Friday, October 20, 2017

Virginia wine: The physical environment

I recently visited a number of Virginia wineries with Frank Morgan (Drink What You Like) and will be reporting on those visits in upcoming posts. Prior to those posts, however, I will attempt to familiarize readers with the physical environment within which the region's grape growers operate. I will begin with the landscape, given its role in shaping the state's climate.

Virginia Landscape
With the exception of alluvium and wind-blown soils, an area's soil is derivative of its underlying rocks. As shown in the charts below, Virginia, as a result of long-term tectonic, orogenic, erosional, sedimentary, and intrusional activity, is divided into five major geologic zones. The first chart describes the formation and characteristics of each zone while the latter identifies the rock types included in each zone as well as its period of deposition/intrusion.


Source: http://www.virginiaplaces.org/geology/rocksdui4.html

Virginia Climate
Climate, according to Dr. Tony Wolf (Lecturer and Viticulturist, Virginia Tech) and John D. Boyer, is the average course of weather in a region over an extended period as measured by temperature, precipitation, and wind speed, among other variables (Vineyard Site Selection, Virginia Cooperative Extension).  Weather is itself defined as the state of the atmosphere at a specific point in time using the same variables as referenced in the climate definition above.  The climate of a grape-growing region will determine, to a large extent -- and all things being equal -- both the grape varieties that can be grown and the styles of wine that can be produced. The climatic requirements for successful viticulture include: a growing season long enough to mature both the fruit and vegetative aspects of the plant; production of sufficient carbohydrates to ripen the fruit as well as to maintain future productive potential; and an adequate supply of water.

Virginia's climate is officially described as humid subtropical but, in reality, it has one of the most complex climates in the US. This complexity is reflected by the fact that the state is divided into five climate zones (The figure below actually shows six zones because it breaks Piedmont into eastern and western portions).

VA climate zones: 1 - Tidewater; 2 and 3 - Piedmont;
4 - Northern; 5 - Central Mountain; and 6 - Southwestern Mountain
 (Source: http://virginiaplaces.org/climate/)
According to the University of Virginia Climatology Office, "Virginia's climate results from global-scale weather patterns that are modified by the diverse landscape of the Commonwealth." The following two charts show the manner in which these global-scale weather patterns are modified within the Commonwealth. The first chart shows two temperature modification events. The first is associated with winter storms. These storms work from west to east across the state and turn northeast when they encounter the Gulf Stream. Moisture-laden air from these storms are then blown onto land from the east and northeast, with most of the rain ending up on the eastern slopes and foothills of the Blue Ridge Mountains.

The second event is the classic rain-shadow effect where winds from the west encounter the Appalachian Mountains and dumps moisture on the western slopes of that range as they climb while eastern winds encounter the Blue Ridge Mountains and act accordingly. As shown in the figure, the regions between those mountains are the driest in the state.

Derived from climate.virginia.edu
The water falling on the state is drained off by an extensive riverine system. The workings of this third climate modifier is shown in the figure below.

Acording to Frank Law of Linden Vineyards, Virginia is one of the wettest viticultural regions on the planet. The chart below shows the trend of VA average annual precipitation between 1895 and 2010 and the trend is towards increasing levels statewide. The table below the chart shows the distribution of that precipitation by climate zone.

Trend of VA average annual precipitation, 1895 - 2010
(Source: http://virginiaplaces.org/climate/)

Climate Zone Annual Average Rainfall (inches) January Average Temperature (F) July Average Temperature (F)
Tidewater
41.32
35 - 48 71 - 85
Piedmont
43.37
27 - 47 68 - 88
Northern Virginia
38.29
19 - 42 61 - 86
Western Mountain
40.74
27 - 45 65 - 87
Southwestern Mountain
47.33
24 - 44 60 - 85

As shown in the table above, the average annual rainfall in Virginia ranges between 38.29 and 47.33 inches per year. Contrast this with Napa which receives an average of 20.39 inches, less than half of the rain that Virginia receives. The problem with that much water is that it requires the right type of soil and slope in order to allow proper drainage of the vineyard. Some grape varieties do not like wet soils while too much water does not allow for stressing of the vines, a key requirement in growing high-quality red wine grapes.

