08 June 2011

Centrifuges




The idea of having a centrifuge behind a functioning bar, or in the back of house is probably something still quite alien to most. They have slowly made their way into the kitchens of some of the worlds top chefs and one found a home at the Drink Factory lab in 2009.

The best know, and one of the earliest centrifuges, was made by Antoni Pranotti in 1864. At the time it was used as a dairy centrifuge, to seperate milk from fat.

A centrifuge works on the Sedimentation Principle. It uses centripetal force to seperate parts of a mixture that have different densities. Meaning denser heavier liquids will fall to the bottom of each container whilst the lighter liquids will remain at the top sitting upon those liquids of a medium weight.



The current bar applications are still dependant on the same principle. For instance were you to run fresh o.j through the machine it would leave you, almost, colourless juice with no loss of flavour. Alternatively you can thin fresh purees and seperate the pulp, again, with no loss of flavour. You can apply the same principles to emulsions, cloudy liquids, or even lemon and lime.

Now, what is important to remember is, size does actually matter. The speed with which the centrifuge spins is measured in G's or RPM, (as in g-force or revolutions per minute). The big ones are used as simulators for jet pilots while the smallest are used to spin tiny test tubes. Those medium sized ones are the ones we are most concerned with. It is extremely important that the machine has enough G's or RPM to actually have an affect on the liquid. For instance our machine can reach almost 5000RPM'S which seems adequate for our purposes.

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