Ask the AWRI

2018 Ask the AWRI


Lightstruck character (PDF) – reproduced with permission from Winetitles Media

Coulter, A. Lightstruck character. Australian & New Zealand Grapegrower & Winemaker (654) : 76-77; 2018.

Abstract: The AWRI sometimes receives enquiries regarding development of ‘lightstruck’ character in bottled wine during storage. This column provides a brief summary of this phenomenon.


Brown marmorated stink bug (PDF) – reproduced with permission from Winetitles Media

Longbottom, M. Brown marmorated stink bug. Australian & New Zealand Grapegrower & Winemaker (653) : p. 53; 2018.

Abstract: Brown marmorated stink bug (BMSB) is an exotic pest, known to cause damage to a range of crops in other countries. This year dead and alive brown marmorated stink bugs (BMSBs) were detected in Australia in several shipping containers from Italy. The Department of Agriculture and Water Resources implemented off-shore treatment measures between January and April to ensure that the risk of more live BMSBs arriving in Australia was minimised. While this pest is currently not established in Australia, it is one of Australia’s top 40 high priority plant pests. This column provides answers to common questions about this bug, and why it should be taken seriously as a threat to Australian viticulture.


Understanding whole-bunch fermentation (PDF) – reproduced with permission from Winetitles Media

Godden, P. Understanding whole-bunch fermentation. Australian & New Zealand Grapegrower & Winemaker (652) : p. 63; 2018.

Abstract: During the 2016 and 2017 vintages, the AWRI made small-lot Pinot Noir and Shiraz wines from single batches of fruit, demonstrating the effects of changing one winemaking variable at a time. During tastings of those wines presented across Australia, many winemakers asked why there are such large sensory differences between wines made with 100% pure carbonic maceration and those made with the more common whole-bunch fermentation treatment. A previous ‘Ask the AWRI’ discussed carbonic maceration, and this one examines whole-bunch fermentation.


Carbonic maceration (PDF) – reproduced with permission from Winetitles Media

Cowey, G. Carbonic maceration. Australian & New Zealand Grapegrower & Winemaker (651) : 70-71; 2018.

Abstract: During the 2016 and 2017 vintages, the AWRI made small-lot Pinot Noir and Shiraz wines from single batches of fruit, demonstrating the effects of changing one winemaking variable at a time. During tastings of these wines presented across Australia, many winemakers have asked why there are such large sensory differences between wines made with 100% pure carbonic maceration and those made with the more common semi-carbonic maceration treatment or whole bunch fermentation. This column explores what is happening during carbonic maceration.


Spray drift (PDF) – reproduced with permission from Winetitles Media

Essling, M. Spray drift. Australian & New Zealand Grapegrower & Winemaker (650) : 34-35; 2018.

Abstract: Damage to grapevines caused by herbicides drifting onto vineyards from sprays conducted on nearby properties occurs occasionally in Australia. Queries about this issue, commonly known as ‘spray drift’, are received from time to time by the AWRI helpdesk. This column provides answers to some of the more common questions about this topic.


Wine instabilities – the solids won’t hurt you (PDF) – reproduced with permission from Winetitles Media

Stockley, C. Wine instabilities – the solids won’t hurt you. Australian & New Zealand Grapegrower & Winemaker (649) : p. 66; 2018.

Abstract: A range of hazes and deposits can form in wine and these can sometimes cause concerns for consumers. The AWRI helpdesk has recently received queries asking if there are any health risks associated with consuming wines affected by hazes or deposits. This column discusses the common instabilities seen in wine and provides reassurance that they do not pose health or safety risks.


Volatile acidity (PDF) – reproduced with permission from Winetitles Media

Coulter, A. Volatile Acidity. Australian & New Zealand Grapegrower & Winemaker (648) : p. 16; 2018.

Abstract: Analysis of volatile acidity (VA) was probably the wine industry’s first measure of wine quality and is routinely used as an indicator of wine spoilage. This column looks at some of the questions AWRI helpdesk staff commonly receive about VA.