In a May 2012 interview with Dr. Bruce Zoecklein, then Professor of Enology at Virginia Tech (and former State Enologist), he told me that Virginia winemakers had to deal with late frosts, drought, high humidity, and tropical storms in the fall and that they needed to continue working to understand these phenomena and then to incorporate their learnings into their viticultural processes.

Virginia Wine Regions
The Virginia Wine Board Marketing Office (VWBMO) provides a map which divides the state into various wine regions and then indicated American Viticultural Areas (AVAs) within those regions. I used such a map as the basis for a graphical presentation of the characteristics of each region (see below).


During the compilation of chart, I became curious as to the genesis of the wine region map and pursued answers along a number of paths. Frank Morgan was finally able to get me a response from Annette Ringwood Boyd of VWBMO which stated that the regions were determined by Virginia Tourism and, when VWBMO started 10 years ago, they "used these so that there would be continuity in how people were talking about Virginia regionally." According to Annette:
As they have added regions, we have mimicked them to continue that seamless presentation of Virginia. One of the strong arguments in support of this strategy is that 60% or more of VA wineries are not in AVAs ... In addition, in 2009 or 2010 we added Virginia AVAs to begin to add wine specific regions to our map. To date this is still imperfect, but long term, this is how we would like for the regions of Virginia to be defined. Until the AVAs are more inclusive, we will use the VTC regions of Virginia.
In other words, the Virginia wine regions, as currently configured, is a marketing contrivance with no undergirding viticultural rationale. While this will work for a tourist-based wine economy, it will force us to continue to look to individual wineries to determine high-quality wines because comparisons within and across regions (outside of the AVAs) are essentially meaningless.

©Wine -- Mise en abyme

Wednesday, October 11, 2017

Crossflow filtration and the Barboursville Vineyards (Barboursville, VA) experience: A conversation with Luca Paschina, General Manager-Winemaker

Winemakers are largely divided between those who filter their wines and those who do not. Those who eschew filtration are concerned that the practice can strip out aroma and flavor molecules, thus rendering the finished product less-than-optimal. In his argument against traditional filtration, Clark Smith, author of postmodern winemaking, states thusly:
The focus of postmodern philosophy is the creation and preservation of beneficial macromolecular structure. This structure manifests in wine as colloidal particles sometimes nearly as large as a bacterial cell. The benefits of good structure -- profundity, aromatic integration, and graceful longevity -- appear to be lost in sterile filtration, despite the fact that no tannin material may be retained by the filter. While this lack of residue has convinced some of my colleagues that filtration cannot be harmful to wine structure, I do not concur. My hypothesis is that the action of tight filtration somehow disrupts rather than removes structure.
In a January 2003 article, Smith  described a class of filtration systems which he called the Tangential Flow Family of Filtration. This family is shown in the table below, classified based on the molecular weight of particles that pass through the pores.

Tangential Flow Filtration

Filtration SystemApplicationMolecular Weight Range (Daltons)
Crossflow Clarification

200,000 - 500,000
Ultrafiltration

1000 - 200,000

Tannin and Browning Removal10,000 - 200,000

Protein Removal10,000 - 40,000

Decolorization1,000 - 5,000
Nanofiltration

200 - 1000
Reverse Osmosis

50 - 200
Source: Clark Smith, The Crossflow Manifesto, Wine Business, January 2003.

According to Smith, the idea of tangential flow filters developed in the 1960s. One of the major problems with sterile filtration is the fouling of the membrane which occurs when tight pore sizes are used. This fouling prevents the passage of material through the pores. The effective limit of traditional filtration is 0.1µ. Tangential flow filters use the scrubbing action of the flow across the surface of the membrane to keep it clean thus allowing the utilization of ever-smaller pore sizes.

All of the systems mentioned in the table employ the strategy of pumping the wine across the membrane at high velocity. As the wine flows across the membrane it continually scrubs the surface, removing fouling material. The majority of the feed stream does not pass through the filter but is retained upstream and returned to the tank. This stream, called the retentate, contains all of the high-molecular-weight components. The low-molecular-weight material that passes through the filter is called the permeate. A comparison of traditional (dead-end) versus tangential filtration is shown in the figure below.

