Friday, 11 June 2021 05:22

Vine to Wine: A Year of Viti/Vini - June

Written by Nova Cadamatre MW

June is a time of great change in the vineyard.  At the beginning of the month, the vines have short shoots with berries that have just set. By the end of the month, the shoots are almost fully grown and have discernable clusters.  This is a period of rapid cell division for the berries. With regard to the clusters, the number of individual cells within each berry increases in preparation for the next phase of cell expansion (to be covered in July) when the final berry size is largely determined.

Once green shoots and leaves begin to form in the spring, fungal diseases immediately become a cause for concern. Maritime climates, in proximity to the coast, are typically humid. Continental climates, although well away from the coast and its moisture, can be impacted by lakes and rivers. Additionally, both climates receive precipitation during the summer which increases the risk of fungal disease. Even Mediterranean climates, which are hallmarked by a dry growing season as a rule, can be humid, especially if the winter rains continued into spring.  

The fungal diseases that are of most concern to the wine grower are powdery mildew, downy mildew, and botrytis.  

Climate Types 

An oceanic/maritime climate is characterized by narrow diurnal (daily) temperature swings, a narrow annual temperature range, temperate summers and cool winters. Rain is plentiful and falls evenly throughout the year; storms are frequent, as is cloud cover. There are few temperature extremes in either direction.   

A Mediterranean climate is characterized by hot, dry summers and cool wet winters; however, the seasonal temperature differential is less disparate than is found in continental climates. There is no transitional spring and autumn period; the Mediterranean climate has only two seasons. Rainfall is light to moderate and mostly falls around the periods of equinox and throughout the winter. During the summer months, diurnal temperature swings are moderate near the coast but significantly increase further inland due to rapid heating from the sun and equally rapid cooling at dusk. 

A continental climate has warm summers and cold winters with large diurnal and annual temperature variations. Heat spikes and winter freezes are common. Precipitation is moderate. Marginally more rain falls during the warm months rather than the cold months, some in the form of violent thunderstorms. Winter precipitation often arrives as snow.

Excerpted from the French Wine Scholar manual

Powdery mildew, also known as Oidium, generally impacts grapevine leaves but in severe cases can attack the stems and clusters also.  It appears as a yellow patch on the leaves at first, then morphs to a light grey or white patch on the top and underside of the leaves often mimicking a dusting of white powder (hence its name).  Powdery mildew can be found in all climates where grapes are grown.  Sulfur sprays are a common treatment.

Downy Mildew
Downy Mildew

Downy mildew needs humidity to thrive so it is generally only found in areas where there is spring and summer rainfall.  It also begins on leaves as a yellow, oily-looking patch. If conditions are right, these patches morph into a fuzzy fungal growth on the underside of the leaf (hence its name).  

Powdery Mildew
Powdery Mildew

Both powdery and downy mildew impact the vine’s ability to photosynthesize and in severe cases can impact cluster development. Copper-containing sprays can be helpful in controlling downy mildew however since copper can build up to toxic levels in the soil with frequent use, it is important to monitor the amount of copper being used.

Botrytis largely attacks the grape cluster, and unlike the other two mildews discussed, is not always a negative occurrence.  It can be found in two forms; noble rot and grey rot.  Noble rot is the desirable version and appears when cool, moist mornings are followed by warm, dry afternoons.  This fungus is key to sweet wines such as Sauternes, Tokaji, and Trockenbeerenauslese.  It naturally dehydrates the ripe grape berries and concentrates flavors and acids to create an intensely complex and concentrated wine.  Grey rot (or sour rot) results when cool, moist mornings are followed by cool, moist/wet afternoons.  Grey rot is never a good thing and can cause severe damage and quality degradation of the fruit.  

The Impact of Noble Rot on the Berry 

Botrytis will reduce the grape’s total sugar content by 1/3 and drop tartaric acid and malic acid by 5/6s and 1/3 respectively. The overall result is an increase in total extract due to the diminishing proportion of liquid to solids; the berry’s water content is reduced to half. In addition, the mold produces gluconic acid which imparts a honeyed character to the wines made from botyrized fruit.