2017 Ask the AWRI


Biosecurity and viticulture (PDF) – reproduced with permission from Winetitles Media

Longbottom, M. Biosecurity and viticulture. Australian & New Zealand Grapegrower & Winemaker (647) : 44-45; 2017.

Abstract: Australia has a fortunate status as an island nation that is free of many pests and diseases found in other countries, but from time to time new issues are discovered. Most of these are not of major concern, but are nevertheless dealt with seriously to protect Australia’s valuable agricultural industries. This column presents answers to some common questions about Australia’s biosecurity management system.


Wine – a weighty issue (PDF) – reproduced with permission from Winetitles Media

Stockley, C. Wine – a weighty issue. Australian & New Zealand Grapegrower & Winemaker (646) : p. 44; 2017.

Abstract: The AWRI helpdesk often receives enquiries about the calorie content of wine and whether wine makes you ‘fat’. This column provides answers to some key questions about body weight and the consumption of alcoholic beverages.


Sooty mould (PDF) – reproduced with permission from Winetitles Media

Godden, P. Sooty mould. Australian & New Zealand Grapegrower & Winemaker (645) : 30-32; 2017.

Abstract: During the 2017 vintage, some wine-grape growers in several regions were severely affected by ‘sooty mould’. The thresholds for the presence of all moulds at which some wine producers downgrade or reject fruit is 3%, which means that there is potential for sooty mould to cause significant economic losses to grapegrowers. In addition, any effects of sooty mould on the composition and sensory qualities of wine are not well understood. This column provides answers to some common questions about sooty mould.


Vineyard snail control: exploring the options and the timing (PDF) – reproduced with permission from Winetitles Media

Essling, M. Vineyard snail control: exploring the options and the timing. Australian & New Zealand Grapegrower & Winemaker (643) : 46-47; 2017.

Abstract: Snails are a vineyard pest that can cause damage to buds and foliage, particularly during spring. This article provides answers to questions commonly raised with the AWRI helpdesk about controlling snails in vineyards.


The tricks and traps of deacidification (PDF) – reproduced with permission from Winetitles Media

Coulter, A. The tricks and traps of deacidification. Australian & New Zealand Grapegrower & Winemaker (642) : 56-57; 2017.

Abstract: The cooler than usual 2017 vintage resulted in some wines with higher titratable acidity (TA) levels than usual. In some cases, circumstances necessitated deacidification and winemakers contacted the helpdesk requesting advice. This column focuses on the chemical deacidification of wine using permitted carbonate salts.


Soil analysis and soil carbon: what should you be looking for when getting your soil tested? (PDF) – reproduced with permission from Winetitles Media

Longbottom, M. Soil analysis and soil carbon: what should you be looking for when getting your soil tested?. Australian & New Zealand Grapegrower & Winemaker (641) : 44-45; 2017.

Abstract: Soil sampling is a useful management tool that can be used prior to establishing a vineyard and also throughout the productive life of grapevines. Soil analysis can provide critical information about the key properties of soil, nutrient status, fertiliser requirements or to monitor the efficacy of soil amelioration, for example the addition of lime or gypsum.


Why was there more powdery mildew than usual this season? (PDF) – reproduced with permission from Winetitles Media

Essling, M. Why was there more powdery mildew than usual this season? Australian & New Zealand Grapegrower & Winemaker (640) : 30-31; 2017.

Abstract: Powdery mildew is caused by the fungus Erysiphe necator (formerly Uncinula necator). Unlike most fungi, the powdery mildew fungus relies on wet weather for only a small part of its lifecycle. It usually develops in dry conditions but spreads most extensively at high humidity in mild, cloudy weather, inside shaded canopies. One reason for this is that the fungus grows on the surface of infected foliage and is retarded by direct exposure to sunlight.


Adding water to high sugar must (PDF) – reproduced with permission from Winetitles Media

Cowey, G. Adding water to high sugar must. Australian & New Zealand Grapegrower & Winemaker (639) : 88-89; 2017.

Abstract: In February, an amendment was made to the Australia New Zealand Food Standards Code (FSC) to allow limited addition of water to high sugar must and juice to reduce the chance of fermentation problems. Previously water had not been allowed as a direct additive to grape juice, must or wine, with a maximum (cumulative) addition of 70 mL/L water allowable only for the incorporation of permitted additives or processing aids during the winemaking process.


