Spinning cone columns are used in a form of steam distillation

Steam distillation

Steam distillation is a special type of distillation for temperature sensitive materials like natural aromatic compounds....

 to gently extract volatile chemicals from liquid foodstuffs while minimising the effect on the taste of the product. For instance, the columns can be used to remove some of the alcohol

Alcohol

In chemistry, an alcohol is an organic compound in which the hydroxy functional group is bound to a carbon atom. In particular, this carbon center should be saturated, having single bonds to three other atoms....

 from wine, 'off' smells from cream, and to capture aroma compound

Aroma compound

An aroma compound, also known as odorant, aroma, fragrance or flavor, is a chemical compound that has a smell or odor...

s that would otherwise be lost in coffee processing

Coffee processing

Processing of coffee is the method converting the raw fruit of the coffee plant into the coffee. The cherry has the fruit or pulp removed leaving the seed or bean which is then dried...

.

Mechanism

The columns are made of stainless steel. Conical vanes are attached alternately to the wall of the column and to a central rotating shaft. The product is poured in at the top under vacuum, and steam is pumped into the column from below. The vanes provide a large surface area over which volatile compounds can evaporate into the steam, and the rotation ensures a thin layer of the product is constantly moved over the moving cone. It typically takes 20 seconds for the liquid to move through the column, and industrial columns might process 16-160 litres per minute. The temperature and pressure can be adjusted depending on the compounds targeted.

Wine controversy

Improvements in viticulture

Viticulture

Viticulture is the science, production and study of grapes which deals with the series of events that occur in the vineyard. When the grapes are used for winemaking, it is also known as viniculture...

 and warmer vintages have led to increasing levels of sugar in wine grapes, which have translated to higher levels of alcohol - which can reach over 15% ABV

Alcohol by volume

Alcohol by volume is a standard measure of how much alcohol is contained in an alcoholic beverage .The ABV standard is used worldwide....

 in Zinfandel

Zinfandel

Zinfandel is a variety of red grape planted in over 10 percent of California vineyards. DNA fingerprinting revealed that it is genetically equivalent to the Croatian grape Crljenak Kaštelanski, and also the Primitivo variety traditionally grown in Puglia , where it was introduced in the 18th century...

s from California

California wine

California wine has a long and continuing history, and in the late twentieth century became recognized as producing some of the world's finest wine. While wine is made in all fifty U.S. states, up to 90% of American wine is produced in the state...

. Some producers feel that this unbalances their wine, and use spinning cones to reduce the alcohol by 1-2 percentage points. In this case the wine is passed through the column once to distil out the most volatile aroma compounds which are then put to one side whilst the wine goes through the column a second time at higher temperature to extract some of the alcohol. The aroma compounds are then mixed back into the wine. However some producers such as Joel Peterson of Ravenswood argue that technological 'fixes' such as spinning cones remove a sense of terroir

Terroir

Terroir comes from the word terre "land". It was originally a French term in wine, coffee and tea used to denote the special characteristics that the geography, geology and climate of a certain place bestowed upon particular varieties...

 from the wine; if the wine has the tannins and other components to balance 15% alcohol, Peterson argues that it should be accepted on its own terms.

The use of spinning cones, and other technologies such as reverse osmosis, is banned in the EU, although they can be used in wines imported into the EU. In November 2007, the Wine Standards Branch (WSB) of the UK's Food Standards Agency

Food Standards Agency

The Food Standards Agency is a non-ministerial government department of the Government of the United Kingdom. It is responsible for protecting public health in relation to food throughout the United Kingdom and is led by a board appointed to act in the public interest...

banned the sale of a wine called Sovio, made from Spanish grapes that would normally produce wines of 14% ABV. Sovio runs 40-50% of the wine over spinning cones to reduce the alcohol content to 8%, which means that under EU law it cannot be sold as wine as it is below 8.5%; above that it would be banned because spinning cones cannot be used in EU winemaking.

External links

• FT Technologies (formerly Flavourtech), a column manufacturer, has some good information and diagrams of how the columns work.
• ConeTech, Inc is a large manufacturer of spinning cone columns.