Excerpted from the French Wine Scholar manual

Proper vineyard set up can go a long way toward maximizing the quality of a site and the ease in which it can be managed.  It can be key in assisting the vineyard management team with controlling fungal diseases.  Ensuring that wind can travel easily through the canopy and around the clusters is a way to help manage disease pressure.  Choice of rootstock can also help negate soil borne dangers such as phylloxera or nematodes.  Also training and trellis design is key to making the most out of a vineyard’s potential.  One must always keep in mind the vine’s natural growth habit during training and either work with or in some cases against it to achieve a particular goal.  In nature, vines climb trees and it is only once the vine is established at the top of a tree and exposed to the sun that it will start to produce fruit.  

Sun exposure on the buds is what initiates the development of clusters so it is essential to manage this aspect of the vineyard to ensure consistent crops from year to year.  One example of a training system that works against the vine’s natural habits is the Scott-Henry system.  This is typically used on very vigorous sites with V. vinifera since this species generally has an upright growth habit.  (Vitis vinifera is the European grape species and is the most common used for high quality wine production) 

The bottom half of the Scott-Henry trellis is used to force some of the shoots to grow downward which the vine is not naturally inclined to do.  This causes the vines to spend considerable energy trying to grow upward thus reducing the vigor of the vine overall and bringing more vigorous sites into better balance.  

In the winery, wines are in their final preparatory steps for bottling. This typically involves filtration.  Filtration is the process by which suspended solids, yeast and bacteria are removed from the wine.  Filtration also removes the settled fining agents, as well as tartrate crystals which have precipitated out of solution during stabilization.  This step is particularly important for wines which have residual sugar. If yeast cells are allowed to remain in contact with sugar post-bottling, there is a danger of a second fermentation in the bottle. This creates a safety hazard for the consumer due to the pressure building up from carbon dioxide, a by-product of the fermentation process.

Next month, we will continue our exploration into the vineyard season by discussing the cell expansion phase, leaf pulling and its purpose, plus the effects of heat and wind in the vineyard.  In the winery, we will cover blending and bottling as well as barrel management. 


“Vine to Wine” is a new blog series that chronicles what is happening in the vineyard and in the winery each and every month of the calendar year. Nova Cadamatre, MW and winemaker, will author these authoritative and detailed posts drawing upon her studies (Cornell Viticulture and Enology graduate) as well as her winemaking experience in California, China and the Finger Lakes.

Each “Vine to Wine” installment details that month’s vineyard and winery tasks with deep dives into a particular grape growing or wine making topic such as pruning methods and training systems or barrel aging and fermentation vessels.

The series is designed to give wine students and educators an opportunity to develop or hone their technical savvy.

Want to know when new blog articles are released? Join this list to be notified! 

Want to know when new blog articles are released?
Join this list to be notified!