Taints in wine (PDF) – reproduced with permission from Winetitles Media

Holdstock, M. Taints in wine. Australian & New Zealand Grapegrower & Winemaker (638) : p. 64; 2017.

Abstract: Each year the AWRI helpdesk investigates a range of taints in wines. In some of these cases, the taints cannot be remediated, and the wine is left unsaleable. It is therefore important to understand the more common sources of taints and take steps to avoid them. Some of the more frequent questions asked about taints are answered below.


Assessing and managing disease levels close to harvest (PDF) – reproduced with permission from Winetitles Media

Petrie, P. Assessing and managing disease levels close to harvest. Australian & New Zealand Grapegrower & Winemaker (637) : 32-33; 2017.

Abstract: This article looks at how to manage disease-affected grapes close to harvest.


Understanding molecular SO2 (PDF) – reproduced with permission from Winetitles Media

Coulter, A. Understanding molecular SO2. Australian & New Zealand Grapegrower & Winemaker (636) : p. 76; 2017.

Abstract: Sulfur dioxide (SO2) is a key preservative used in winemaking, but how it works in wine is quite complicated. Concentrations of SO2 required to prevent microbial growth are often quoted as molecular SO2, but winemakers can be more familiar with discussing free and total SO2. This column brings together answers to some of the more common questions about the different forms of SO2 in wine, how much is needed and which factors can change its effectiveness.


2016 Ask the AWRI


Grapevine tissue analysis (PDF) – reproduced with permission from Winetitles Media

Longbottom, M. Grapevine tissue analysis. Australian & New Zealand Grapegrower & Winemaker (635) : 36-37; 2016.

Abstract: Grapevine tissue analysis can provide critical information about vine nutrient status to assist with fertiliser decisions, problem diagnosis and monitoring the impacts of management practices. This article provides answers to some of the most common questions on this topic.


Wine consumption and brain health (PDF) – reproduced with permission from Winetitles Media

Stockley, C.S. Wine consumption and brain health. Australian & New Zealand Grapegrower & Winemaker (634) : p. 82; 2016.

Abstract: Research has recently been conducted on the effects of alcohol (and specifically wine) consumption on brain function, such as cognition and the risk of dementia. This article provides responses to some of the more common questions in this area.


Re-entry periods after vineyard sprays (PDF) – reproduced with permission from Winetitles Media

Essling, M. Re-entry periods after vineyard sprays. Australian & New Zealand Grapegrower & Winemaker (633) : p. 54; 2016.

Abstract: The 2016/2017 edition of Agrochemicals registered for use in Australian viticulture (also known as the ‘Dog Book’) for the first time features guidelines about re-entry into vineyards after agrochemicals have been applied. This column summarises some common questions about vineyard re-entry periods.


Calcium and its unpredictable presence (PDF) – reproduced with permission from Winetitles Media

Holdstock, M. Calcium and its unpredictable presence. Australian & New Zealand Grapegrower & Winemaker (632) : 68-69; 2016.

Abstract: Earlier in the year this column featured KHT deposits and cold stability. This month the focus is shifting to calcium instabilities, another type of deposit seen quite commonly by the AWRI helpdesk.


Not so pretty in pink (PDF) – reproduced with permission from Winetitles Media

Cowey, G. Not so pretty in pink. Australian & New Zealand Grapegrower & Winemaker (631) : p. 86; 2016.

Abstract: Pinking is a term used to describe the sudden and unexpected development of a salmon/bronze colour in white wines after bottling or when poured into a glass. Although the aroma and flavour of the wine generally remain unchanged, the pink colour often can be misconstrued as the brown colour more typically associated with wine oxidation. This appearance can subconsciously influence the consumers’ expectation of the taste of wine, with pink wines often considered oxidised. This article explains pinking and looks at its treatment and prevention.


Help! What cultivar (or clone) is this? (PDF) – reproduced with permission from Winetitles Media

Petrie, P. Help! What cultivar (or clone) is this? Australian & New Zealand Grapegrower & Winemaker (630) : 40-41; 2016.

