Pay Attention to These Details When Making Espresso! Why Do You Need to Prime an Espresso Machine? How to Clean Your Coffee Machine?

FrontStreet Coffee has shared plenty of small details to watch when pulling espresso, but those earlier pieces focused mainly on factors with a big influence on extraction, such as parameters and distribution. Today we want to look at a few operational habits that are easy to overlook.

These may not matter as much as the big factors, but their cumulative effect over time is not to be underestimated. So let's run through the details worth paying attention to when you extract espresso.

1. Not flushing the group before locking in the portafilter

Before locking in the portafilter, baristas usually open the water valve and flush hot water first.

The reason is that hot water travels from the tank to the brew head through a long stretch of piping, where water from the previous extraction may still be sitting. Having been left standing longer, it carries more unstable factors than fresh water in the boiler: it is cooler and less clean. So we flush first and then extract with completely fresh hot water. At the same time, the flush helps cool an overheated dispersion screen while washing away any coffee residue that was not fully cleaned. A few seconds at the water valve buys all of these advantages, so there is no reason to skip it.

2. Leaving the portafilter attached for a long time after extraction

Often, once the shot is pulled we move straight on to the drink we actually want, a latte or an Americano, and then enjoy it, completely forgetting the portafilter still attached to the brew head. Left there long enough, this only makes cleaning harder.

When extraction ends, the brew head draws back the hot water remaining in the portafilter through backflushing, then discharges it through the pressure relief valve. What gets drawn up, however, is not only the hot water that did not make it through, but also some coffee grounds.

When grounds are pulled up by the backflush, they stick to the dispersion screen. Those fine particles keep being baked by the heat radiating from the screen. Once the moisture dries completely, they take on a burnt taste and cling even harder. The same happens to the puck in the portafilter. In just a few minutes the moisture in the puck dries out and its adhesion strengthens. Knocking it out then takes more effort than usual, and the stronger grip makes cleaning more troublesome. So if you are a little forgetful, as we are at FrontStreet Coffee, the best habit is to remove the portafilter right after the shot, knock out the puck, and only then continue with the rest of your routine.

3. Keeping the portafilter locked in the group for long periods

Many people leave the portafilter in the brew head to keep it warm between shots, hoping to reduce inconsistency when serving. But this very habit makes it easier to forget the un-removed puck. After all, once the portafilter is in place we cannot tell by eye whether the machine is in extraction mode or merely holding heat.

It also brings two downsides. The first affects extraction. Aroma compounds in coffee are volatile and evaporate more readily in high heat. If we extract with a preheated portafilter, the moment the grounds are dosed the loss of aromatics accelerates sharply. If something delays your shot at that point, you easily end up with an espresso whose flavor has drifted.

The second is more important: this practice damages the gasket. Inside the dispersion screen there is a gasket that secures the portafilter and keeps coffee liquid from leaking. If we always keep the portafilter in place for warmth, the heat that should be released continuously is trapped and can only escape slowly through the gaps around the portafilter. The result may be a warmer portafilter, but the circulating heat with nowhere to go keeps baking the gasket and speeds its aging. So it is better not to leave the portafilter locked in the group. If you want to keep it warm, simply flush hot water to preheat it before you extract. That also cleans the dispersion screen and removes grounds stuck in it, solving two problems at once.

4. Not cleaning the brew head regularly

After extraction we flush water to wash away the grounds left on the dispersion screen, but the gaps around the screen, where the portafilter attaches, are out of reach of the flush and retain coffee residue. After several extractions, it is worth using a brush made for espresso machines to clean those gaps, so that when you lock in the portafilter, excess fine grounds will not fall in from above.

Specifically, open the water valve to flush while scrubbing with the brush under the hot water.

FrontStreet Coffee Recommendation

Clean technique only pays off with beans that suit espresso, and milk drinks in particular reward a blend with body and a generous crema. FrontStreet Classic Blend is made for both espresso and the Moka pot, and its standout strength is crema: even a beginner with an ordinary home machine can pull a dense, fine foam. Built on the traditional Mamba recipe, it tastes rich and mellow, easy for veterans and newcomers alike, and works well at home or in a cafe.

If you would rather not chase maximum crema, FrontStreet Dark Cocoa Blend is a strong value. It is 100 percent Arabica with ample crema and a full body at a friendly price, a sensible pick for anyone opening a shop or watching costs. FrontStreet Specialty Blend is the espresso blend our own shops have used the longest, nearly a decade, combining Brazil Cerrado and Colombia Huila for the classic Italian profile most people picture when they think of espresso.

Whichever blend you choose, remember the two habits above: flush before you lock in, and pull the portafilter and knock out the puck the moment the shot is done.