What is Botrytis cinerea?

What is in a name? Botrytis cinerea is ignoble rot when it infects grapes resulting in bunch rot and grey mold, but under the right conditions, Botrytis cinerea can develop into noble rot capable of producing wines of immense sugar concentration. So what is Botrytis cinerea?^1,2

• Botrytis cinerea is a fungus
• The initial inoculum probably develops from overwintering mycelia which are strands of the living fungus that can survive on previously diseased tissues or from resting structures called sclerotia
• Grapevine flowers, immediately after capfall, and berries post veraison are particularly susceptible to botrytis infection.
• Infected flower parts located in the developing cluster may initiate fruit infection later during the season
• As the fruit reaches maturity, resistance to fungal growth declines and under moist conditions, new infections, incited by spores from external sources become important
• Botrytis relies on damaged tissue to begin an infection so any wounded green tissue is susceptible
• Grape varieties that produce thin-skinned, tightly packed bunches are prone to splitting and retain moisture, providing conditions that suit botrytis
• Botrytis susceptible varieties include Chardonnay, Chenin Blanc, Grenache, Muller Thurgau, Pinot Gris, Pinot Noir, Riesling, Sauvignon Blanc, Semillon, Traminer, and Sultana

Here is the lifecycle of Botrytis cinerea:¹

What are the conditions that can lead to noble rot?²

• Noble rot develops late in the season under conditions of fluctuating humidity, specifically humid nights followed by dry, sunny days which limits fungal growth
• Fall infection of Botrytis leads to the release of pectolytic enzymes that degrade the pectinaceous component of the cell wall leading to the dehydration of the grape under dry conditions
• This drying of the berry is crucial to the concentration of the juice
• Drying also limits secondary infection by bacteria and fungi including Penicillium, Aspergillus, and Mucor
• A distinctive feature of noble rotting is a loss in varietal aroma due to the destruction of terpenes that give these varieties their distinctive fragrance.

So, Botrytis cinerea, ignoble during the growing season producing bunch rot and grey mold, but noble under certain rare conditions which produces a desirable transformation into a dehyrated, highly concentrated grape enhancing it's quality.
References:
1. AWRI, Viti-Notes, Botrytis, 2010.
2. Ronald Jackson, Wine Science Third Edition, Elsevier, 2008, pg. 520- .

The Story of Our Wedding Bag Grapes

No matter how careful our harvesters are, there will always be some grapes that are left in the vineyard. We take advantage of this oversight, by putting wedding bags on these grapes. We think that the wedding bags are the key to getting the grapes to dehydrate and concentrate their sugars while providing safety from being the target of predators still looking for a sugar high.

As the leaves from the vines begin to fall, we are finding more grapes to bag. In the photo below, the bunch on the left was a bunch we found on November 10 and the bunch on the right was a bunch we found on November 21.

We have been making a late harvest Chenin Blanc since 2019 when we harvested the wedding bags on November 19, 2019. In 2020, we were not able to get to the wedding bags until December 11. Here is a photo of what the grapes looked like:

The 2020 late harvest Chenin Blanc yielded precious little liquid, but we did manage to ferment it and called the wine our version of The Most Expensive Wine, a Tokaji Essencia.
This year, we are carefully monitoring the transition of Chenin Blanc grape to botrytized raisin so that we don't go too far on the spectrum to raisin. Yesterday, while we were working in the vineyard, we gathered a few grapes and took the Brix measurement. Here is what we found:

2018 Braida Monte Bruna Barbera d'Asti

We are always on the lookout to try different Barbera wines because we also grow Barbera. Recently, my husband bought this 2018 Braida Monte Bruna. We liked it immediately. The wine was dark garnet in color and had notes of blackberries and boysenberries at the beginning which lingered until the finish of acidity at the back end.
I learned a little more about this Barbera at the Braida Website. Montebruna is a Barbera d’Asti DOCG made with 100% Barbera grapes grown in an estate-owned vineyard in Rochetta Tanaro. The must spends two weeks in temperature-controlled steel tanks where it ferments and is then transferred to large oak barrels to age for a year. My husband said he purchased this wine for about $32.00. Worth it!