Abstract: While growers and winemakers generally know which grape cultivars they are growing or making into wine, there are a range of scenarios where it is important to be able to definitively identify a rootstock or scion. Accurate cultivar identification is essential for nursery operators as part of their quality assurance programs.


KHT deposits and cold stability (PDF) – reproduced with permission from Winetitles Media

Coulter, A. KHT deposits and cold stability. Australian & New Zealand Grapegrower & Winemaker (629) : p. 76; 2016.

Abstract: Potassium bitartrate (KHT) is the crystalline substance that drops out of solution when a wine is cold stabilised. However, if cold stabilisation is unsuccessful, wines can end up with KHT deposits after packaging and these represent around 25–35% of the AWRI helpdesk’s haze/deposit investigations each year. So why does this type of deposit continue to be an issue for the wine industry? The article addresses the following questions:

  • So what exactly is ‘cold stability’?
  • Which wine parameters affect ‘cold stability’?
  • Why does wine pH sometimes change during cold stabilisation?
  • What does the saturation temperature value for a wine mean?
  • Which ‘cold stability’ test does the AWRI recommend?

Grazing sheep in vineyards (PDF) – reproduced with permission from Winetitles Media

Essling, M. Grazing sheep in vineyards. Australian & New Zealand Grapegrower & Winemaker (628) : 46-47; 2016.

Abstract: It is becoming more common to see sheep grazing in Australian vineyards between late autumn and spring. This article addresses the most common questions asked by vineyard owners about this practice.

  • What are the benefits of grazing sheep in a vineyard?
  • When is the best time to graze sheep in the vineyard and how many should there be?
  • What savings can be expected in terms of operating costs and GHG emissions?
  • Is infrastructure needed?
  • Do agrochemical residues need to be considered?
  • Will the sheep cause damage in the vineyard?
  • Can any other types of animals be used in vineyards?

Health and nutrition labelling (PDF) – reproduced with permission from Winetitles Media

Stockley, C.S. Health and nutrition labelling. Australian & New Zealand Grapegrower & Winemaker (627) : p. 66; 2016.

Abstract: The AWRI helpdesk regularly receives questions about health and nutrition labelling for wine and wine products. Broadly the questions can be divided into the areas of alcohol, allergens, preservatives and health and nutrition statements, which all fall under the auspices of the Australia and New Zealand Food Standards Code. This article addresses some of the most common questions as outlined below.

  • How do I express alcohol content?
  • Which allergens do I need to label for?
  • Do I need to label for preservatives?
  • How do I calculate standard drinks?
  • Am I permitted to make health and nutrition statements?
  • What are the rules for cleanskins?

Predicting alcohol levels (PDF) – reproduced with permission from Winetitles Media

Cowey, G. Predicting alcohol levels. Australian & New Zealand Grapegrower & Winemaker (626) : p. 68; 2016.

Abstract: Over the past two vintages winemakers have been reporting higher than normal conversions of sugar to alcohol. One example was a must measured at 13.5 Baume that ended up with a 15% v/v alcohol concentration. Estimating potential alcohols based on grape must analysis is not as straightforward as many winemakers assume. This article addresses some key points to be taken into account.


Measuring canopy size (PDF) – reproduced with permission from Winetitles Media

Petrie, P. Measuring canopy size. Australian & New Zealand Grapegrower & Winemaker (625) : 36-37; 2016.

Abstract: Canopy size and density are important viticultural measures that relate to fruit quality. Traditionally, however, they have been difficult to measure. The University of Adelaide has recently released an app that allows growers to assess grapevine canopies using an iPhone or iPad. Some common questions about using the app are addressed in this article.


All things analysis (PDF) – reproduced with permission from Winetitles Media

Holdstock, M. All things analysis. Australian & New Zealand Grapegrower & Winemaker (624) : 52-53; 2016.

Abstract: Each year the AWRI helpdesk answers a number of enquiries about wine analysis including how to interpret a result or how to troubleshoot a laboratory issue. The questions and answers in this article represent some frequent and some more obscure questions received in the recent past.


