Improved control of foam and haze in a range of drinks

Project title: Improved control of foam and haze in a range of drinks
Project team: Karin Pawlowsky
Running: January 2014 – December 2015
Project Number: 4300

Haze formation is a quality problem that can affect a wide range of drinks for a number of different reasons. Non-microbiological particles that can cause haze include starch, beta-glucan, proteins, lipids and crystalline substances. Controlling hazes first requires collection and analysis of the haze-causing material; this enables the cause of the haze to be identified and corrective actions can then be taken. This project will assess and develop methods for measuring and characterising hazes in beers with novel ingredients and other novel alcoholic beverages such as beer mixes (e.g. raddlers), cider/fruit mixes and spirits with novel additives. Foam is another factor of importance in the drinks industry. Excess foam during production and processing can cause serious problems; for some drinks fobbing at bottling can produce particular problems. Yet some drinks require good foam formation on dispense. This project will investigate the causes of foaming in various drinks and assess ways of understanding the mechanisms involved in foam formation/stability as well as investigating options for controlling and, where required, enhancing foam.

Haze project update

One aspect of this research project is the assessment and development of methods for measuring and characterising hazes in beers with novel ingredients and other novel alcoholic beverages such as beer mixes, cider/fruit mixes and spirits with novel additives. Haze formation is a quality problem that can affect a wide range of drinks. Non-microbiological particles that can cause haze include starch, beta-glucan, proteins, lipids and crystalline substances.

Most research in this area has focussed on beer, for which some predictive models have been developed. However, with the emergence of many novel alcoholic drink types on the market, there is a need to also identify the factors influencing haze development in these new products. This would allow manufacturers to optimise beverage composition and processing as well as predict colloidal stability. Previously, we carried out a major study investigating haze development in beer. In all cases the presence of particles (either measured in terms of haze or sub-micron particles) in the fresh products influenced the development of haze. In this study we will establish whether the influential parameters contributing to this beer haze model - sub-micron particles, protein (including haze-active protein), chill/permanent haze - are also of importance in other alcoholic drinks. A number of other factors identified in the above review, such as pH, ethanol, sugars, polyphenols and oxygen, will also be assessed for their impact. These may not be as important for haze formation in beer but could well be the drivers for the new alcoholic beverages under study here. Natural haze development as well as forcing tests will be performed and any correlations between haze and the physicochemical parameters established. This will allow some new insights into haze formation in non-beer alcoholic beverage categories.

The product categories under review are: fruit cider, beer mix/Radler, flavoured beer and formulated spirit. The initial investigations have concentrated on red fruit ciders as there are a number of brands available and this market is still expanding. At present 18 different red fruit ciders (from the large well known companies to smaller independent firms) have been investigated.