When pouring water into dry coffee, it will naturally find a path with less resistance and start flowing through. When this happens easily, we refer to it as a good extraction: the coffee is evenly (and thoroughly) extracted or brewed.

It can happen, though, that because the coffee bed is uneven, this process is hindered or interrupted altogether. The coffee bed may not be evenly tucked, or the grind isn’t even. And so, we may get too much resistance, meaning that the flow of water is erratic. In other words, it results in bad coffee. 

Pre-infusion is the perfect way to foolproof your coffee bed. It naturally evens out the coffee bed; lightly soaking the grounds moves things around, helps the grounds expand. A simple taste test that you can do at home with coffee brewed using pre-infusion and without, the results will be shockingly clear: pre-infusion makes coffee taste better.

Espresso machines

As we mentioned earlier, the “pre-infusion feature” is a very popular sentence. But, the truth is, all espresso machines are supposed to pre-infuse your coffee!

This goes back to the legendary espresso machine Faema e61, which came out in the 60s. The machine itself incorporated a series of features that made it a hit, and most espresso machines nowadays share blood with this iconic machine.  

The Faema e61 came with a pre-infusion feature that worked thanks to its unique grouphead. It would let a small amount of brewing water -just enough to get the coffee grounds wet- before the actual extraction.  

Since then, most coffee machines have followed its example. So, even if an espresso machine boasts of having a “pre-infusion feature”, well… That’s kind of the bare minimum. 

But still, it’s something to look out for. Some espresso machines do put more emphasis on this feature and have a better approach to it than others.

Semi and manual espresso machines may not have a way to pre-infuse your grounds. Which means that you might have to do it yourself.  

To pre-infuse, it's a good idea to use water that's hot, but not so much that it will brew the coffee. 70 degrees Celsius is a good number. 

The amount of water used will vary depending on the amount of coffee you're brewing; pour water very slowly, little by little. This will let you visually see when all the grounds have been saturated and stop before you use too much water. 

After pre-infusing, attach the grouphead right away. While the duration of a pre-infusion is a subjective matter, longer than 30 seconds could potentially add negative flavors to your coffee.

Most Americans still get their daily coffee fix using a good ol’ coffee machine. These aren’t particularly good for quality, so pre-infusion is actually a great way of getting better flavor on otherwise mediocre coffee.

Take the basket out of the machine, then proceed to wet the grounds. Then, and only then, you can place it in the machine. It might be a bit messy, but it’s the only way to do it. 

There are now fancier drip coffee machines that actually do pre-infuse their grounds, so if you have the chance and means to, definitely look for ones that have a pre-infusion feature.

Light roasts

Here, pre-infusion is one of the best things you can do. Because the roast has barely toasted the grounds, there is very little risk of an overextraction that will result in burnt flavors.  

So, light roasts like a good pre-infusion and you can easily try for longer pre-infusions; chances are it will help develop even more flavor without really affecting the overall flavor in any negative way. 

Medium roasts

Rules of thumb apply very strictly when it comes to medium roasts; go under or over the recommended temperatures and times, even for one second, and you will notice off flavors in the cup.  

If possible at all, leave pre-infusions here to your espresso machine as much as you can. They are always engineered around medium roasts, so their standard settings are most of the time spot-on for most of these coffees.

Dark roasts

High risk and high reward, pre-infusion in dark roasts is a bit of a wild card. Even if you stick to every single instruction to a particular coffee, it might still come out wrong.  

Why? Because dark roasts already have negative flavors in them. The magic is that they are balanced. A bad pre-infusion (and even a regular one) can throw off the whole balance and bring negative flavors to the surface.  

When done correctly, however, the resulting flavor is sublime. But it is highly recommended that you only try pre-infusing dark roasts when you’ve already got plenty of experience. Otherwise, refrain altogether, as you might just end up with undrinkable coffee.