to be diluted to be
It is a weak organic chemical used
It tastes better after use than Can take longer for the
vinegar limescale to dissolve.…read more

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Sulfamic Acid
It has a Ph. of 2.…read more

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