Salvo Foti, the pillar of tradition in Mt Etna winegrowing

For most of it lengthy vinous history, the Mt Etna region has utilized the albarello training system as the foundation of its viticultural regime. This system reigned supreme until growers turned to the Guyot and speranato cordone (cordon spur) systems in the early and middle portions of the 20th century. As explained to me by Salvo Foti during a recent conversation, if you went back 20 years, most new plantings were Guyot, as growers pursued the perceived benefits of mechanization and increased yields. As a result, he said, we (the Etna growers) have lost our patrimonial history. But now things are looking up, he continued, as small producers are going back to albarello for new plantings.

Viticulture on the mountain is a mix of the traditional and these "newer" training systems and associated practices. There is no fiercer proponent and advocate of the traditional approach than the aforementioned Salvo Foti.  I provide some insight into Mr Foti's philosophy and practices in this post.

In their seminal work on Sicilian wine (The World of Sicilian Wine), Nesto and di Savino describe the subject thusly: "Salvo Foti stands out, by himself, as Sicily's greatest homegrown consulting enologist ..." who "... more than any other person, ... has fostered an awareness of (Etna's) unique wine culture."

Salvo Foti with Lidia Rizzo, Contrada Caselle

According to Nesto and di Savino, Foti's grandparents owned vineyards on the slopes of Etna. Salvo gained a technical degree in enology on the 1980s and began consulting work with a number of producers in Sicily. He continued his studies and eventually received a specialized degree in enology from the University of Catania. When Giuseppe Benanti made the commitment to the production of high-quality wine on Etna, he turned to the young Foti to work with him on the needed experiments. Foti was Benanti's enologist until they parted ways in 2011.

In his writings (Foti has written a couple of books and a number of pamphlets on wine-related topics), Foti draws a sharp contrast between "producing Etna wines" and "making wine on Etna." Producing an Etna wine results in a product that "captures the essence of the land, the environment, and the people;" requires a winemaker who is "committed to improving and preserving the land where she or he operates," and a vineyard that is ...

in harmony with the terroir, is naturally integrated with the Etna volcano and is expressed in vertical: lives and grows upwards (leaves and shoots to the sky, in lavic stone terraces) and down in the depth (roots), in opposite directions but complementary between them (Salvo Foti, Applied Viticulture, Book 4, The Etnean Palmento: the traditional vinification).

Foti's core mission, as described by Nesto and di Savino, is:

• Protection of the land
• Preservation of albarello viticulture
• Cultivation of indigenous vine varieties
• Emphasizing the humanity of the grower
• Conservation of Sicilian culture.

His key viticultural principles are:

• The use of the albarello training system
• Dense vine spacing
• Avoidance of systemic sprays and synthetic soil additives
• Chestnut poles for vine support.

Foti's key principles on display at Aeris Vineyard

In Foti's view (expressed in my conversation with him), albarello is perfect for grape maturity: (i) the leaves cover the grapes, affording protection from the sun's direct rays and (ii) it affords the capability of working around the vine. He is not a big fan of non-albarello training systems (Foti, The Verticality of Etna):

In the Etna, the vineyard cultivated in the horizontal way (destruction of the terraces to make flat the land, cultivation of the vineyards in the espalier system) is a forcing system for the vine, intended only for the mechanization and for the quantity. 

Foti has been very proactive in disseminating his thoughts and practices:

• I previously mentioned the books and pamphlets
• Salvo has formed an organization called I Vigneri which is comprised of like-minded grape growers and producers operating in Etna and eastern Sicily. In addition to work on their personal properties (if so endowed), members of the organization are available to work the vineyards of clients, all work based on the I Vigneri principles.
• He has guided new Etna winemakers, such as Ciro Biondi and Alice Bonaccorsi, and has served as consultant to Edomé, Romeo del Castello, and Il Cantante, among others.
• Salvo's work on Pietra Marina caught the eye of Kevin Harvey of US-based Rhys Vineyards and they eventually entered into a partnership to grow Carricante grapes at the Aeris Vineyard in Contrada Caselle. But that is not the end of the story. Salvo is also planting a Carricante vineyard for Harvey in California, using I Vigneri practices and personnel.