2015 Ask the AWRI


Skipping vineyard sprays in dry year (PDF) – reproduced with permission from Winetitles Media

Essling, M. Skipping vineyard sprays in dry year. Australian & New Zealand Grapegrower & Winemaker (623) : p. 38; 2015.

Abstract: The articles looks at strategies to control powdery mildew, downy mildew and botrytis during dry years.


Spoilage due to lactic acid bacteria (PDF) – reproduced with permission from Winetitles Media

Coulter, A. Spoilage due to lactic acid bacteria. Australian & New Zealand Grapegrower & Winemaker (622) : 76-77; 2015.

Abstract: Lactic acid bacteria (LAB) are the microorganisms that conduct malolactic fermentation (MLF) in winemaking, but they can also cause wine spoilage. Some of the more common questions about LAB spoilage are discussed in this issue.


Nitrous oxide and viticulture (PDF) – reproduced with permission from Winetitles Media

Longbottom, M. Nitrous oxide and viticulture. Australian & New Zealand Grapegrower & Winemaker (621) : 42-43; 2015.

Abstract: Nitrous oxide (N2O) is one of the main greenhouse gases (GHGs) contributing to climate change. Over the past three years the AWRI has been working on a project to collect data on N2O emissions from vineyards across Australia and to investigate the effects of different vineyard floor management practices on N2O production.


DIY haze and deposit identification (PDF) – reproduced with permission from Winetitles Media

Cowey, G. DIY haze and deposit identification. Australian & New Zealand Grapegrower & Winemaker (620) : p. 87; 2015.

Abstract: A high proportion of questions answered and investigations conducted by the AWRI helpdesk are related to hazes and deposits in wine. While the helpdesk is well equipped to identify both common and unusual hazes and deposits, there are some steps that can be taken in the winery lab or kitchen to achieve a quick DIY identification.


Wine consumption and heart health (PDF) – reproduced with permission from Winetitles Media

Stockley, C. Wine consumption and heart health. Australian & New Zealand Grapegrower & Winemaker (619) : p. 72; 2015.

Abstract: A large amount of research has been conducted on the effects of alcohol (and specifically wine) consumption on the risk of cardiovascular disease. This column provides responses to some of the more common questions in this area.


Bunch stem necrosis (PDF) – reproduced with permission from Winetitles Media

Petrie, P. Bunch stem necrosis. Australian & New Zealand Grapegrower & Winemaker (618) : p. 36; 2015.

Abstract: Last season saw a spike in queries to the AWRI helpdesk about bunch stem necrosis (BSN), with incidence across most Australian regions. While the causes of BSN are not fully understood, this column summarises current knowledge about this disorder.


Trouble-free packaging (PDF) – reproduced with permission from Winetitles Media

Holdstock, M. Trouble-free packaging. Australian & New Zealand Grapegrower & Winemaker (617) : p. 92; 2015.

Abstract: The AWRI helpdesk team often receives questions about packaging and avoiding problems when wine goes from tank to bottle and beyond. Some of the more common ones are outlined below. How much SO2 is lost during packaging? I need to add some last minute copper sulfate to my wine, should I push my bottling date back? Do I need to cold stabilise again if I’m sweetening my wine up with grape juice concentrate just before bottling? After my wine was bottled with natural cork closures the bottles were left upright instead of inverted, is this standard practice? My empty glass bottles have been stored outside for a long time, is it still OK to use these? How useful is filterability testing prior to bottling?


Unmanned aerial vehicles (drones) and viticulture (PDF) – reproduced with permission from Winetitles Media

Petrie, P. Unmanned aerial vehicles (drones) and viticulture. Australian & New Zealand Grapegrower & Winemaker (616) : p. 47; 2015.

Abstract: Drones can be used to provide information about vineyards such as assessing for frost damage, water stress and missing vines or creating vigour maps.


Copper: friend or foe? (PDF) – reproduced with permission from Winetitles Media

Coulter, A. Copper: friend or foe? Australian & New Zealand Grapegrower & Winemaker (615) : p. 73; 2015.