Study Viticulture and Winemaking on WSG Studio

Beyond the Basics: Reduction and Oxidation
With Nova Cadamatre MW
Meeting of the Minds: Heroic Viticulture
With Andrew Jefford, Caro Maurer MW, Paul Symington
Where to Put the Wine? An Exploration into Winemaking Vessels
With Nova Cadamatre MW
Climate, Grapes and Wine: Sustainability in a Variable and Changing Climate with Greg Jones, PhD
With Greg Jones, PhD
Beyond the Basics: Yeast and Fermentation with Olivier Humbrecht MW
With Olivier Humbrecht MW
Demystifying Winemaking : Part 3: Everything Else You Wanted to Know but Were Afraid to Ask! with Nova Cadamatre
With Nova Cadamatre MW
Sulphites in Wine with Simon J. Woolf
With Simon J. Woolf
Why Sustainability Certification Matters - A Winery’s Commitment to Environmental Stewardship with Martin Reyes, MW
With Martin Reyes MW
Meeting of the Minds: Climate Change
With Andrew Jefford, Dr. Greg Jones, Josep Maria Ribas Portella, Michelle Bouffard
Beyond the Basics: Wine Tannins with Vincenzo Gerbi and Maria Alessandra Paissoni
With Maria Alessandra Paissoni
Demystifying Winemaking: Part 2 - Reds with Nova Cadamatre, MW
With Nova Cadamatre MW
Demystifying Winemaking : Part 1 - White and Roses with Nova Cadamatre MW
With Nova Cadamatre MW
What Are Varietal Thiols And How Are They Expressed In Red Wine? with Marco Li Calzi, PhD
With Marco Li Calzi PhD
Meeting of the Minds: Evolution in Wine-Making Aesthetics and Wine-Making Trends
With Alberto Antonini, Andrew Jefford, Fiona Morrison MW, Pedro Ballesteros MW, Rosemary Cakebread
Why Altitude And Genetic Diversity Will Save Wine with Dr Laura Catena
With Dr. Laura Catena
The Myths of Terroir with Dr. Kevin R. Pogue
With Dr. Kevin R. Pogue
The Grafted Grapevine Part III: Rootstocks, a solution for climate change?
With Thomas Dormegnies
It's the Nitrogen, of course! The Backstory of Biodynamics with Romana Echensperger, MW
With Romana Echensperger MW
The Grafted Grapevine  Part II: How to Maintain Diversity?
With Thomas Dormegnies
You, Me, and VSP: Exploring the Difference Between Training and Trellising Methods with Nova Cadamatre, MW
With Nova Cadamatre MW
The Grafted Grapevine Part I: How to Produce a Grafted Grapevine?
With Thomas Dormegnies
Introduction to Geology, Soil, and Terroir with Brenna Quigley
With Brenna Quigley
Have Your Say: Natural Wine with Andrew Jefford and Simon J. Woolf
With Andrew Jefford, Simon J. Woolf
Natural wine - exploding the myths with Simon J Woolf
With Simon J. Woolf
From the Ground Up: Grapevine Anatomy 101 with Nova Cadamatre MW
With Nova Cadamatre MW
Heroic Viticulture: Europe's Most Dramatic Vineyards with Tanya Morning Star
With Tanya Morning Star
Rosé: Up Close and Technical with Elizabeth Gabay MW
With Elizabeth Gabay MW
Fortified Wines from Around the World with Guilherme Marques Martins, PhD
With Guilherme Marques Martins
The World of French Fortified Wines with Guilherme Marques Martins, PhD
With Guilherme Marques Martins
Tannins, the Backbone of Red Wine: Concepts and Craft with James Kennedy
With James Kennedy
Optimizing flavors and aromas in wine grapes: A case study of Riesling with Justine Vanden Heuvel
With Justine Vanden Heuvel
Postmodern Winemaking with Clark Smith
With Clark Smith
Viti 101: An Introduction to Viticulture with Tracy Kamens
With Tracy Kamens
Genetically Modified Vines and Yeasts with Christy Canterbury MW
With Christy Canterbury MW
Cultured vs Indigenous Yeasts with Christy Canterbury MW
With Christy Canterbury MW
French Oak: Forests, Coopers and Techniques with Roger Bohmrich MW
With Roger Bohmrich MW
Brettanomyces with Christy Canterbury MW
With Christy Canterbury MW
Organic, Biodynamic and Reasoned Viticulture with Roger Bohmrich MW
With Roger Bohmrich MW
Climate Change and Wine with Roger Bohmrich MW
With Roger Bohmrich MW
Soil and Wine: What do we really know with Roger Bohmrich MW
With Roger Bohmrich MW
Vine Stress with Christy Canterbury MW
With Christy Canterbury MW
Photosynthesis with Lisa Airey, CWE, FWS
With Lisa Airey
Pirates and Pyrazines with Lisa Airey, CWE, FWS
With Lisa Airey
The Barrel Regimen with Lisa Airey CWE, FWS
With Lisa Airey

Nova Cadamatre MW

Nova Cadamatre is a winemaker, writer, and blogger. As one of the first graduates of Cornell’s Viticulture and Enology program in 2006, Nova relocated to California to assume a number of winemaking roles. She has worked for numerous iconic wineries in CA including Robert Mondavi Winery, Souverain, Beringer, and Chateau St. Jean. She was also involved as a contestant in the Ningxia Winemaker Challenge making wine in Ningxia, China with Lansai Chateau from 2015-2017.

In 2017, she became the first female winemaker to become an MW in the US and in 2014, Cadamatre was named to Wine Enthusiast’s Top 40 under 40 list. She has numerous 90+ scoring wines to her credit and writes her blog at

Originally from Greer, South Carolina, Cadamatre began her career in wine after moving to New York to pursue horticulture. She splits her time between the Finger Lakes where she and her family have their winery, Trestle Thirty One, and Napa, CA where she is Director of Winemaking for Robert Mondavi Winery.


The opinions and views expressed in blog posts are those of the author of the post and do not necessarily represent the views of The Wine Scholar Guild or constitute any part of its educational programs.

1 comment

Sign up to receive our latest updates