Thread by @mamboitaliano__

One of the smallest yet most brilliant and delicious Italian 🇮🇹 inventions of all time

How the Moka works

A Thread 🧵

Henry Darcy, a French engineer and expert in hydraulics, is famous for Darcy’s law, formulated in 1856

It describes how fluid flows through a porous material depending on pressure differences, permeability, thickness, and viscosity

Fast forward to 1933: Italian engineer Alfonso Bialetti invented the moka pot

Thanks to Darcy’s law, his invention works perfectly and still sits in kitchens worldwide

We all know what a moka looks like

But how does it work?

When you fill the water chamber and heat it, a pressure difference forms across the coffee grounds

Steam pressure below is higher than atmospheric pressure above, forcing water up through the coffee and extracting all its aroma

Essentially, it’s a mini filtration system — just like the flows Darcy studied in sand and gravel back in the lab

So, how do we make the perfect cup of coffee? It all comes down to flow — how fast water moves through the coffee:

•If it’s too fast → weak coffee

•If it’s too slow → strong, maybe even bitter coffee

The trick? Adjust how you pack the coffee grounds

•Press harder → less space between particles → slower flow → stronger coffee

•Press lighter → more space → faster flow → lighter coffee

The sweet spot is somewhere in the middle

Fun fact: the coffee rising process has even been filmed at the Paul Scherrer Institute in Switzerland using neutron imaging

Science and coffee, perfectly combined!

A lot of time has passed since Bialetti, and mass production has also changed the method and the ritual…

But the association of the moka with Made in Italy will remain forever in the collective imagination

And how do you like your coffee?

Do you still use the classic moka pot, or have you switched to modern machines? ☕️

Bonus

One last small tribute to this invention, because it truly embodies Italy 🇮🇹

Its aroma, aesthetics, memories, experience, ritual, and moments of our lives

Thank you so much, Alfonso Bialetti!