Backflushing Your Espresso Machine
Backflushing is an important piece of maintenance that should be done regularly on many Espresso Machines. The process of backflushing forces water and cleaner back through the systems over pressure valve to remove any build up and keep the valve in good working order. Furthermore, backflushing helps to remove old coffee oils that can build up causing your machine to clog and alter the taste of your espressos.
How Often Should I Backflush?
Backflushing should be factored into a regular cleaning regime for your espresso machine, typically in a home setting a backflush without any cleaning chemical should be done once a week but can be done everyday. After about 200 shots of coffee a thorough clean should be done with the appropriate espresso machine cleaning detergent or powder. We like to use Urnex Cafiza.
If you are a commercial shop then a backflush using cleaner should be performed once at the end of each business day, you may choose to backflush during the day without chemical depending on your volumes.
Can I Backflush My Machine?
Not all Espresso Machines are capable of being backflushed so it is important to know whether your machine can before trying. Espresso Machines must be fitted with a 3-Way Over Pressure Valve to be able to backflush. Many entry level consumer machines are not fitted with these and you often need to move into higher end home espresso machines to get this feature, check your manual or with the manufacturer if you are unsure about your particular machine.
The purpose of this valve is to remove the excess pressure and moisture at the end of the shot helping to avoid a ‘soupy puck’ making it easier to remove from the portafilter. Since this valve controls the flow of water to the grouphead, it also prevents dripping that can be found on some of the entry level machines.
How to Backflush My Machine?
- Remove the portafilter basket and replace with a blank portafilter basket, i.e. basket without a screen, also called a blind basket, some manufacturers provide a blank rubber disk that will perform the same function.
- Put approximately half a teaspoon of espresso machine cleaning detergent into the blank portafilter basket.
- Insert the portafilter into the grouphead of your espresso machine securely, and start the pump as if you were extracting espresso. After roughly 10 seconds this will cause water to back up and build pressure. Now release the pressure by turning off the pump and the water will flush through the grouphead via a three-way valve, ending in the drip tray in the machine.
- Backflush with the detergent a few times, using 10 second intervals. Remove the blind basket and you will see the detergent and coffee oils present. Make sure that the grouphead has been flushed thoroughly.
- Remove and rinse the portafilter and basket using water from the grouphead. Make sure to run water through the grouphead.
- Once the machine is clean of detergent, backflush the grouphead a few times without detergent to remove any residual detergent.
- Use a grouphead cleaning brush to remove any residual coffee grounds and oils from the grouphead and gasket. Also scrub the dispersion screen. After brushing, use a wet terry towel to clean off the gasket and around the sides of the dispersion screen and grouphead.
- If possible, remove the shower screen and soak in detergent and hot water to remove caked-on coffee residue and grinds.
- Once again, remove the portafilter and rinse the grouphead clean. Replace the blank portafilter basket with a normal filter basket.
- To season the grouphead, and to ensure that there is no detergent residue, pull one or two shots through each grouphead that has been cleaned.
Other Uses for Espresso Machine Cleaning Detergent
- Soak shower screen, baskets, water spreaders, portafilter handles and various other metals for 30 minutes in 1 teaspoon of espresso machine detergent per 500 mL of hot water.
- Rinse with clean hot water.
Mix 1 teaspoon of espresso machine detergent per 500 mL of hot water and pour into a spray bottle. Use the spray bottle to clean various parts such a strip trays, steam wands, espresso machine body panels, grinders, knock boxes and countertops.