A method of destroying, or inactivating, microorganisms in liquids using high frequency near infrared lasers is described together with its experimental application as an alternative to the conventional pasteurization of beer. Treated beer samples had average yeast cell counts three times less and bacterial cell counts seventeen times less than control samples. The fact that the treatment is less effective against yeasts means that it can safely be used to remove any spoilage bacteria that may be present in beers intended for bottle or cask conditioning while still leaving a sufficient number of viable yeast cells to carry out secondary fermentation in the trade container. The intensity of the lasers is only slightly reduced by passing through glass or the plastics used for bottles and beverage pipes, so it can be applied to beer after bottling or before canning, kegging or cask racking. The laser treatment does not cause molecular ionization (unlike some other forms of food/beverage irradiation) and appears to have no detrimental effects on beer quality (whereas conventional pasteurization can cause off flavours unless very precisely controlled, while sterile filtration can only guarantee the removal of all microorganisms by using filters so fine that they may also remove desirable flavour/mouthfeel constituents). It is also claimed to be considerably cheaper than either pasteurization or sterile filtration