In our conversation Salvo emphasized that his focus was on respect for the people and the environment. In the Mt Etna region they have been doing the same thing for over 200 years. The viticulture and the people have evolved together and he sees no reason to change that dynamic. He feels strongly that he has a responsibility to the people and the native varieties of the region to ensure their continuity.

And that continuity extends to his farming and management of the land. His grandfather and father worked Carricante. He is farming the way they did. They passed the practices and principles on to him and he is passing it on to his son Simone. And hopefully Simone will pass it on to his son. Continuity.

Foti with his son Simone

Simone, Salvo, Lidia Rizzo, and Brandon Tokash

Salvo Foti and author (Photo credit Lidia Rizzo)

Foti is a quiet and soft-spoken man. At least those were the characteristics that he projected during the course of our meeting. But he also impressed as being extremely knowledgeable, having a strong sense of self, commitment to a set of ideals, and intensity of purpose. Albarello could not have happened upon a stronger proponent.

©Wine -- Mise en abyme

The major Etna DOC grape varieties

The Etna DOC has established the following wine and labeling requirements:

• Etna DOC Rosso -- to be made from the indigenous varieties Nerello Mascalese (> 80%) and Nerello Cappuccio (< 20%) plus up to 10% of other non-aromatic grape varieties (red or white)
• Etna DOC Rosato -- same as for Rosso
• Etna DOC Bianco -- to be made from Carricante (> 60%), Catarratto (< 40%), and up to 15% of other non-aromatic grapes such as Minella or Trebbiano
• Etna DOC Bianco Superiore -- to be made from Carricante (> 80%) and Catarratto or Minnella (< 20%). All grapes to be sourced exclusively from the area of Milo on the eastern side of the volcano.

I continue to flesh out my understanding of the Etna DOC viticultural  environment with the following post on the main grape varieties included in the DOC specification.

White Varieties
Carricante
Carricante is an ancient white variety -- prevalent on Mt Etna's eastern face -- that yields low-potassium, low-pH, high acidity wines (benanti.it). The bunches are of average length at ripening, with medium-sized berries of a green-yellowish color.

Carricante (tenutaterrenere.com)

Frank Cornelissen, one of the leading winemakers on the mountain, has historically viewed the variety as too acidic to produce world-class wine. Ian d'Agata, author of Native Wine Grapes of Italy, on the other hand, is quoted in Szabo's Volcanic Wines thusly: "potentially one of Italy's greatest cultivars ..." that "... when properly tended to, yields wines of great longevity and intense mineral character."

According to Salvo Foti, long-famed viticulturist, Carricante vines have to be somewhere between 10- and 15-years old in order to begin giving great concentration. Salvo said that both his father and grandfather worked Carricante and the wine's high acidity was extremely important in the days before widespread access to refrigeration. The wine is also great for raw fish, the main dish in the area.

There is a saltiness in the east side Carricante that is lacking in wines made from grapes grown on the north side of the mountain. For Salvo, typicity is the key; and he sees Carricante as the grape for this place.

There are some 100% Carricante wines on the market but the grape is usually the primary varietal in an Etna DOC wine. It is also used, at lower elevations, to lighten the color and body of Nerello Mascalese and Nerello Cappucchio blends.

Catarratto
Catarratto is a high-yielding, low-acidity Sicilian grape variety. It is the main grape used in the production of Marsala but on Etna is primarily blended with Carricante. There are two clones -- Commune and Lucido -- with the former having more acid and less sugar than the latter as well as being the clone of choice on the mountain.

Catarratto (etnawine.it)

Catarratto does not engender as much discussion on the mountain as does Carricante.

Minnella
Minnella is a white-berry vine that is indigenous to Etna where it is mostly found in old vineyards interplanted with Nerello Mascalese and Carricante. This is an early ripening variety.

Reds
Nerello Mascalese
Nerello Mascalese is the most important variety on Mt Etna. In older vineyards in can be found interplanted with Nerello Cappucchio while newer plantings position these varieties into separate rows or blocks to facilitate cellar rather than field blends.

Nerello Mascalese (tenutaterrenere.com)

The vine is vigorous and is readily affected by:

• Vintage conditions
• Cultivation area
• Training system
• Density
• Cultural practices.

