If you’ve ever splattered your face, shirt, counter, and ceiling with coffee and grounds when trying to operate an Aeropress coffee maker, this is how to prevent it.

Blowouts happen when it takes so much force to push the water through the coffee grounds that the seal around the plunger breaks, and the coffee takes the path of lower resistance, and ends up in your face rather than in your cup.

Sometimes, this is because the plunger is old and worn, and the seal isn't as good as it used to be. But this is usually just one contributing factor.

More likely it’s the result of using too much grounds, grinding the coffee too fine — or both.

However, I like my coffee strong and espresso-like, so I stubbornly over-grind and over-load my Aeropress even though I know it increases the probability of excitement.

Fortunately, there’s a solution. Instead of thinking of it as putting downward pressure on the coffee, think of yourself as resisting upward pressure from the compressed air and water.

If you press down “through” the Aeropress toward the cup, counter, or centre of the earth, that means when the resistance disappears (ie, the seal breaks) the plunger will move rapidly to its terminus and blow coffee everywhere.

Instead, press the plunger maybe a half-centimetre farther down. Think of that as the “goal”. When you have reached the goal, hold the plunger in place, keeping it from coming back up. Pretend to compress the air, and let the compressed air force the water through the coffee while you hold still. When the resistance reduces, repeat.

This means if — or rather, when — the seal around the plunger breaks, there is a fixed amount of built-up pressure. It might spritz a wee bit of coffee and grounds up the side of the plunger, but there won't be enough pressure to decorate the ceiling.

(Note: this Jedi mind trick works any time you are putting pressure on resistance that may suddenly disappear.)

I brace both hands and plunger against my chest, with the intent that all three remain still if the seal breaks. Even with this trick, I clear the counter around the Aeropress, and keep my face out of the blast zone.

Most blowouts happen at the start of the plunge, because that's often when a) the seal is partly dry, b) there are coffee grounds breaking the seal, c) there’s an air pocket between the plunger and the grounds slurry, and d) the plunger is most likely to be crooked. You can often hear a hiss when the seal is about the break. Start slow and gentle, and then increase pressure at the end.

I hope this helps someone.