Dead-end versus tangential-flow filtration
(Source: cleanflowfilter.nl)

The Holy Grail of tangential filtrations, according to Smith, "is to be able to clarify wine without harming its structure, and crossflow clarification ... continues to gain steam." In his opinion, the technology works well for unstructured whites, "where a little tannin and color stripping is a good thing, but can prove disastrous for structured reds."

I now turn to my discussion of crossflow with Luca Paschina of Barboursville, a follow-up on a wide-ranging discussion of the estate and its wines. As stated above, Smith has some problem with crossflow filtration and I wanted to see whether his views were being validated at Barboursville.

Luca first became aware of crossflow technology around the year 2000 and was immediately impressed. Barboursville first employed the Bucher-produced system in 2004 in an attempt to clarify its wines in a one-step process. Prior to its implementation of crossflow, the winery was going through at least two levels of filtration and wasting a lot of time and product. The process employed for filtration prior to the acquisition of the crossflow technology was diatomaceous earth (DE) and different levels of pad porosity, staples of the dead-end approach. The issues associated with this approach are catalogued below.


In addition to the one-and-done aspect of crossflow, Barboursville also uses it to remove yeast and bacteria in white wines (thus avoiding the potential of malolactic or yeast fermentation of residual sugar in the bottle) and in reds to avoid Brett bloom in the bottle.

The technology is used on white wines after stainless steel aging on lees, allowing for filtering of the fine lees. These wines are filtered the day before bottling. Red wines are transferred from barrels to tank and then filtered the day after (or later if necessary). Crossflow filtration is applied to every wine once per week between mid-January and late July.

Barboursville purchased its crossflow equipment and paid it off over 5 years. The technology is easy to use but requires an operator with an attention to detail and the ability to follow procedures. The winery is very satisfied with the equipment and the associated process. Staff has adapted positively to the implementation of the product.

In terms of additional advantages, Luca can time his bottling schedule with more versatility (such as filtering today and bottling tomorrow), with no surprises arising from filtration difficulties.

In closing, Luca mentioned that he had initially been skeptical of the product but after seeing how the wines were aging gracefully, he is now a firm believer in the technology.

My conclusion: Luca is using crossflow in an effective and traditional manner (that is, replacement for a DE system) and is currently very satisfied. None of the Clark Smith concerns are evident here.


©Wine -- Mise en abyme

Sunday, October 1, 2017

Esca grapevine trunk disease (GTD) and the role of the Guyot-Poussard pruning system in combating it

During my recent visit to Tenuta di Trinoro, I discovered that the estate had an Esca problem and was employing a pruning system called Guyot-Poussard (G-P) to combat it. I was unfamiliar with G-P so I did some research after my visit with the intent of (i) gaining an understanding and (ii) writing a blog post on the topic.

My good intentions were derailed by a flurry of writings on the Barolo zone. That is, until my visit to Barboursville Vineyards (Barboursville, VA) where, in discussions with GM-Winemaker Luca Paschina, he also mentioned that he was battling Esca and his staff was undergoing training in order to implement the G-P system of the Italian duo Simonit and Sirch. That was a sign. I had to write this blog post. And I had to write it now.

First some background on Esca.

Esca
Grapevine pruning, arguably one of the most important viticultural practices, is employed during the vine's dormant phase and, when done properly, structures the plant such that there is balance between vegetative and reproductive growth. It is generally held that a balanced vine will allow for adequate yields and good quality fruit, assuming no deficiency in the other grape-growing parameters.

Two examples of pruning systems
(Source: pinterest.com)
One of the characteristics of traditional pruning systems is numerous large pruning wounds in the grapevine trunk with the potential for (i) intrusion of desiccated material into the interior of the trunk -- and the interruption of sap flow therein -- and (ii) serving as the infection pathway for grapevine trunk disease (GTD) fungi (Infowine).

Esca is one of the most feared of these GTDs. According to wineterroirs.com (Experimental cure of Esca in the Loire), this disease was known in ancient times but has had an alarming resurgence, especially after the banning of the carcinogen Arsenite which had been used to keep it under control. According to Jane Anson, vineyards across Europe has been losing 10 - 20% of their vines to Esca. But the disease is not limited to Europe, as evidenced by the fact that the Esca-fighting duo Siminot and Sirch have 130 customers across the world.