Statistics for Our Varieties from 2019-2021

Since 2019, we have been taking our harvest to Jonathan Edwards Winery where Jon and his crew help us to press the grapes and turn the juice into wine. I thought that it would be interesting to compare the harvest date, weight, volume, Brix, and TA of the varieites that we grow in the vineyard. We also grow Barbera, but that variety is still maturing and we are making this wine in our basement.
Auxerrois

Auxerrois	Harvest Date	Weight/ Lbs	Volume of Juice/ Gallons	Brix	pH	TA
2019	September 23, 2019	636	50	19.6	3.23	7.35 g/L
2020	September 27, 2020	1670	133	19	3.07	7.5 g/L
2021	September 28, 2021	1638	130	18	3.25	7.2 g/L

Chenin Blanc

Chenin Blanc	Harvest Date	Weight/ Lbs	Volume of Juice/ Gallons	Brix	pH	TA
2019	October 14, 2019	3920	305	21.6	3.15	13.5 g/L
2020	October 11, 2020	8201	655	23.3	3.09	12.1 g/L
2021	October 17-18, 2021	6200	496	20.4	3.17	14.6 g/L

Chardonnay

Chardonnay	Harvest Date	Weight/ Lbs	Volume of Juice/ Gallons	Brix	pH	TA
2019	September 28, 2019	291	26	21.5	3.17	9.4 g/L
2020	September 24, 2020	1136	80	23.5	3.0	10 g/L
2021	October 3, 2020	2625	210	20.4	3.28	8.2 g/L

Cabernet Sauvignon

Cabernet Sauvignon	Harvest Date	Weight/ Lbs	Volume of Juice/ Gallons	Brix	pH	TA
2019	November 3, 2019	332	30	19	3.25	11.1 g/L
2020	October 22, 2020	888	80	22.4	3.08	10.7 g/L
2021	October 24, 2021	561	45	20.1	3.07	10.4 g/L

Cabernet Franc

Cabernet Franc	Harvest Date	Weight/ Lbs	Volume of Juice/ Gallons	Brix	pH	TA
2019	October 26, 2019	377	32	23	3.23	11.3 g/L
2020	October 22, 2020	872	80	23.3	3.27	11.3 g/L
2021	October 24, 2021	402	32	19.8	3.2	7.4 g/L

It's interesting to see if there are any trends developing. One thing that is clear is that 2020 was an outstanding year for ripening and it is reflected in the wines we made in 2020.

Next Steps for our 2021 Barbera

We harvested our Barbera on Monday, October 25, just ahead of a nor'easter that was headed for our region the following day. We hand destemmed the small amount of Barbera that we harvested and used the yeast, F83 for our fermentation which we started on October 28.
We did daily punch downs so that the cap would be submerged in the liquid so that it would not be a substrate for Acetobacter to grow on.

On November 1, after verifying that the Barbera had finished fermentation, we pressed the wine away from the skins. Since we had a very small amount of wine, we used a huge colander which was placed over a clean 5-gallon food grade bucket. We also used a mash bag between the collander and the 5-gallon bucket and this effectively removed much of the larger particles from the juice. After we did this, we used a funnel to put the wine into a 6-gallon glass carboy.

In the above picture, you can see on the right hand side the sediment that has settled. Next steps for us is to rack this wine into a smaller container.

Shatter During Fruitset

We're doing a retrospective analysis on our somewhat low yields in our vineyard this year. The one variety that exceeded last year's weight at harvest was the Chardonnay. Coincidentally, the Chardonnay was the first to bloom around June 10 and reached approximately 30% bloom by June 13.
Most of our varieties were at some stage of bloom between June 10 and close to the end of June. On June 16 the following varieites were at this stage:

• The Auxerrois is beginning to bloom
• The Chenin is not in bloom
• The Chardonnay at about 50% bloom
• The Cabernet Sauvignon at about 20% bloom
• The Cabernet Franc at about 20% bloom
• The Barbera at about 10% bloom

Those flowers which bloomed early encountered rain on June 14, June 22, July 2 and July 3. One thing that we did notice during fruitset was the very sparse appearance of the fertilized berries.

This condition is known as shatter in the grape world. During the early summer, we had no idea of the impact of shatter on our yields. I looked online and found a very good article from the University of Maryland Extension on Grape Fruit Set and Shatter (Coulure) written by Joseph A. Fiola, Ph.D. In the article, Dr. Fiola mentions the following factors that can lead to decreased fruit set:

• Pre-bloom cultural practices such as shoot trimming or leaf pulling
• Nutrient deficiencies
• Deficiencies of any of the essential mineral nutrients can affect fruit set detrimentally
• Pre-bloom or post-bloom exposure to hormonal herbicide drift/volatilization
• Disease, insect, or other biotic stress before bloom can decrease fruit set
• Weather/Environmental conditions, including excessive heat (> 32°C/ 90°F) or cold (<15°C/59°F) can adversely affect pollen development, pollination, and fertilization
• Water stress can adversely affect fruit set
• Differences in cultivars

Of all of the above factors that affected our fruit set, I believe that weather conditions, as noted, rain during the period of flowering and fruit set affected our lower than expected yields this year.
References:
1. Joseph A. Fiola, Grape Fruit Set and Shatter (Coulure), University of Maryland Extension.

