Coffee tips to make the best infusion at home
Storing the grain grinding, here is how to get the cup of coolest coffee at home.
Solved problems, examined
- A group of researchers in mechanics and physics at the University of Pennsylvania has created what they believe to be the best coffee technique to pay.
- The key is to use a goose -collar kettle and a large flow to make an “avalanche” in the ground coffee.
- The technique leads to the maximum quantity of coffee flavor extracted from the minimum quantity of coffee beans.
Coffee prices have significantly enriched Over the past four years, bad weather has reduced production. Add growing prices on coffee producing countries Like Brazil and Columbia, and this cup of Joe looks more and more like a luxury in the morning.
But there is a newly published technique designed to make your coffee ground go further – gracked a group of physicists and experts in slightly excited liquid mechanics at the University of Pennsylvania.
About a year ago, the staff Arnold Mathijssen laboratory I started to think about how to extract the most coffee using the least grains because they dragged on the coffee table in their laboratory. They have just published their results.
Entitled “Coffee vers-over: mix by a jet of water which prevents a granular bed with an avalanche dynamic”, their 10 -page paper in the physical newspaper of liquids was published on Tuesday.
Fluid mechanics and maximization of coffee extraction
“It started around our coffee station, which is essentially a space on one of our laboratory benches,” said Mathijssen, professor of physics at university.
One of his doctorate. Students, Ernest Park, are “the main passionate about laboratory coffee,” said Mathijssen. Laboratory coffee manufacturing devices include an espresso machine, a French press and a payment configuration. “But to sink is the drink that Ernest really likes,” he said.
A bunch of fluid mechanics experts, a laboratory full of equipment and a lot of caffeine: what could be wrong?
Or in this case: “What could be fine?”
Experience at the coffee station
Park initially started to try simply different methods for pouring boiling water into his poured cafe. Like any self -respecting scientific laboratory, the group had a logbook at the coffee station to record data on what made the best coffee.
“At the start, he just tried different things, pouring coffee from different heights. Then he said:” Wait. It has a good taste, but we have to have real experiences, “said Mathijssen.
They moved the effort to another laboratory bench and began to experiment with the size of the height of the size and water, but they realized that they needed better data to determine exactly what was going on in the coffee filter.
“We couldn’t really prove what the mechanism was,” said Mathijssen.
Coffee grounds being opaque – and a fluid mechanics laboratory being a fluid mechanical laboratory – the effort has quickly accelerated.
Soon, they had assembled a quantity of small particles of silica gel on the size of the coffee land, a transparent payment filter, a laser leaf to light up the configuration on the side and a high speed camera to allow them to film and analyze the images using a Python and Matlab computer code.
It’s all about the Avalanche coffee ground
After having made dozens of experiences and analyzed the results, Park, Mathijssen and the member of the Margot Young laboratory proposed a final technique to extract the maximum quantity of coffee at least of grains.
In scientific terms, they studied “the hydrodynamics of the cafes to be paid, in particular the way in which a liquid jet interacts with a granular bed of submerged coffee grounds”.
In simple terms, they have this advice:
- Slowly pour the boiling water over the ground coffee so that the water has more time to be in contact with the land. The longer the payment time, the greater the extraction.
- But do not pour too slowly, as it can lead to the mixture of water with the coffee grounds, which leads to part of the coffee underestimates and a little too extracted.
- Increase the payment height to increase water speed. This helps create an “avalanche” in the coffee grounds that makes them expose to boiling water as much as possible.
- Make sure the water pours in the form of a stream rather than breaking into droplets. If you pour too slowly or go too high, the stream breaks and the avalanche stops. You want to maintain a smooth and laminar water flow hitting coffee.
- A thin jet of water – the easiest product from a swan neck kettle – was the easiest way to obtain a slow laminar cast. It is possible to obtain a thin jet of a regular kettle but more difficult to do.
A slow laminar cast (which means a single flow of water and not droplets) resulted in the tastiest coffee, determined the scientists. But the last part of the experience was to test the real quantity of extract coffee solids by analyzing the dissolved compounds.
This was done by preparing cups of coffee using various heights paid and stream sizes, evaporating coffee in an oven then weighing the solid dissolved.
Does this add to the body of knowledge of science coffee?
Certainly, most Mathijssen’s research is more esoteric than that. Recent articles include “collective intercellular communication by ultra-fast hydrodynamic trigger waves” and “improving bacterial rheotaxes in non-Newtonian fluids”.
Coffee research occurred in part because during COVID-19, when their laboratory was closed, the team started a food science initiative “because it meant that we could have experiences at home,” said Mathijssen.
This resulted in articles such as “Culinary fluid mechanics and other currents in food science“Posted in 2023. They have since started Awareness of local schools To make seminars on the sciences of cooking to arouse the interest of students in physics.
For coffee experiences, a literature review has shown that there had already been research on the fluid mechanics of the Liquids involved In Expresso machines And French press coffee makers.
“But as far as we know,” said Mathijssen, “there is not yet a paid coffee.”
So far.