The wines from the variety are mildly sweet and "distinctively tannic." Szabo compares it to Pinot Noir and Nebbiolo both in color and the ability to reflect even minor variations in terroir.

Benanti sees the best training system for the variety as follows:

• Free standing bush with 2 - 3 branches per tree
• High vine density -- 6000 - 9000 vines /ha
• Spacing of 1 x 1 or 1.25 x 1.25.

Nerello Cappuccio
This variety's medium-to-small-sized bunches and medium-sized grapes produce wines with good acid and tannin levels. The variety buds and ripens earlier than Nerello Mascalese with the former characteristic bringing the negative effects of late spring frosts into play.

Used primarily in a blend with Nerello Mascalese, this grape brings color and perfume to the blend as well as serving to soften up some of the harder edges of its partner.


©Wine -- Mise en abyme

Hyperoxidation: White winemaking jujitsu

According to dictionary.com, jujitsu (or jiujitsu) is "a method developed in Japan of defending oneself without the use of weapons by using the strength and weight of an adversary to disable him."

Jujitsu training at an agricultural school in
Japan circa 1920 (Source: wikipedia.com)

Hyperoxidation, a white winemaking mechanism which utilizes oxidation effects during the juice phase of winemaking in order to avoid its effects later on in the bottle, is winemaking jujitsu.

I previously described the process whereby white wines are oxidized and the resulting effects. To summarize, the enzyme Tyrosinase (laccase in the case of botrytized must) catalyzes the formation of caftaric acid quinone, the result of the oxidation of the phenol caftaric acid. The quinone reacts with glutathione (a naturally occurring tripeptide found in grapes; and itself a powerful antioxidant) in the juice to form the colorless complex Grape Reduction Product (GRP). Once the glutathione is fully utilized, GRP is no longer formed and oxidation proceeds unencumbered (This process is called enzymatic oxidation. For a fuller description of this process, as well as the non-enzymatic oxidation of wine, see here.). The results of oxidation in white wines are browning, loss of fruity aromas, and gain of aldehydic aromas.

According to Jackson (Wine Science), "In contrast to red wines, the limited antioxidant character of white wines (ed: tannins and anthocyanins provide substantive antioxidant capability in red wines) make them more susceptible to oxidative browning." Further, grape varieties differ markedly in the amount of phenolics released during crushing or extracted during maceration (an extremely important consideration given that phenolics are the main substrate for oxidation activity). The table below shows the levels of flavonoid accumulation during crushing or maceration of selected white varieties.

Table 1. Phenolics released/extracted during crushing/maceration

Variety	Flavonoid Accumulation
Palomino	Low
Sauvignon Blanc	Low
Riesling	Moderate
Semillon	Moderate
Chardonnay	Moderate
Muscat Gordo	Extensive
Colombard	Extensive
Trebbiano	Extensive
Pedro Ximinez	Extensive

In the case of hyperoxidation, the deliberate introduction of oxygen into the juice causes enzymatic oxidation of the phenols. The process entails adding large amounts of oxygen to the juice, allowing it to settle, and then racking it from the brown precipitate just prior to fermentation. This oxidation will cause browning of the juice but the phenols will have been polymerized and will precipitate out.

Clarification is required to reduce the suspended solids to less than 1% by weight in order to remove the major part of the phenolic precipitate. This clarification must be completed before fermentation begins as the precipitate will re-dissolve in alcohol. The clarified juice will retain a brown color but this residual browning will be eliminated by the reducing conditions of alcoholic fermentation and absorption by yeasts (Schneider, Hyperoxidation: A Review, AJEV, 1998).

The brown pigment absorbed by the yeasts during alcoholic fermentation will fall to the bottom of the tank with the lees and can be removed in a post-fermentation racking. Fining and/or filtration can be utilized for additional clarification if required.This process renders the wine less susceptible to in-bottle browning (due to the elimination of the phenols) as well as reduces bitterness in the wine.

Hyperoxidation requires that SO2 additions be withheld from the must as the oxidative enzymes are inhibited in its presence. For example, tyrosinase registers a 90% decrease in activity when 50 mg/L of SO is added to the must. SO2 also reduces caftaric acid quinone and enhances the solubility of phenolic molecules. . These effects will limit the extent and effectiveness of the hyperoxidation. The implementation of hyperoxidation can thus allow for the production of low-sulfur wines.

