Articles
Yeast nutrition and successful fermentations
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 […]
Yeast based wine additives – Are the many claims made about these products justified?
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 […]
Wine analysis during crushing and pressing
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 […]
Mannoproteins – How are they used in winemaking?
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 […]
Is the drinking water at your winery safe to drink?
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 […]
Alcohol and Standard Drinks Statements
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. […]
Nitrogen compounds and supplements
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 […]
New developments in Botrytis cinerea testing
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 […]
Survey of Yeast Assimilable Nitrogen Status in Chardonnay and Shiraz Grapes from the Granite Belt 2012 Vintage
Yeast Assimilable Nitrogen (YAN) is necessary for yeast growth and fermentation activity in grape must. It is comprised of two major components, amino acid nitrogen (AAN) and ammonia nitrogen (AN). Maintaining an adequate supply of YAN is essential for a successful fermentation, as both deficiency and excess of nitrogen can cause problems. Low YAN […]
Take care of your pH electrode!
Measuring pH is one of the most important tests in the winery but it can also be one of the most frustrating. A sluggish or non-reproducible response indicates that the pH reading may not be accurate. Can you trust the equipment you’re using? Taking a few simple steps to look after the electrode each time […]
Post Fermentation spoilage compound analysis
With harvest coming to an end in most regions of Australia, many of you will be happy to put the challenges of this growing season behind you! Primary and secondary fermentations are now in full swing which brings a new set of challenges, such as producing wines without excessive levels of spoilage compounds. Three compounds […]
Product recommendation March 2012 – Anchor NT50
Anchor NT50: A yeast for producing fruity red wines NT 50 enhances red berries (strawberry, raspberry and cherry), black berries (blackberry and black currant) and spicy aromas in red wines. It is suitable for wine with or without wood maturation. It is most suited for vinifying Shiraz, Grenache, Pinot Noir, Gamay, Cabernet Franc and Zinfandel. […]
Anchor NT202 Co-inoculant bacteria
The team at Anchor Yeast have had published an article in the March 2012 issue of Grapegrower and Winemaker magazine on the newly released NT202 Co-inoculant bacteria. The conclusion was that Anchor NT 202 Co-Inoculant when used with Anchor Yeast NT 202 ensure a simple, secure and speedy AF and MLF. Advantages over inoculation after […]
Measuring Yeast Assimilable Nitrogen (YAN)
Maintaining an adequate supply of nitrogen is essential for a successful fermentation, as both deficiency and excess of nitrogen can cause problems. Increased production of hydrogen sulphide is associated with low nitrogen availability, which can then lead to sluggish or stuck ferments. Conversely, excess nitrogen present at the completion of fermentation can be used by […]
Vintage Woes
Introduction Another vintage and the usual suspect samples, and more, arrived in our laboratories. The main feature of this vintage that will be remembered is the highest atmospheric temperatures ever recorded in Southern Australia. The temperatures in the high 40s on the Celsius scale that were experienced in February affected fruit throughout South East Australia […]
All you ever wanted to know about wine tannins but were too afraid to ask
Introduction The topic of tannins is about to come up at the Annual ASVO Oenology seminar on October 6th in Adelaide. To try and prepare those attending the seminar, the following article discusses some basic concepts about tannins and their application in wine. It’s difficult to discuss tannins without getting into some serious chemistry; so […]
Smoke taint in Winegrapes from the Victorian Bushfires of 2009
Introduction In the May 2007 issue of Grapegrower and Winemaker we discussed the impact of smoke from bushfires in the North East and Eastern regions of Victoria on grapes grown in these and surrounding regions (1). This current vintage has seen an unprecedented incidence of bushfires in Victoria, in several cases involving vineyards being burnt. […]
Preparing your winery laboratory for vintage
Introduction There are a number of things to consider in preparing your wine lab for vintage. The major areas of laboratory equipment and the consumables needed to run them, the calibrations of the equipment and the standardisation of the consumable solutions are discussed below. The membership of proficiency programs is also promoted as a way […]
Malolactic Fermentation Monitoring
Introduction Accurate monitoring of Malolactic fermentation (MLF) is one of the most critical analytical parameters in red winemaking, but one that is commonly overlooked prior to bottling. We are often asked to investigate causes of red wine spoilage, and one of the first questions we ask the winemaker is “what was the malic acid concentration […]
Successful Malolactic Fermentations
Introduction Malolactic fermentation (MLF) can be one of the most problematic areas that a winemaker has to manage. The advent of commercial preparations of bacterial cultures for MLF has both simplified and improved this difficult area. Research is ongoing on MLF and the results of this work is helping to further improve these preparations and […]