Esca is caused by several different fungi to include Phaeoacremonium aleophilium, Phaeomoniella chlamydospora, and Formitiporia mediterranea. Symptoms appear on mature grapevines in vineyards (Úrbanz-Torres, et al.):
  • First, symptoms appear as dark red (red cultivars) or yellow (white cultivars) stripes on leaves. These eventually die and become necrotic.
  • As the disease progresses, it causes:
    • Gray to dark-brown speckling of berries, known as "black measles"
    • Sudden wilting of the vines, including shriveling of the fruit that normally occurs in summer and is known as "vine apoplexy"
    • A dieback of the entire grapevine.
"Esca vascular symptoms include primarily a white rot characterized by a yellowish spongy mass of wood, usually in the center of the trunk and/or cordons, which can be observed alone or along with dark-brown to black spots in the xylem vessels (Úrbanz-Torres, et al.). Examples of Esca symptoms are shown in the figures below.

Leaf "burning" associated with Esca
Source: http://www.ipm.msu.edu/

Wood rot associated with Esca
Source: http://www.ipm.msu.edu/

Esca-infected berries speckled with measles
Source: http://www.ipm.msu.edu/
Guyot-Poussard Training System
The principle behind the G-P pruning system (or soft pruning, as it is called in some circles) is simple: If pruning wounds are a gateway for pathogen entry into the vine, then let us seek to reduce the number and severity of those wounds. The hypothesis is that the probability of new infections would decline with a reduction in the number and size of pruning wounds.

The soft-pruning method was adopted by Lafon from a training system used in France in the early 20th century and eventually renamed Guyot-Poussard. It has been further refined and evangelized by the Italian duo of Simonit and Sirch who have traveled around the world preaching the benefits of the approach and who train practitioners of the system at their school in Italy.

The system uses small cuts in the upper portions of the cordon to promote continuous horizontal development of adjacent perennial spurs. The small cuts reduce the size of wound desiccation, minimizes the inward-facing size of the desiccation, and, through their placement on the upper part of the structure, leaves unobstructed channels at the lower part of the established structure. The system structure is depicted in the figure below.

Illustration of the Guyot-Poussard pruning system.
Note the pruning cuts st the top of the cordon
allowing the free flow of sap along the bottom
portion of the cordon (Source:marceaubourdarias.fr)
According to Infowine, this system:
  • Reduces the probability of new GTD infections
  • Promotes more homogenous development of phenological stages
  • Promotes more balanced vegetative growth and more balanced ripening.
A 2016 study of the system as applied in a German vineyard has shown that:
  • Activities such as shoot removal are more extensive and important in maintenance of the training system
  • Leaf removal at flowering and fruit set requires less manpower
  • A higher amount of work is required in the early years
    • G-P pruning 37.7 hours/ha while traditional takes about 23 hours/ha
  • Transition from a traditional to a G-P pruning system will take several years
    • G-P a demanding pruning method and requires significant training before implementation.
According to Bowman, Simonit and Sirch assert that their approach will "double the life of a vineyard and dramatically reduce the incidence of grapevine trunk diseases." Bowman goes on to say that there is no scientific evidence as regards claims about sap flow but that a 2006 study by Geoffrion and Renaudin showed a 50% reduction in Esca-affected vines in G-P-pruned vines when compared to traditional Guyot-pruned vines.

G-P a la Simonit and Sirich has been implemented in a number of high-profile vineyards to include Domaine Leroy, Ornellaia, Chateau Latour, Haut-Bailly, and Louis Roederer. I have previously mentioned Tenuta du Trinoro and Barboursville Vineyards. According to Delbecque, 60% of the producers in the Sancerrois vineyard have trained their employees in this method while 80% have at least one person competent in this approach.

Adoption levels will only increase as we go forward.

