Liquid carbon dioxide as a solvent in the brewing industry.

Carroll, T.C.N. and Laws, D.R.J.

Abstract
The production and composition of hop extracts made using liquid carbon dioxide are discussed together with the economic advantages of using extracts which are rich in either essential oils or alpha acids to provide hop character and bitterness in beer. The oil rich 'aroma' fractions can be used for late addition to the kettle or injected directly into beer in solution in liquid carbon dioxide. The alpha acid rich fraction provides an excellent starting point for the preparation of isomerised extract. Both of these uses have been evaluated on a large pilot scale and several types of beer (stouts, lagers) have been brewed on a similar scale using 100% replacement of hops with liquid carbon dioxide extract. The solubility of various metal and pesticide residues in liquid carbon dioxide has also been investigated.
Keywords: beer brewing carbon dioxide extraction flavour hops hop extract pilot scale