BACKFLUSHING - A basic overview
picture shows a blind filter used for backflushing
Routine care of your Coffee Espresso machine will enable you to make quality espresso shots for many years. This guide will give you the basics for backflushing your coffee machine so your machine can produce great tasting espresso, and keep it in top condition.
Backflushing is recommended for coffee machines that have 3 way valves. Backflushing helps to eliminate stale tasting coffee as it cleans away the build up of old oils and ground coffee that may be sitting in the brew head.
Depending on your usage level, (number of drinks), backflushing the system is recommended at least weekly.
Using a blind filter (as shown above) or a plastic disc that sits at the bottom of the filter basket to block the holes - pull the handle (or if using a machine such as the Rancilio Silvia - switch the coffee brew switch on) and let the pump run for a few seconds. The pump noise should change to a higher pitched sound. When this happens return the handle or switch to the off position. Repeat this procedure 3-4 times. DO NOT leave the pump running with the blind filter in place for more than 10 seconds as it can damage the machine.
Remove the group handle, where you will notice used coffee grounds that have been stuck in the shower screen and gasket. Repeat the above procedure until the water runs clear.
Coffee cleaning products can also be used. Be careful with the cleaning powder or solution chosen for your machine. Some cleaners are not recommended for coffee machines with aluminium parts. Carefully read the label or instructions that come with the cleaner and use it for its intended purpose only. Precautions such as protective eyewear and gloves should be observed.
Using the cleaner in the blind filter, ensure you backflush the machine until the water coming out runs clear. Replace the blind filter with the filter basket (holes in bottom) and run a blank shot with just water. The first shot of coffee you put through the machine after backflushing should be discarded to eliminate the possibility of consuming cleaning soloution that may have been left behind.
Following the above schedule on a regular basis, plus cleaning other associated parts on your machine, such as the shower screen, group handle (sprout, filter baskets etc) will ensure your machine provides you with great tasting espresso for many years.
WARNING - DO NOT BACKFLUSH a machine that is not equipped with a solenoid valve. If unsure contact your supplier or machines manufacturer.