Recap
- Water has the potential to cause scale and/or corrosion of brewing equipment.
- Cafe water needs to be carefully monitored to ensure it is balanced between too soft and too hard.
- It is possible to use a Langelier Saturation Index calculator to ascertain if you water is balanced.
- To maintain good water, it is necessary to perform regular tests for general hardness (GH), and carbonate hardness (KH), potential of Hydrogen (pH) and total dissolved solids TDS.
- Limescale, is not as thermally conductive as copper or aluminium; scale buildup has the effect of encasing heating elements in an insulating layer.
- Some authorities require pressurised equipment to undergo regular pressure testing.
- Crack and crazing will occur in plastic polymers like acrylic if they encounter physical stress like being dropped.
- Mechanical brewers need to be accurately levelled to facilitate even extractions.
Glossary
Calcium bicarbonate the bonding of dissolved calcium and dissolved CO2 in water.
Calcium carbonate the mineral compound that precipitates from heated water that contains dissolved calcium and carbon dioxide.
Corrosion the gradual damage to the surfaces of brewing equipment (usually metal) when in contact with water, air and chemicals.
Crazing The development of small fissures in a polymer along the regions where two substances are fused through polymerisation. This is usually caused by tensile stress.
Limescale The term for calcium carbonate buildup on the surfaces of coffee equipment.
Isolation valve A form of tap, which allows the flow of water to be shut off as the valve is adjusted.
Plumbed-in Where brewing equipment is attached to pressurised water mains.
Polymerisation A chemical process used in manufacturing plastics where small molecules are fused to create large molecules in long chains.