How do I take care of my espresso machine and grinder?
If you've recently purchased a new espresso machine or grinder, and you want them to work properly for a long time, you are going to have to take care of them. Believe it or not, proper preventative maintenance is actually the easiest part of the entire espresso making process. To start off, we will list the common tools that you will need for traditional espresso machines only. Super Automatic maintenance will be covered in a separate article. Please note that the guidelines offered in this article should always be considered supplemental to your manufacturer-issued user manual. Always follow the use and care instructions from the factory before referring to this article.
Required Maintenance Supplies
Any damp, lint-free cloth
Group Head Cleaning Brush
Urnex Cafiza for machines with 3-Way Solenoid
Blank Portafilter Basket or Insert to use with Cafiza (Make sure you buy the right size)
Urnex CleanCaf for machines without 3-Way Solenoid
Descaling Chemical NEVER USE VINEGAR
Properly treated water is recommended for any machine, especially Heat Exchanger boilers (See descaling section for more information)
Before we get to the more involved maintenance tasks of backflushing and descaling, there are some simple steps you should follow after you are done brewing espresso for any extended period of time and immediately after frothing milk. Once you have brewed all the shots of espresso you intend to make in one setting, you should perform two quick cleaning tasks. First, "brew" water through an empty portafilter to help remove ground coffee from the shower screen and lessen the amount of coffee oil that adheres to the brew group, portafilter and basket. Next, you will want to take that damp cloth and wipe the outside of the shower screen and around the brew group gasket. Performing these two simple steps requires only a few seconds but prevents coffee oils from literally baking onto the brew group and shower screen and extends the life of the brew group gasket. Keep in mind that the brew group is over 200 degrees, so take care not to burn yourself. If you've ever wondered why your first shot of the day, or after the machine has sat on and idle for hours, tastes awful, it is probably because these steps have not been done. If you have just frothed or steamed milk for a latte or cappuccino, as soon as you pull the pitcher away from the machine, you must immediately crack open the steam valve briefly to blast any residual milk from the inside of the steam pipe. If you do not do this, the steam wand will eventually clog, and it is possible for milk to find its way to the boiler on many household espresso machines. You really don't want that last part to happen. Also, immediately after blasting out steam, you should take your damp cloth and wipe the dried milk off the outside of the wand. Use a suitably thick cloth to protect your hand from the burning hot wand. If you allow the milk to linger, it will be much more difficult to clean off later. Additionally, on most single boiler (dual-purpose) home espresso machines, such as the Rancilio Silvia, you must also refill the boiler immediately after steaming. This is necessary to help prevent damage to the heating element.
Backflushing and Alternatives
If your espresso machine has a 3-Way Solenoid valve, you should backflush the brew group to clean the inner workings of built-up coffee oils. If your machine does not have one, skip ahead to the next paragraph. The 3-Way Solenoid opens its boiler-side port (1) when the brew switch is activated to allow water to move to the brew group and ground coffee (2). When the brew switch is turned off, the solenoid closes the boiler-side port and opens a pressure-relief port (3) to dump excess water pressure into your machine's drip tray. Backflushing is the process of "brewing" into a closed portafilter basket with about one half teaspoon of detergent (Urnex Cafiza). With the portafilter locked into the group, press the coffee brew switch and allow it to run for up to 5 seconds (up to 10 on rotary pump commercial machines) before shutting off the brewing process. As pressure builds, the detergent will swirl around the brew group and shower screen. When the switch is turned off, detergent-laden water will exit out of the solenoid into your drip tray. Leave the brew switch off for about 10 seconds, and repeat the process until clear and clean water runs into the drip tray. Espresso cafes that brew hundreds of shots backflush daily (sometimes twice daily). The typical 1 to 3 drinks-a-day home barista needs only to backflush with detergent every 2 to 3 weeks. Increase the frequency of backflushing to adjust for increased usage. It is also encouraged to remove and clean the metal shower screen that is part of your brew group. This is either a mesh or stamped metal screen with a bolt or screw holding it into place. For the most effective backflush, remove and soak the screen in Urnex Cafiza, and then reassemble before backflushing. While you are soaking the shower screen (and dispersion block if applicable), soak your filter baskets and portafilter to clean them up (WARNING: do not soak polished aluminum portafilters found on inexpensive espresso machines, only chrome-plated brass portafilters). If your espresso machine does not have a 3-Way Solenoid valve, attempting to backflush could damage the components, so you must go about cleaning the brew group in another way. Purchase the Urnex CleanCaf, which goes directly into your water tank. Dissolve 1 packet (each box comes with 3) into 32 ounces of warm water and pour into an empty water tank. "Brew" about 12 ounces out and allow the solution to sit in the boiler for about 20 minutes. Do this 2 more times and then rinse thoroughly with clean water. CleanCaf includes a blue dye to help you see when you have flushed all the chemical out. CleanCaf includes a mild descaler, so take care not to allow any chemical onto polished metal or chrome parts as it will eat through the finish.