Hyperoxidation, then, uses the strength of oxidation in the early stages of winemaking to neuter the substrate in the early stages of winemaking and prevent it from becoming an oxidation resource in the bottle. Jujitsu.

©Wine -- Mise en abyme

An architecture for the production of reductive white wines

Traditionally, wine has been made in an oxidative style. But, beginning in the 1950s and 1960s, grape growers and winemakers began to employ new tools to attain specific "stylistic and qualitative ends."

Based on Clark Smith's interpretation of the history of that period, the "tools of 20th century winemaking" were stainless steel, inert gas, refrigeration, and sterile filtration (a product of nuclear energy) and this "modern winemaking revolution exploded out of Germany" in the form of Rieslings that were fresh, sterile-filtered, and completely without oxidative characters. According to Smith: "the idea of a light, sweet, fresh, fruity wine like Blue Nun was as world changing as color television." 

These tools and techniques were adopted by Emile Peynaud and other scientists in France and, from there, migrated to the US. According to Smith, prior to the 1960s, 95% of California wines were either port or sherry styles. With the introduction of Blue Nunn, and the adoption of the associated technologies in Bordeaux, US winemakers followed suit such that, by 1970, the majority of California wine contained less than 14% alcohol. These tools and techniques allowed the introduction and use of a reductive style of winemaking.

Hydrogen sulfide is the result of a severe case of reduction in wine but, lower down on the scale, Benzene thiol and furfural thiol contribute bread crust, smoke, and struck flint aromas. Fruity thiols provide notes of passion fruit, citrus zest/cat pee, and grapefruit, aromas associated with Sauvignon Blanc (Remy Charest, Fashionable Chemistry ..., nomacorc.com; Jackson, Wine Science). But it is preservation of freshness and fruit aromas and flavor that the winemaker pursues when he/she decides to employ a reductive winemaking style.

The essence of reductive winemaking is the production of wine without the presence of oxygen. Grapes are harvested from cool regions and the juice is fermented cold in closed stainless steel tanks. Juice is protected as is the wine through maturation and bottling. This method is particularly beneficial for grape varieties such as Sauvignon Blanc, Petit Manseng, Chenin Blanc, and Gewurtztraminer that are rich in varietal aromas that can be placed at risk in the face of oxidizing effects.

The winemaker's plight in producing a reductive white wine
(Underlying picture source: http://cdn.pcwallart.com/)

Before I get into the elements of the architecture, I would like to highlight a Remy Charest report wherein he illustrated a shift to reductive winemaking among Burgundy producers. According to Remy, Jancis Robinson had written about in a shift in Burgundy from buttery, rich, toasty Chardonnays to Chardonnays that exhibited:

• High acidity
• No trace of toastiness or obvious oak
• Leanness on the palate
• The flinty smell of recently struck match.

In her discussions with Jean-Marc Roulot (Domaine Roulot), she was told that this result was largely due to a more reductive style of winemaking, itself a reaction to the premox crisis that rocked the region's white wines in the 1990s.

Remy described the reductive program as:

• Long, slow, delicate pressing
• Protection from oxygen through vinification and aging
• Finishing the aging in tank

Some additional (and widely accepted, though not necessarily reductive) characteristics of these wines include:

• Relatively high SO2 addition (Probably related to the battle against oxidation but may also be linked to the appearance of the struck-match character in some of the wines).
• Fresher, crisper wines resulting from earlier pick dates and moving vineyards to cooler sites.

Reductive white wines are all the rage today but, as Lance Cutler (Achieving Balance in Reductive Winemaking, Wine Business) points out, "Keeping wine away from oxygen can create some vibrantly fruity wines, but this same lack of oxygen might encourage the development of reduced sulfur compounds."

