World Barista Championship contenders really push the boundaries...
When you read the titles of my weekly blog do you think I'm totally nuts? You can be honest.
This week's topic is particularly nutso, and very interesting, at least to me. The World Barista Championships are a treasure trove of interest as contenders try lots of different techniques to gain any edge they can. Ben Put first used the technique of fractional distillation of milk in the 2017 championship. Let's dive into the rabbit hole...
When I think of distillation, my first thought is for spirits... specifically whisky. Distillation allows for the separation of different parts of the alcohol ferment according to the temperature at which phase change occurs (in this case temperature is increased and liquids become gases). Alcohol becomes a gas relatively early compared to most other compounds in the initial fermentation of spirits. The alcohol and other relatively volatile compounds are progressively condensed in a series of distillations until those components become highly concentrated. For whisky, alcohol content starts at 8-10% in the initial fermentation and tends towards 67% by the end of a number of separate distillations.
Distillation of milk is interestingly different. The main components of milk are water, sugars, proteins and fats. You can separate out milk using similar techniques to distillation of spirits, by adding heat, but the heat itself irreversibly alters the nature of the sugars, proteins and fats so that the distilled milk product tastes different from the milk you are used to. I hadn't thought about it before doing some research on the topic, but you can distill a liquid in a completely different way. Instead of adding heat you can drive phase change by removing heat! Different components of the liquid freeze at different points and therefore you can alter the composition of milk, without fundamentally changing the components and flavour compounds, by freezing it. The highest freezing point component of milk is water and so if you get the milk to the correct temperature the water will freeze and you can remove the interesting parts of the solution at higher concentration levels... producing an intensified version of milk.
I've been doing this recently and the result is milk coffee which feels and tastes extremely luxurious. It's perhaps a 10-15% improvement so it's not a night and day difference, however the sense of occasion you experience with this process is definitely noticeable, and quite wonderful.
Here's the exact process I use. Grab a one litre bottle of milk, pour out a small amount of milk and use however you see fit, you'll remember that when water freezes its density decreases and volume increases so if you don't remove that small amount of milk you might find that the bottle explodes after freezing! Put the bottle in the freezer and wait a couple of hours. At this point you'll likely find that some of the milk has frozen. If it hasn't frozen enough then wait longer, if it's completely frozen then you need to put it back in the refrigerator and wait. You can simply pour out the unfrozen part of the liquid into a different container which you then use as you would normally do for your milk coffee. I find that the yield I'm achieving is roughly 60% of the original volume.
Please let me know what you think if you try this method.
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