Is Pre-Infusion Really Important for Espresso? A Simple Guide to Better Extraction

 A while ago, a friend of mine updated his La Marzocco Home App, and he turned off the pre-infusion function. I asked him why he did that, and he said it felt useless. After I emphasized how important pre-infusion is, he quietly turned the setting back on. Haha. That little incident gave me an idea—why not make a post dedicated to talking about the importance of pre-infusion?

To be honest, whether pre-infusion is truly important doesn’t seem to have a single absolute answer. For people chasing the ultimate flavor in espresso, it’s a core variable. But for someone who simply wants a stable, decent cup of coffee, it’s just another machine parameter.

Before we decide whether it’s important or not, we should first understand what pre-infusion actually is and what role it plays during espresso extraction.

Simply put, you can think of pre-infusion as watering a dry sponge. If you skip pre-infusion and start extraction right away, high-pressure water blasts through the coffee puck immediately. The water doesn’t have time to fully absorb—it rushes through quickly. The surface of the sponge gets wet, but the inside remains dry.

With proper pre-infusion, however, a small amount of water first wets the puck. After a few seconds, continuous water flow follows. The sponge gradually absorbs water evenly from the inside out.

This analogy makes it easier to understand one of the biggest benefits of pre-infusion: reducing channeling. High-pressure water naturally looks for the easiest path. If the coffee puck has cracks or uneven density, the water will concentrate in those weak points, causing parts of the coffee to be over-extracted while others remain under-extracted. Low-pressure pre-infusion allows water to slowly saturate the entire puck, giving the coffee bed time to “self-adjust” before full pressure is applied.

Another important factor is freshly roasted coffee beans. Fresh beans contain a large amount of carbon dioxide. If you immediately apply high pressure, the gas can block proper contact between water and the coffee grounds. During pre-infusion, low-pressure water enters slowly and allows gas to escape, making it easier for water to penetrate the puck during the main extraction.

A well-controlled pre-infusion can also reduce sharp acidity and harshness while increasing sweetness and roundness in the cup. This effect is especially noticeable with light-roasted beans, which tend to have higher density and stronger gas release.

Of course, if the pre-infusion time is too long, it may start dissolving undesirable flavors too early. In most cases, depending on the beans, a pre-infusion time of around 5–10 seconds works well.

At this point, some people might wonder: many coffee machines don’t even have a pre-infusion function. If it’s not standard, does that mean it isn’t that important?

The main reason many entry-level home espresso machines don’t include pre-infusion is cost. Developing and implementing this feature adds complexity, and for most home users, the educational and knowledge barrier is relatively high. In other words, many consumers either don’t know about it or don’t care much about it. When consumer awareness is low, manufacturers naturally have less incentive to invest heavily in it.

However, if you look at higher-end espresso machines, you’ll find that pre-infusion is almost always included. It’s one of those features that represents an “invisible improvement”—something that quietly enhances the quality of extraction.

So what if your home machine doesn’t have a dedicated pre-infusion function?

There’s actually a simple and low-cost workaround. Turn on the pump for 3–5 seconds, then stop it. Wait about 10 seconds, and then start the extraction again. This simple method can mimic a basic form of pre-infusion.

On high-end commercial machines, the system often includes a gradual pressure ramp, segmented pre-infusion stages, or even ultra-low-pressure pre-infusion, where water almost gently seeps into the puck.

Some fully automatic machines simulate pre-infusion by briefly pausing after wetting the grounds, although their pressure curves are fixed and cannot be finely adjusted.

In the end, pre-infusion is not a mandatory step in espresso extraction, nor is it some kind of magic solution. But using it more often can help ensure that when high pressure is applied, the water meets a coffee puck that is already evenly saturated and prepared—rather than blasting directly into something like a completely dry sponge.