The main considerations in producing a reductive white wine are as follows:

1. Healthy fruit from a cool vineyard. The climate in the vineyard will help to preserve freshness and crispness of aromas while healthy fruit will have an adequate supply of the vitamins and minerals to ensure a successful fermentation. The viticultural factors affecting the supply of yeast assimilable nitrogen include: cultivars, rot incidence, block, vineyard mulch, crop load, moisture stress, and grape maturity level (Zoecklein)
2. Minimize the use of sulfur in the vineyard and ensure adequate time spacing between application and harvest
3. Harvest at night to preserve freshness and flavors
4. Application of inert gases during harvest (mainly CO₂ in dry-ice form)
5. Provide antioxidant treatment to the free-run juice. Most normally ascorbic acid and sulfur dioxide but there is some concern that ascorbic acid switches from protection to oxidative mode over the long term and, as such, is not suited for wines destined for aging. In many cases inert gases such as CO₂ and N₂ are used to protect the juice from oxygen.
6. Measure fermentable nitrogen as too high, or too low, concentrations can result in the formation of undesirable sulfur compounds during fermentation. According to Zoecklein these measurements can be carried out with either Formol titration or a NOPA test.
7. Turbidity should be adjusted such that stylistic goals and aromatic finesse of the wine is achieved. Juice clarity should be measured in Nephol units and should fall between 100 and 150 (Zoecklein)
8. Non-soluble solids concentration should be monitored as both high and low concentrations can result in the production of undesirable sulfur compounds
9. The appropriate yeasts should be selected for the effort as strains differ in their capacity to transform the non-volatile grape derived precursors to odor-active volatiles (Zoecklein)
10. Keep yeast cells suspended in the tank during fermentation in order to allow an even distribution of fermentation as well as to allow full access to distributed nutrients
11. Rack gently under a carbon dioxide or nitrogen blanket. Use an in-line sparging device to sparge the wine with CO₂ or N₂. Add SO₂ to the wine as it is being racked to prevent oxidation
12. No malolactic fermentation in order to preserve varietal character, flavors, and freshness
13. No oak aging in order to continue to continue to deny oxygen access to the wine
14. Select an appropriate closure. According to Remy Charest, "Precise control of oxygen in the bottle, for example by selecting a closure allowing small and consistent amounts of oxygen, can prevent extreme reduction without compromising the more interesting flinty and fruity aromas."

In the cases where the odors are manifested in the wine, remedies include (i) blowing it off through volatility; (ii) inert gas sparging; (iii) precipitating with copper additions; and (iv) fining.

©Wine -- Mise en abyme

Walking the tightrope between oxidation and reduction in white wine production: Reduction

Reduction is the other side of the oxidation/reduction coin. When elemental oxygen combines with wine compounds, it can take a pair of electrons from the compound. The compound losing the electrons is said to have been "oxidized" while the oxygen, which has gained two electrons, is said to be "reduced."

Reduction is of principal importance to the winemaker as it relates to sulfur compounds. According to Jackson (Wine Science):

When present, elemental sulfur can be assimilated and used in the synthesis of sulfur-containing amino acids and coenzymes. It also may be oxidized to sulfate and sulfur dioxide or reduced to hydrogen sulfide. The reduction of sulfide to hydrogen sulfide may be a means, albeit aromatically unpleasant, of maintaining a favorable redox balance in yeast cells under anaerobic conditions.

According to Zoecklin (Enology Notes #96, 12/20/2004, vtwines.info):

Since wine is fermented by yeast through an anaerobic process (without oxygen), a number of reduced compounds are produced. Reduced sulfur and and nitrogen compounds, in the form of hydrogen sulfide and mercaptans (ammonia and amines), are known particularly for the negative characters they impart to wines. Thus, it is possible to have a wine with an unpleasant and undesirable reduced character.

The sulfur compounds associated with sulfur taint, and the population of odors associated therewith, are illustrated in the figure below.

Sulfur taint has its origins in either the vineyard, the cellar, or both. In the vineyard, elemental sulfur is sprayed on the vines to combat the potential effects of powdery mildew. If this spraying is conducted too close to harvest, portions of the sulfur will remain on the grapes and make its way into the fermentation process. An example of sulfur-like off odors created in the cellar is the case of hydrogen sulfide production by the yeast to synthesize the sulfur-containing amino acids methionine and cysteine. This process is facilitated by the reduction of sulfates via the sulfur-reduction pathway. A lack of intracellular nitrogen will not curtail the process and the excess hydrogen thus created cannot be incorporated into the amino acid. Rather, it is secreted into the medium (Kennedy and Reid, Yeast nutrient management in winemaking, The Australian and New Zealand Grapegrower and Winemaker, 537, October 2008).

