- Posts: 1077
- Thank you received: 13
Recently on the web I encountered some sources that say
that Cleancaf which is a descaler and cleaner is not safe to use on an espresso machine.
Generally, a flush through descaler uses about .5 to .75 fluid ounces (1 to 1.5 tablespoons, or 8 to 12 grams) of citric or tartaric (grape) acid powder dissolved in 1 liter of water. This is a 2.25% to 3.5% solution, equivalent to 33% to 50% dilute lemon juice. Cleancaf and other coffee manufacturers' descalers use this formula. Theoretically, these amounts will dissolve about 12 to 18 grams of scale per liter, but that would require leaving the solution in for several days; in practice, it is used for an hour or two to dissolve up to 5 grams of scale.
The formula is mild enough to be harmless to espresso machine components, but it will come out of brass or copper machines with a slight greenish tinge. This comes from milligram levels of dissolved copper and is no cause for alarm.
Five pound bags of citric or tartaric acid cost about $10 at home brewers' or soapmakers' supply stores. This is roughly a 20 year supply
Descaling Intervals Know the hardness of the water you're using, and how much you use the machine. Descale when accumulations are between 2.5 and 5 grams. More often is a waste of time, less often may result in scale build up. Check out section 1.7 for instructions on determining your set up's scaling rate.
Single Boiler Machines
For single boiler machines, preventive descaling is no problem, just follow the instructions given by the manufacturer. In general, this involves filling the boiler, letting the solution work for about ten minutes, and replacing it by running it out of the steam wand under pump pressure. This procedure is repeated three to five times, until about a liter of descaler is used up. Then the machine is flushed with water until any taste is gone.
Manufacturer's recommendations differ on whether the brewhead should be flushed or not. This is not surprising. The water's temperature drops and LI rises as it moves from the boiler to the head, so scale won't form there. In scaled machines however, fragments can move from the boiler into the head, fouling the gicleur valve. My guess is that with regular descaling, flushing the head is unnecessary but harmless.