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38 search results for: spectrophotometer

Greg Howell21

“Low preservative” wines – just how low is low?

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As part of a recent project to develop a new Test Kit for the determination of Sulfur Dioxide for use with Spectrophotometer and Discrete Analysers, we tested a batch of commercially purchased wines labelled “low preservative”, so we could be sure that the Test Kits worked across the full range of sulfur dioxide levels. To our surprise, a number of these wines were not low at all! This is of concern to our industry as some consumers are very interested in and aware of the preservative levels of the foods and drinks they purchase. Is it time for the wine industry to decide what the level of sulfur dioxide should be to qualify for a “low preservative” statement?

22

Enzymatic testing in the wine lab

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Enzymatic methods in the wine laboratory are incredibly accurate, fast and safe, helping to generate important information about your wine to ensure the most informed decisions are made. Whether the methods are performed on a benchtop spectrophotometer or an automatic analyzer, understanding the equipment and materials you are working with is essential to getting the right result the first time. Unfortunately, it doesn’t always go to plan, so it’s important to understand what can be causing poor results and how to fix it.

24

Natural Wines and Foaming Cider Kegs! – Testing Times July 18

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  Natural wine To quote wine writer Max Allen (1) “The hottest wine trend of the decade? That’s easy: all things natural. Grapes grown with a minimum of sprays, preferably organic or biodynamic; nothing added in the cellar except perhaps a small amount of sulphur dioxide preservative at bottling. Just wine. It’s also been the […]

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Fizzing Red and Tartrate Stabilisation – Testing Times – June 2017

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This month – Red Wine Fizzing and Tartrate Stabilisation with CMC Vintessential Laboratories are dedicated to helping our winery customers discover winemaking problems early, understand them, and then fix them. At our five laboratories around Australia we test hundreds of samples every week, so there’s hardly a problem we haven’t seen. Every month we bring you […]

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Interwinery Analysis Group finds best test for sugars in wine

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Carly Gamble and Greg Howell Introduction Determining the sugar content of juice and wine is an essential part of the winemaking process.  Glucose and fructose are the most abundant sugars naturally present in grapes and they are also fermentable sugars – their presence in finished wine leaving the wine susceptible to spoilage.  Accurate monitoring of […]

27

Tip: Troubleshooting enzymatic calibration curves

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With an increasing number of labs upgrading from benchtop spectrophotometers to automatic discrete analysers for their enzymatic testing, it is worth noting that the major difference between the two approaches (apart from speed!) is in the calculation of the sample results. A discrete analyser calculates a calibration curve from a series of known standard solutions. […]

28

Tip: A closer look at absorbance

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Absorbance readings taken from spectrophotometers during enzymatic analysis should be considered carefully before they are used to calculate important wine parameters. Many spectrophotometers have a photometric range up to about 3.0 absorbance, but this does not necessarily mean that any value up to 3.0 is an accurate reading. Spectrophotometers don’t directly measure absorbance, they actually […]

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A simple and easy way to organise your lab for vintage

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  Introduction Prior to your busy vintage period, it’s important to be as organized as possible in your laboratory. One way to do this is to generate 3 main lists of what you require to effectively run your lab – we show you how below. By having all the tests you do documented as Test […]

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Yeast nutrition and successful fermentations

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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 […]