A listing of the sources of sulfur-like off odors is presented in Table 1.

Table 1: Sources of sulfur taint in wine production.

Environment	Source	Action	Impact
Vineyard	Elemental sulfur used as fungicide	Reduction during fermentation
	Sulfur-containing pesticides	do.
	Excess of metal ions
	Vine stress
	Unsound fruit
Cellar	Cold soaking	Growth of yeasts such as Kloeckera	Depletion of amino acids and micronutrients
	Native Yeasts	High hydrogen sulfide production	Compete against other yeasts for dominance of fermentation
	Excess hydrogen sulfide from sulfate reduction	Hydrogen sulfide used to synthesize	Absence of nitrogen causes produced hydrogen sulfide  to be secreted into the medium
	High levels of sulphur dioxide added to must at crush	Allows sulphur dioxide to bypass the sulfate reduction system	Sulfur dioxide enters the yeast cell directly
	Vitamin shortage in high YAN musts
	Nitrogen limitation	Produces sulfur-like off odors	Production begins 30 minutes after ammonia starvation initiates

Source: Compiled from Lansing and Kennedy and Reid)

The timing of the production of sulfur-like off odors is shown in Table 2 below.

Table 2. Production timing of sulfur taint by sulfur class.

Sulfur Class	Production Timing	Source
Hydrogen Sulfide	Early in fermentation (2 - 4 days)	Nitrogen/vitamin deficiency
	Fermentation end	Degradation of sulfur-containing compounds
	Sur lie aging	Autolysis
	In bottle	Generally under screw cap
Higher Sulfides	Late in fermentation/Sur lie aging	Release of compounds by metabolically active yeasts Degradation of sulfur-containing amino acids Degradation of cell compounds during autolysis

Source: Compiled from Lansing

In the cases where the odors are manifested in the wine, remedies include (i) blowing it off through volatility; (ii) inert gas sparging; (iii) precipitating with copper additions; and (iv) fining.

Oxidation and reduction are twin evils in the world of (especially) white wine production but there are aspects of both that are beneficial to the final product. Making wines which call on these qualities is called oxidative and reductive winemaking, respectively, and I will cover those styles in upcoming posts.

©Wine -- Mise en abyme

Walking the tightrope between oxidation and reduction in white wine production: Oxidation

In this series I will be examining the winemaker's challenge in navigating between the twin evils of reduction and oxidation, both faults but both having potentially desirable characteristics close to the center of the continuum. I begin with this post on oxidation.

According to Lukacs' research (Inventing Wine), modern wine did not arise until the advent of the relevant scientific and technological advances of the Enlightenment. Prior to that period, wine drinkers consumed oxidized, sour wines which were "fortified" with all manner of additives designed to either slow its decay or make it more "palatable." Lukacs points out that winemaking in the first half of the 20th century was a reprise of thousands of years past -- "a process of letting nature run its course."

When Emile Peynaud (famed Bourdeaux enologist) began his work in the early 1950s, growers were harvesting early and, as a result, the wines were "excessively green or vegetal." He observed that there was a further striking uniformity about the wines: they were all oxidized.

Wine oxidizes when exposed to air via two primary mechanisms: enzymic and non-enzymic oxidation.  The effects of oxidation on white wine are browning, loss of fruity aromas, and aldehydic aromas. Because of these characteristics, oxidization is widely viewed as a wine fault.

Enzymic Oxidation

Enzymic oxidation (which primarily afflicts wine must) requires the presence of the enzyme Tyrosinase* (or Laccase**, in the case of botrytized must), phenolic compounds (hydroxycinnamic acids, with the main player being caftaric acid but others — including coumaroyl, tartaric acid, and catechin — as alternates) to perform the role of substrate, oxygen, and metallic co-factors (iron, copper, etc.). These enzymes interact with the substrates to form caftaric acid quinone which, in turn, reacts with glutathione (normally a powerful anti-oxidant) in the must to form Grape Reduction Product (GRP). The conversion of the oxidized quinone to GRP limits the browning of the juice to some extent (duToit and Kritzinger). Once the glutathione is depleted, the remaining caftaric acid quinone reacts with other must constituents to form caftaric acid and begins the oxidation process anew. Browning occurs when the flavanols oxidized by caftaric acid quinones polymerize and precipitate out. Unlike the case of wines, these brown pigments are insoluble in must.