2019 Vernaccia Di San Gimignano

My husband bought this 2019 Vernaccia di San Gimignano from a local package store and we served it with appetizers of Brillant Savarin and sausage on crackers. The wine was fresh and easy to drink, reminding us of a Sauvignon blanc.
The grape, Vernaccia di San Gimignano was one that was not familiar to me so I went to the "grape Bible", Wine Grapes to learn more about it.
The Vernaccia di San Gimignano grows in the hill town of San Gimignano in the province of Siena in Toscana, Central Italy. It is a vigorous, mid- to late-ripening variety providing regular and generous yields. The maker of this bottle of Vernaccia is Fontaleoni, which is recommended in Wine Grapes. The picture on the label is a reference to the many towers in the town of San Gimignano.
This wine is very quaffable and the best thing is that it is around $15.00 a bottle!
References:
1. J. Robinson, J. Harding and J. Vouillamoz, Wine Grapes - A complete guide to 1,368 vine varieties, including their origins and flavours, pg 1019-10201131-1132, Allen Lane 2012 ISBN 978-1-846-14446-2.

Vintage 2021: Our 2021 Harvest at a Glance

All of our grapes have been harvested and on their trajectory to wine. It's a good time to recap our harvest for 2021.

Variety	Harvest Date	Weight/ Lbs	Volume/ Gallons	Brix	pH	TA
Auxerrois	9/28/2021	1638	130	18	3.25	7.2 g/L
Chenin Blanc	10/17-18/2021	6200	496	20.4	3.17	14.6 g/L
Chardonnay	10/3/2021	2625	210	20.3	3.28	8.3 g/L
Cabernet Sauvignon	10/24/2021	561	45	20.2	3.07	10.4 g/L
Cabernet Franc	10/24/2021	402	32	19.8	3.20	7.4 g/L
Barbera	10/25/2021	60	5	23	3.23	10.3 g/L

For all of our varieties with the exception of Chardonnay, we had a lighter than expected harvest. We attribute that to some event that happened in our vineyard during fruitset where at harvest we were left with clusters that were very loose. This looseness worked in our favor for the Chardonnay which typically experiences some form of fungal attack but this year, we had beautiful, loose clusters.

This year was a bit of a challenge with rain and humidity throughout the grape growth period. However, the grapes were as clean as they could be given the conditions.

Vintage 2021: Barbera Harvest

After harvesting the Cabernet Sauvignon and Cabernet Franc, we had one more harvest to do, which was our small amount of Barbera. It might have been a larger harvest had we been a little faster at netting the ripening grapes. As it was, we didn't get to it before the deer efficiently ate most of the grapes on the east side of the trellis, which is nearest to the outer perimeter of our vineyard. Well, live and learn!
We were able to fit in the Barbera harvest in the morning, on Monday, October 25, before going to Jonathan Edwards winery to destem the Cabernet harvest that occurred on Sunday, October 24. My husband and I were able to harvest the Barbera in one hour.

We were able to harvest about three lugs worth of Barbera, which we approximated to be 60 pounds. We took the stats for the Barbera and it was:

Variety	Weight	Volume of Juice	Brix	pH	TA
Barbera	60 pounds	5 gallons	23	3.23	10.3 g/L

Turns out that harvesting the Barbera was the easy part. We hand removed each grape from the rachis (the grape stem), and the berries filled two 5-gallon buckets in preparation for inoculation with our yeast, F83.

On October 28, we rehydrated 5 grams of our yeast, F83 in 50 mL of spring water. After 20 minutes, we added the Barbera juice in 10 mL aliquots every ten minutes. Around 3:02 we inoculated the two buckets of Barbera with the rehydrated and tempered yeast.
We know that fermentation is occuring because the cap is rising to the top due to the release of carbon dioxide. We "punch down" the fermentation twice a day to prevent the cap from being a home to acetobacter.