Descaling / Decalcifying
The water you brew your espresso with, even when properly treated, will still include some minerals. Over time, these minerals will coat the metal parts inside your espresso machine, beginning with the heating element and including the steam valve. Depending on the hardness of the water used, descaling may be required as often as every month or as seldom as every 2 years. If you notice that your espresso machine takes considerably longer to heat up or you experience steam wand or brew group leakage, descaling should be your first troubleshooting step. To remove the minerals, you will have to use a descaling solution, which is typically made from citric and other acids. Do not use vinegar, and always use NSF-certified chemicals for food safety. The descaling process for single (dual-purpose) or double boiler espresso machines is simple, but it is much more complicated for Heat Exchanger espresso machines, which typically must be disassembled. For this reason, we strongly recommend using properly treated water to minimize the frequency of descaling procedures. Follow the mixing instructions for whichever chemical is used and pour the solution into your water tank. Follow the manufacturer directions. We also recommend pumping some of the solution out of your steam wand if possible (while partially opening and closing the valve) to extend the life of the gaskets. Again, as this solution is corrosive to certain metals, take care not to allow it to contact or splash onto any chrome or polished metal surfaces (read: don't allow your steam wand to become submerged in the expelled solution). Rinse your water tank and all internal parts thoroughly with as many as 3 tankfuls of water or until the chemical taste is gone. You'll know if it's not.
At some point in the life of your espresso machine, you are likely to have to replace some gaskets. How well you maintain your machine in the paragraphs above plays a role in dictating how frequently you will have to change gaskets. The most commonly changed gasket is the brew group gasket. This is the heavy rubber circle that is embedded in your espresso machine's brew group, and it circumscribes the shower screen. As with all rubber, it gets hard and eventually dries out and cracks when exposed to high pressure and temperature, both of which are plentiful in an espresso machine. Depending on how long you keep your espresso machine turned on throughout the day, you may replace this gasket twice a year or once every 2 years. If your machine leaks water down the outside of the portafilter when brewing, it's time to change the gasket. The other gaskets you may need to change are located in the steam valve. There is usually a heavy rubber gasket that seals off the steam pipe and one or more o-ring gaskets on the shaft of the steam tap. These should last a lot longer than the brew group gasket, but if you do not descale regularly, or if you crank down too hard all the time to close the steam valve, they will wear out more quickly.
Espresso grinder maintenance is without question the most overlooked aspect of equipment care. There is typically no harm in doing nothing, but if you want the grinder to stay in like-new condition, follow these steps. Remove the bean hopper every so often (or whenever you notice beans sticking to the walls and not falling into the grinding chamber) and clean with warm soapy water. Always allow time for the hopper to dry completely before reattaching. Remove the upper grinding burr and vacuum out loose particles. Use a completely dry, stiff nylon brush (such as your brew group brush) to knock off stubborn coffee grounds. Vacuum the discharge chute and any loose grounds you notice between the grinding chamber and the outside case. (Coffee grounds are like beach sand, they get everywhere and are hard to remove.) Reassemble your grinder and recalibrate if necessary. You can also grind the Urnex Grindz cleaning tablets to remove coffee oils from the grinding chamber. Always grind some throwaway coffee (non-flavored) to flush out the Grindz particles. When properly used (not making metal on metal noises due to grinding too finely) grinder burrs have a life of hundreds of pounds of coffee beans (over a thousand for commercial grinders). If you have brewed that much espresso, kudos to you, but it may be time to replace the burrs (typically less than $100). Dull burrs create too many fines (powder) that interfere with the proper espresso extraction. If you plan to put your grinder into storage for a while, grind some really oily beans first. The oils coat the hardened steel burrs and help protect them from rusting.