Because tyrosinase is associated with grape solids, its enzymic activity is significantly diminished once the solids have been removed from the equation. Laccase is difficult to eliminate from grape juice.

The activity of these enzymes will be impacted by (Boulton, et al, Principles and Practices of Winemaking):

• The concentration of major phenols
• Competition between substrates for binding and reaction
• The caftaric and glutathione content of cultivar (the state at which glutathione is depleted will determine the level of potential browning)
• The ascorbic acid content
• Temperature
•  Wine pH.

Both tyrosinase and laccase use catechin, anthocyanin, flavanols, and flavanone as substrates but, as indicated in Table 2.1 of Boulton et al., laccase acts on a far wider range of substrates than does tyrosinase. UCDavis pegs the added scope of laccase as encompassing anthocyanin pigments and ascorbic acid, the latter of which is itself used as an antioxidant

Non-Enzymic Oxidation

Non-enzymic oxidation, also known as chemical oxidation, occurs in fermented wine. In this case, oxygen does not react directly with phenolic compounds. Rather, it functions through a reaction catalyzed by Cu+ or Fe+ that converts oxygen into a highly reactive radical capable of oxidizing organic compounds.

Non-enzymic oxidation in white wines can result in premature aging, browning, and pinking, all resulting in wine deterioration and loss of quality. Strategies for combating this fault include removing metals -- oxidation catalysts -- and reducing the concentration of phenolic compounds -- oxidation precursors --in wines.

©Wine -- Mise en abyme

MACDONALD: Site and practices combine for an excellent representation of the To-Kalon legacy

A 43-acre plot of the historic To-Kalon Vineyard was purchased in 1954 from the Stelling estate by Mrs. Hedwig Detert, Greatgrandmother to the generation currently growing grapes on that selfsame property. Shortly after the purchase, Mrs. Detert apportioned the property between her two children and those plots are currently farmed by her GreatGrandchildren under the names Detert Family Vineyards (25 acres) and MACDONALD (21 acres, inclusive of a subsequent purchase of 3 acres from Robert Mondavi for property construction). The Detert and MACDONALD plots are shown in the map below.

Map of the historic To-Kalon Vineyard and
 "Stelling Extension" (Drawn by Sarah MacDonald)

MACDONALD is currently operated by siblings Alex and Graeme MacDonald. I recently visited and walked the vineyard with Graeme and have split reporting on that encounter into a post on the history and this one on the vineyard and wine.

I got to the MACDONALD offices a little early (plus I had missed the turn) and came onto the premises from the rear. I asked a man who was mowing the lawn for directions to Graeme and he pointed me to a walkway and a cottage at its termination point. I walked up to the door and knocked and it was opened by Sarah (Graeme's wife) who was quickly shuffled out of the way by a toy-toting tot and a similarly equipped dog. Graeme was on his way from St Helena so Sarah invited me in and provided a folder of To-Kalon artifacts for me to feast my eyes on while I waited.

Graeme showed up soon after and apologized profusely for the delay. He had a nice easy smile and conversational tone. I knew right away that it was going to be a good day. He suggested that we go outside and walk the vineyards so I said goodbye to the toy-toters and struck out into the vines. We circumnavigated the vineyard in a counter-clockwise direction.

As shown in the map above, the MACDONALD plot is just outside the foothills of the Mayacamas Mountains, on an alluvial fan that has been created by Tokalon Creek bringing gravel, stones, volcanic rock, and sand down from the mountain and depositing it in a fan-like shape onto the valley floor. The fan forms deep gravelly soils with excellent drainage and forces the vine roots to go deep underground in search of water. This action places stress on the vine, resulting in small berries (according to Graeme, they are the smallest berries in the Mondavi stable) and optimal ripening.

