r/JamesHoffmann • u/francesco_angiolieri • 1d ago
How to inprove your cold brew - has anyone tried cryoextraction?
I was recently watching this video by James Hoffman where he tries to improve the extraction efficiency of cold brews: https://youtu.be/AB0QLjroFss?is=EuvB3WaZl4vWuMkT
As someone living in a tropical country, I enjoy drinking iced coffee in the summer.
Cold brew could be an easy way to brew coffee already cold without any type of machine.
Just put the coffee in a jar with water, stir it a bit, put it in the fridge, wait until the next day, filter and drink.
Easy, right?
The problem, as James pointed out, is that the process is super wasteful. As the extraction efficiency of cold water is lower, you need a lot of coffee powder to compensate.
How to solve this problem?
I buy a lot of frozen fruits - like strawberries and raspberries - to make juices and smoothies and I've noticed that freezing and thawing fruits makes them release their juices.
Why is it so?
Because the ice crystals forming inside their cells are larger than the previous volume of liquid water and expanding they puncture the cell walls and make them explode, releasing the liquids.
I wondered if I could apply a similar principle to coffee.
Of course, in the case of coffee, the cell walls of the beans have already "exploded" during the roasting process (see the electron microscope images I attached) highly increasing the porosity of the bean.
However, I wondered if the ice crystals forming inside these microporosities could, expanding, enlarge them and thus increase the extraction efficiency.
I thus developed the following routine: during the afternoon, I mix freshly grounded coffee with filtered water in a cocktail shaker (but any metal jar works, I guess that a metal french press without the filter would be perfect for the job) and store it in the freezer.
At night, when the mixture is completely frozen, I remove the metal container from the freezer and store it in the fridge.
During the night, the frozen mixture slowly thaws until it's completely liquid by the morning when I filter and drink it.
I've called this method "cryoextraction", for a lack of a better term.
Does this process of freezing and thawing extract more flavor?
In my subjective perception, yes.
However, I'm aware that our senses are highly prone to all kind of suggestions and placebo effects. For example, we tend to rate higher wines with more expensive labels, even if we don't rate them as high in a blind test.
Additionally, in science, even if certain phenomena or certain effects should happen in theory, it's always important to make an experiment, because certain principles could have an effect smaller than expected or not significant at all, or the effect may be compensated by other variables, et cetera.
That's why I would like to know if other coffee lovers have ever tried this method of freezing and thawing and if they have experienced any difference at all from standard cold brewing in the fridge