Abstract: Copper instabilities are one of the most common metal instabilities, mainly because of the low concentrations required to cause instability. Copper is also a catalyst for oxidation and reduction reactions and again, low concentrations can have an impact. Furthermore, copper reacts with thiols, so it can affect the varietal aromas of wines, especially those where thiols play a major role, such as Sauvignon Blanc and Cabernet Sauvignon.


Rainfall close to harvest (PDF) – reproduced with permission from Winetitles Media

Essling, M. Rainfall close to harvest. Australian & New Zealand Grapegrower & Winemaker (614) : p. 32; 2015.

Abstract: Heavy rain in the four-to-six weeks before harvest is always a risk to grape yield and quality. The ripening berry becomes increasingly susceptible to bunch rots as sugar level increases and fruit softens. High humidity and cloudy conditions provide ideal conditions for powdery mildew, but it is the bunch rots that are usually the most difficult to control.


Avoid mousy, off-flavours (PDF) – reproduced with permission from Winetitles Media

Cowey, G. Avoid mousy, off-flavours. Australian & New Zealand Grapegrower & Winemaker (613) : p. 50; 2015.

Abstract: Many winemakers are experimenting with new techniques in white winemaking such as high grape solids ferments, extended lees ageing, higher pH with minimal sulfur dioxide (SO2), oxidative ageing and minimal clarification or filtration. In many cases the aim of these practices is to produce white wines with more texture. While these changing practices have resulted in some great successes, they also come with some increased risks. The incidence of both ‘Brett’ and mousy characters in white wines submitted to the AWRI helpdesk is on the rise. Common questions about mousy off-flavour are explored below.


Effects of hot and dry conditions (PDF) – reproduced with permission from Winetitles Media

Longbottom, M. Effects of hot and dry conditions. Australian & New Zealand Grapegrower & Winemaker (612) : p. 38; 2015.

Abstract: Hot and dry conditions have been experienced across many Australian wine regions in recent years, resulting in a number of questions to the AWRI helpdesk.


2014 Ask the AWRI


The power of pH (PDF) – reproduced with permission from Winetitles Media

Holdstock, M. The power of pH. Australian & New Zealand Grapegrower & Winemaker (611) : p. 72; 2014.

Abstract: A previous ‘Ask the AWRI’ column looked at acidity and answered the most common questions received about this parameter. This column considers the other equally, if not more, important partner – wine pH. Some winemakers believe this is the single most important analytical parameter to measure when making wine (closely followed by SO2).


Questions about drink driving (PDF) – reproduced with permission from Winetitles Media

Stockley, C.S. Questions about drink driving. Australian & New Zealand Grapegrower & Winemaker (610) : p. 66; 2014.

Abstract: Consumers and winemakers often ask questions about how their driving is affected when they drink a glass or two of wine. Why isn’t it safe to drink and drive? Like most countries, Australia has strict laws about drinking alcohol and driving. Across all states and territories, the legal limit for fully licensed drivers has been set at 0.05 blood alcohol concentration (BAC), which equates to 0.05 g of alcohol in a person’s body for every 100 mL of blood. This is the level above which the risk of being involved in a crash increases significantly. When behind the wheel of a vehicle, drivers need total concentration, good coordination, rapid reflexes and the ability to make correct judgements and decisions.


Export focus on residual metals (PDF) – reproduced with permission from Winetitles Media

Stockley, C.S. Export focus on residual metals. Australian & New Zealand Grapegrower & Winemaker (609) : p. 80; 2014.

Abstract: In March 2014, Wine Australia issued a warning to wine exporters regarding increased scrutiny of manganese, iron and copper levels in wine by Chinese authorities. Since then, the AWRI helpdesk has received a number of queries from grapegrowers and winemakers concerned about manganese in grapes and wine.


Acidity in all its various aspects (PDF) – reproduced with permission from Winetitles Media

Coulter, A.D. Acidity in all its various aspects. Australian & New Zealand Grapegrower & Winemaker (608) : p. 88; 2014.

