The first time I heard the term “preinfusion,” I simply faked that I knew what it was. And I got away with it. Before I knew it, I was 2 years down the rabbit hole of Specialty Coffee, and didn’t really understand the concept at all. Maybe you’ve found yourself in a similar position? Over the last few weeks, we’ve been talking a lot about using preinfusion in relation to our decent espresso machine. And it has made a world of difference compared to doing a straight 9 bar espresso shot. So it seemed about time that I dove into the topic to fully understand it.
So what is preinfusion? Simply put, it is a method used as a way to saturate coffee grounds before completely pulling a shot of espresso. It involves soaking the puck of coffee with low pressure, low water flow, and low temperature before fully extracting and brewing the coffee puck to create espresso. The general idea is to make a more consistent flow.
Channeling happens because water finds the least path of resistance, so uneven distribution and uneven tamping can create weak points in the coffee puck which water will find and over-extract those channels. Grounds near the channels will over-extract, while grounds not in the channels will under extract. We do not want this.
Preinfusion creates an evenly saturated coffee bed to encourage water to flow evenly throughout the entire puck, which makes for a well-extracted coffee. Experimenting with variable preinfusion can lead to “nice results.”
We found that pre-infusing coffee can come in varied forms, from soft infusion to hard infusion, even to variable pressures, and different lengths of time according to Compound Coffee Co.
We also found that there is more use for preinfusion that just saturating coffee. Clive Coffee explains that methods that use preinfusion such as “flow profiling” or “pressure profiling” can be seen as a step forward in utilizing preinfusion.
This research has led me to appreciate the concept of preinfusion better. There’s really more to it than just waiting a few seconds longer than usual for the espresso shot to come out. I’m excited to explore more topics that cover the science behind specialty coffee. Maybe you have a coffee term you’d like us to expound on? Post your ideas in the comments.