Brighter beer days foreseen
Words Gabriela Lee

Part of the process of making beer is the process of filtration. Traditionally, freshly brewed beer are processed through conventional beer filters made of either densely packed fibers or a dusty material called kieselguhr, which are made up of fossilised hard-wall algae called diatoms. Usually, the passages through the filter are long and tortuous, and vary enormously in width, so they can demand pumping pressures nearing one atmosphere. Furthermore, kieselguhr can be a health hazard if not handled properly and carefully.

But now, using technology developed in the early 1990s by Philips for the creation of CD-quality sounding cassette tapes (known as DCC or Digital Compact Cassette tapes), a new class of fluid filters is being tested by Dutch company Fluxxion that is made up of silicon wafers blasted through by beams of hot flurocarbons - the same process used to make microchips. Each silicon wafer measures about 15 cm and contains about three billion 0.45-cm holes made by plasma beams in a vacuum. The silicon filters have short passages of consistent and precisely-controlled sizes, so the pressure used is about one-tenth of conventional beer filters.

Fluxxion is also testing their filters for milk to see if it can remove bacteria and skip the process of pasteurization, which impairs the taste. Furthermore, they are also trying to see if it can be used to filter blood plasma to remove viruses.