26 March 2008

Buchi RotaVapor

Close up of the condenser chamber.....

Class Magazine May 2008 Rota Vapor Article

I remember the first time I saw the Rota vapour a couple of years ago at the lab at Fat Duck, at first I thought that it looks like it has all the components of a still on a small scale. I remember going through a mental checklist; thinking it has a condenser, it has an evaporation bulb and a receiver, but what is all the other stuff? After numerous questions and a few trails on it I realized that this was a machine for me! The possibilities it would, and has opened, are incredible for a bartender. It has allowed me to incorporate flavours I had previously found impossible to use.

The Rota Vapour (the name of the particular make I use)is in essence a vacuum still, this implies that you can distil things at lower pressures, therefore allowing you to boil your liquids to condensation at lower temperatures. This is enabled as the whole unit is a closed chamber with a pump which sucks the air out, the chamber is regulated by a digital control panel. An example of how this works; if you look at mountaineers on Everest, when they boil water it will boil at 69 degrees as the pressure is a lot lower due to the height. The advantage for this is, if you can boil samples in liquid at a lower temperature; for example, herbs for which high temperature will damage the volatiles, you can add less heat and the volatiles will not get damaged. Another good example of this is in Shochu distilling. In some instances you have very delicate rice notes which are preserved more when distilled at low pressure, you also find this happening a lot in the perfume industry where they have very delicate volatiles.

In practical terms this has allowed me to distil the essence of numerous herbs, flowers, zests and fruits that had previously been difficult to obtain. One particularly successful method I have found is to marinate my subject in alcohol, then distil the alcohol off,
leaving the essence of the plant which the alcohol has extracted in the evaporating bulb. I have found that more often than not what is left behind in the bulb is just as
good as what is in the evaporated end. This is how I started making tinctures, which I can add to bottles of alcohol as a hint of flavour, or in drinks doing roughly the same job.

You can also redistill spirits to add flavour, so for example you can put your flavour in with the spirit and evaporate it all off. So what you get in the receiving end of the rotavapor is the redistilled spirit with the volatiles and flavour perfectly incorporated to the spirit.
It is completely clear as all the vegetal mass is left in the evaporating bulb.

The heat source is a Bain Marie with an electronic temperature gauge. As a point of interest the Bain Marie was invented by an alchemist called Maria the Jewess from Alexandria in 100 b.c.
As with a lot of this equipment, this is just the high tech version of what alchemists/distillers have been using for hundreds of years, this by comparison is just very very accurate. This machinery deserves accuracy in return to obtain the best results, I find it best to write everything down, as even small variances can produce very different results, so keeping a log I found to be the best method of getting consistent results. It really does place a lot of emphasis back in the hands of the bartender as you don’t have to wait for a drinks company to invent such and such flavoured spirit; its more a question of this week I will be making!!!

There are other stills you can use from different companies and costs but I have found this to be the most complete BUCHI R210.

Further information contact BUCHI on 01616331000.

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