Abstract: The AWRI often receives queries relating to various aspects of acidity. Given the importance of pH to the stability and development of wine and the importance of titratable acidity (TA) to wine’s sensory properties, this article answers some of the more common acidity-related questions.


Viticulture and greenhouse gas emissions (PDF) – reproduced with permission from Winetitles Media

Longbottom, M. Viticulture and greenhouse gas emissions. Australian & New Zealand Grapegrower & Winemaker (607) : p. 54; 2014.

Abstract: Grapegrowers across Australia are already feeling the impact of a changing climate with earlier budburst, shorter winters, compressed vintages and more frequent extreme weather events such as frosts, heat waves and bushfires. Questions and answers about greenhouse gases and climate change as they relate to viticulture are outlined below.


The ABCs of filtration and what works for you (PDF) – reproduced with permission from Winetitles Media

Cowey,G. The ABCs of filtration and what works for you. Australian & New Zealand Grapegrower & Winemaker (606) : p. 60; 2014.

Abstract: This article answers some of the more common questions about filtration including: What is the difference between absolute and nominal filter ratings? What is the difference between depth and surface filtration? Can I use cross flow for sterile filtration? What NTU level do I need for filtration? What level of filtration do I need? Does filtration strip out colour and flavour?


Can you achieve yield control in the vineyard without using bunch thinning? (PDF) – reproduced with permission from Winetitles Media

Dry, P. Can you achieve yield control in the vineyard without using bunch thinning? Australian & New Zealand Grapegrower & Winemaker (605) : p. 40; 2014.

Abstract: This articles looks at alternative yield control methods like early leaf removal in the bunch zone and the application of an anti- transpirant spray to the whole canopy from the time of flowering.


Here’s the hot topics of vintage 2014 (PDF) – reproduced with permission from Winetitles Media

Holdstock, M. Here’s the hot topics of vintage 2014. Australian & New Zealand Grapegrower & Winemaker (604) : p. 79; 2014.

Abstract: The AWRI helpdesk has received more than 420 winemaking-related queries so far during the 2014 vintage. This article presents a snapshot of some of the ‘hot topics’ of 2014. The most frequent query topic to date has been smoke taint. It has been by far the biggest challenge of 2014, representing nearly 25 per cent of all calls received by the AWRI’s helpdesk during the early stages of vintage.


Bunches with ripe and unripe berries (PDF) – reproduced with permission from Winetitles Media

Dry, P. Bunches with ripe and unripe berries. Australian & New Zealand Grapegrower & Winemaker (603) : p. 49; 2014.

Abstract: This article presents the observations of the late Dr Bryan Coombe regarding the ‘sweet and sour’ disorder which Dr Coombe documented during 1999/2000 growing season.


Can ‘Brett’ affect white wines? (PDF) – reproduced with permission from Winetitles Media

Coulter, A. Can ‘Brett’ affect white wines? Australian & New Zealand Grapegrower & Winemaker (602) : p. 54; 2014.

Abstract: It is well known that Brett spoilage can occur in red wines, however, can Brett spoilage also occur in white wines? The short answer is “yes”. The first case of Brett spoilage in a white wine investigated by the AWRI was in 2000, and there have been occasional cases investigated since then. However, an unusual trend has occurred recently with six cases of Brett in white wine investigated in the past six months. The level of 4-ethylphenol (4-EP), responsible for the Band-aid® aroma associated with Brett growth, ranged from 77 to 1320 ?g/L in these wines.


Canopy damage from herbicides? (PDF) – reproduced with permission from Winetitles Media

Essling, M. Canopy damage from herbicides Australian & New Zealand Grapegrower & Winemaker (601) : p. 32; 2014.

Abstract: The AWRI’s viticulture team received a query at the start of flowering from a grower concerned about canopy damage observed in their vineyard. The description of the damage and the photographs provided pointed to herbicides as the likely cause of the problem.


Top tips for a successful yeast culture (PDF) – reproduced with permission from Winetitles Media

Cowey, G. Top tips for a successful yeast culture. Australian & New Zealand Grapegrower & Winemaker (600) : p. 42; 2014.

Abstract: This article answers some common questions received at the AWRI about yeast and provides some top tips for yeast rehydration.