Towards the bottom end of the alluvial fan the soil is shallower, has a higher percentage of clay, and is more fertile. This latter fact was demonstrated by the size of the trees lining the path separating the MACDONALD and Mondavi vineyards. At the upper reaches of the path, the trees were about 8-feet tall while towards the bottom they are twice that height. A sample of the various soil types present  on the MACDONALD plot is shown in the pictures below.

Tokalon Creek

Graeme is responsible for vineyard management and winemaking at MACDONALD. He subscribes to what he calls natural farming, a requirement, he says, for getting natural flavors out of the grapes:

• Integration of plants into the environment
• Minimal tractor use to minimize compaction
• No fertilizers -- planting of Fava beans between rows
• No roundup
• Minimal canopy management (only one trellised block in the vineyard)
• Creation of their own compost on site.

The vineyard is oriented NE - SW which allows fuller access to the morning sun and limited access to the searing afternoon sun. Vines are 20-, 40-, and 60-years old with the youngest vines California-sprawl-trained and the oldest head-trained. Graeme is able to get away with minimal canopy management because, he says, the California sprawl creates its own balance. The trellised vines are planted at 1089 vines/acre while the rest of the vineyard is planted to 565 vines/acre.

The vines are all Cabernet Sauvignon: Clone 4 on 110R rootstocks for the younger vines and St. George for the older vines. The trellised vines are irrigated once or twice per growing season while the older vines are dry-farmed. Yields on the vineyard are between 1.5 and 2 tons per acre. Damaged vines are replaced using massal selection of the To-Kalon clone.

The grapes are sold exclusively to Robert Mondavi with a small amount held back for production of their MACDONALD label. The grapes that they provide to Mondavi comprise 50% of the raw material for a label called Tokalon and 10 - 15% of the Mondavi Reserve. Mondavi's only involvement with the vineyard is turning up to pick the grapes at harvest time.

The MacDonalds can use grapes from any part of the vineyard for their wine. They tend to pick earlier than most. For example, there is a 1-month gap between the start of harvest at MACDONALD and the start of harvest at Beckstoffer To-Kalon. Graeme picks on taste and seeks out a certain nuttiness in the seed as his trigger.

After harvest, the grapes are transferred to Kongsgaard for creation of the wine. The grapes are destemmed and then placed into a tank for a 5-day cold soak. The grapes are fermented by natural yeasts in stainless steel tanks with pump-over for cap management. After a 35-day maceration, the wines are racked into 100% new, medium/medium-plus-toast French oak (Taransaud, Sylvain) barrels for malolactic fermentation and aging. The barrels are employed primarily for their micro-oxygenation function. The wines are racked once or twice a year to minimize oxidation opportunities.

After the vineyard walk, we went into the offices to taste the 2014 vintage of the MACDONALD wine. The wine tasted was a 2014 vintage. It had been opened two hours prior to the tasting.

Graeme MacDonald, grower/winemaker

According to Graeme, 2014 was the earthquake vintage and the wines had started to shut down to conserve energy. The wine had a perfumed nose along with dark fruit and spice. Light on its feet and perfectly balanced. This was a beautiful wine. I have tasted many To-Kalon wines; and this is competitive. I have tasted many Napa wines; and this is competitive. I kept asking Graeme for seconds. I did not spit.

Production levels for the wine is as follows: 227 cases in 2013; 350 cases in 2014; and 425 cases in 2015.

In summarizing, Graeme said that, from his perspective, under Mondavi, To-Kalon was going towards the Bordeaux model. That is, one Chateau owning many acres and with newly purchased land incorporated into the existing estate with full accreditation. In the current environment, To-Kalon is moving more towards the Burgundian model -- many different owners. In his estimation, the latter approach will help to improve the vineyard overall.

I joined the winery's mailing list.

Graeme is an avid student of Hamilton Crabb and the historic To-Kalon and, to a large extent, he seeks to model the Vineyard according to his perception of the relevant precepts. He farms assiduously and with an eye to the future. He collects and studies artifacts of the To-Kalon historic age and steeps himself in them. He maintains an experimental vineyard on the property, a shoutout to Hamilton Crabb but also as a knowledge and resource bank for future generations.

Hamilton Crabb would recognize the spirit that exists here.

©Wine -- Mise en abyme