It’s 10:15 a.m. and you just pulled the last doppio ristretto of a grueling morning rush. The next thing you know, the boss walks in and orders a double straight-up, and you’re happy to oblige. After all, you’ve been pouring consistent, amazing shots since early in the morning. Outside of the two or three you had to re-make, your extractions have boasted beautiful reddish-brown persistent crema with just the right amount of flecking. As you pass the espresso coffee past your nose, your olfactory system picks up the aromatics of fruit, caramel and chocolate: the shots are dropping heavenly today.

You say, “Coming right up!” and diligently rinse the portafilter under the hot water spout and wipe it clean. Then you throw it back up on the grouphead to make sure it stabilizes its temperature. While the portafilter is chillin’ out up on the group, you grind and purge a little coffee through to make sure you are rolling fresh for the boss’ espresso. Following all of that, you precisely dose, level and tamp the coffee into the filter basket and once again, a flawless pull ... or so you think. The boss takes a whiff and seems to give a nod of approval. He tips back the demitasse, chews it around for a second and politely says, “That was pretty good.” Pretty good? you think. As he walks off, you decide to pull one for yourself. It smells great for sure, but you take a sip and the clarity in the flavors you expected just isn’t there. The cause? Most likely it’s a dirty grouphead and portafilter.

Good Morning

After rinsing out your crema-stained shot glasses, brushing the grounds off your counter top, and cleaning up your drip tray, you should start thinking about the mess that is often overlooked but is most critical to your work: the dirty grouphead and portafilter. As you were jetting through your line of customers, dropping double shots for every Americano and latte that came through, those volatile little coffee oils that can offer so much goodness when they’re fresh have now become a severe barrier to all the wonderful components in a good shot of espresso. They have had time to build up and burn on the exposed surfaces of your grouphead and portafilter. So it doesn’t matter if you’re pulling the best shots of your life; if you don’t clean out those old remnants of the crema, the shots are going to taste just like the bar towel hanging from your apron. Cleaning the grouphead and portafilter properly might seem intimidating, but there are a few steps you can take to give you confidence that the shots will be as good as they can be, without the hint of burnt tar that will clog up one’s taste buds: mid-shift backflushing.

The process of mid-shift backflushing should only take you a few minutes, but it’s important to determine a reasonable time to do it. To allow yourself enough time to do it thoroughly, pick a typically slow time in your day. Once you can gauge this, try to set a schedule with the rest of the staff so you can make sure mid-shift backflushing is happening regularly. In a perfect world, an espresso machine in a busy café should be back flushed every 60 to 90 minutes, all day, every day. Not only will this prevent your drink quality from suffering, it will also make the end of the day cleaning easier. An important note: Never use detergent to do a mid-shift backflush.

Start the process by getting the appropriate tools ready: blind portafilters or filter baskets, a small Scotch-Brite scrub pad square, and a brush to clean the grouphead (the Pällo Coffeetool is our favorite). Also, fill some sort of container with hot water in which to soak the portafilters. It is best to have everything ready to ensure a speedy but efficient cleaning. Remove the dirty portafilters from your machine, pop out the filter baskets, and place them in the hot water to soak. Soaking them in the hot water will make the removal of the oils easier once you start scrubbing. Let the portafilters soak while you tackle the mess that is in the grouphead.

There are a lot of old, wet coffee grounds that have built up around gasket in the grouphead. Start by giving the gasket and screen a good once over with your nylon group head brush. After that, insert the blind portafilter in the grouphead, start the brew cycle, and then rapidly remove/insert the portafilter as the water is running. This helps break up the little clusters of old coffee that have built up in the gasket. After the water is running relatively clear, use your brush to scrub any remaining grounds or visible coffee oils. Once the grouphead looks clean, insert the blind portafilter and run the brew cycle for five seconds on and 10 seconds off. Repeat that two times, then empty the water in the blind portafilter, re-insert and move on to cleaning the dirty portafilters.

A significant amount of the messy oils will have lifted off the portafilters while they were soaking, but you want to make sure you get them all. Take your scrub pad, and under warm running water, scrub out all the visible oils stuck to the interior and exterior surfaces of the portafilter. Rub the filter baskets clean with your hands but do not use your green scrubby, as it can widen the filter basket holes over time. The portafilters should look somewhat close to the way they did at the beginning of the day. Pop the filter baskets back into the portafilters and put the portafilters back into the machine.

Now you have clean portafilters and a clean grouphead with which to brew your espresso. The only unfortunate drawback of mid-shift backflushing is that it significantly upsets the temperature stability of both the grouphead and portafilter, which we all know is critical in espresso preparation. The best way to get the temperature back on track is to pull a shot through each group head. This will also tell you if the grind is in need of adjustment.

Want to know what to do next? Then order this back issue today from Barista Magazine!