Introduction Sparkling wine is a bit of a strange substance to work with in a laboratory as it contains those pesky bubbles. Of course the bubbles are why we call it sparkling wine. But what exactly do we mean by ‘sparkling wine’? Sparkling wine – the Australian definition The definition actually varies from country to […]
Introduction There are numerous reasons why the use of traditional packaging for wine is changing. These can be for quality, environmental, cost or marketing reasons. Changing the form of the packaging can involve a number of technical challenges and problems, as the recent trend to screwcap bottles has demonstrated. In this article we look at […]
Introduction Successful primary fermentations of grape juice depend upon a number of factors: nutritional aspects are of critical interest as more becomes known about the nutritional needs of yeast. The following article discusses some of the relevant issues in regard to yeast nutrition in fermentations. Nutrients A number of different nutrient types are necessary for […]
Introduction There are a number of products made from Inactive Dry Yeast (IDY) that are used in various ways in modern winemaking. Many claims are made about their properties and benefits, however not all these claims have been scientifically proven leading to some confusion amongst winemakers. This article looks at the proven benefits of these […]
Introduction There are a number of different tests that are done on juice and must at the time of crushing and pressing. These tests are explained below with some new developments in tests and equipment noted. Testing during crushing and pressing The main analyses performed during the process of crushing and pressing grapes are well […]
Introduction Mannoproteins are a naturally occurring group of proteins found in the cell walls of yeasts. In particular, the mannoproteins in the wine yeast Saccharomyces cerevisiae have been studied extensively. The beneficial winemaking properties of mannoproteins, including tartrate stabilisation, are discussed in this article. Properties of mannoproteins It has been observed for many years that […]
Introduction Laboratory testing for a winery usually is thought of as dealing only with wine, but there is another important liquid that should be tested regularly – your drinking water. If your winery is not on “town water”, that is if you use tank water for drinking water then you may be risking the health […]
June 2013 Introduction The accurate measurement of alcohol in wine is relatively easy for experienced laboratory operators with the correct equipment and techniques. The use of this measurement on labels, however, is a regulatory minefield. In this article we discuss the best technique to measure alcohol and the best way to use the data correctly. […]
January 2013 Introduction Yeasts have a strict need for nitrogenous compounds during fermentation of grape juice. Most grape must is deficient in nitrogen and so supplements are normally added to increase the level of nitrogen compounds in the must. By having a sufficient level of nitrogen, the yeast can ferment the must to dryness with […]
Introduction The following is a written version of a presentation by the author to a meeting of the Interwinery Analysis Group in Adelaide on 26 July 2013. Botrytis cinerea – What is it? Botrytis cinerea is a common mould that occurs on many fruits. If you have ever seen strawberries with a grey fuzzy mould […]