Bibliography
Jane Anson, Anson on Thursday: The Prada of Vineyard Pruning, Decanter, 12/10/2015.
Sam Bowman, Pruning: The right cuts to improve vine health and longevity, Grapevine and Winemakers, winetitles.com.au.
Xavier Delbecque, The Guyot-Poussard has the wind in its sails, RéussirVigne, October 29, 2015.
Antonio Graniti, et al., Esca of Grapevine: A Disease Complex or a Complex of Diseases, Phytopathologia, 39(1), September 2006.
Infowine, Technical Data Sheet: Pruning with regard to sap flux, infowine.com.
C. Mutawilla, et al., An overview of grapevine pruning wound protection in South Africa, June 2011, wineland.co.za.
Jan van Niekerk, et al., Susceptibility of grapevine pruning wounds to trunk pathogen infections, wineland.co.za.
J.R. Úrbaz-Torres, et al., Grapevine Trunk Diseases in British Columbia: Incidence and Characterization of the Fungal Pathogens Associated with Esca and Petri Diseases of Grapevine, Plant Disease, 98(4), April 2014.

©Wine -- Mise en abyme

Tuesday, September 26, 2017

Soils of the Barolo Zone

In order to provide a full context for for the discussion of the soils of the Barolo zone, I initially discussed the formation of the basement rocks, then followed that up with posts on the Tertiary Piedmont Basin, with one post each devoted to the Oligocene - Miocene deposit sequence and the Messinian Salinity Crisis and its deposits. This post on the soils of the Barolo Zone culminates the series.

Marco Giardino, Associate Professor of Applied Geomorphology at the University of Turin, is quoted in Kerin O'Keefe's Barolo and Barbaresco thusly: "About five million years ago, strong seismic activity beneath the Langhe Basin ... thrust the submerged land upwards, causing the trapped water to escape and forming the Langhe hills."

These hills are, according to Dr. Giardino, cuestas (ridges formed by tilted sedimentary rock) and, when they were initially formed, eroded such that newer layers moved to the lower parts of the slopes.These hills were subjected to further erosion when the Tanaro River changed from a northerly to an easterly course 60,000 years ago.

According to Kerin, the soils of the Langhe as a whole is comprised of "marine sediments characterized by a substratum of alternating layers of marls and sandstones." In her conversations with Ferdinando Vignolo-Lutati, he described the soils according to the sequences mentioned in a previous post. Those soils are presented in Table 1 below and the geologic formation associated with the region in Table 2. These data are summarized in the figure immediately following the tables.

Table 1. Barolo Zone soil characteristics (Source: Vignolo-Lutati quoted in Barolo and Barbaresco)
Soil Type Characteristics Location
Serravallian Alternating layers of beds of sand and sandstone layered with marls and sandy marls Almost all of Castiglione Falletto, Monforte d’Alba, Serralunga d’Alba, parts of Barolo and Grignano

Generally gray or yellowish sporadically interspersed with layers of bluish gray marls

Tortonian Principally gray and bluish marls Much of Barolo, small portion of Castiglione Falletto, most of La Morra and Verduno
Messinian Clays mixed with very fine sands  with concentrated calcareous content Parts of Verduno and La Morra

Table 2. Geologic soil formations (Source: Barolo and Barbaresco)
Formation Period Characteristics Location
Lequio Serravalian and Tortonian Silty marls comprised of clay, calcium carbonate and sandstone; ranges from light yellow, almost white, tending to gray Predominantly in Serralunga d’Alba and parts of Monforte d’Alba
Sant’Agata Fossili Marls Tortonian (predominantly) and Messinian (partly) Mainly calcareous clay and bluish-gray marls Villages of Barolo and La Morra
Arenarie di Diano d’Alba Serravalian and Tortonian Particularly rich in sand, especially in the subsoils Primarily in parts of Castiglione Falletto


In comparative terms, the Serravallian soils are seen to be richer in iron content than the Tortonian soils which are seen as richer in magnesium oxide and manganese and, with its calcareous marls, as being more fertile and compact than its counterpart.

©Wine -- Mise en abyme

Thursday, September 21, 2017

The Langhe Hills Landscape: The Messinian Salinity Crisis and the Tertiary Piedmont Basin

My previous post treated the Tertiary Piedmont Basin succession through the Tortonian. In this post I treat the sedimentation occurring during the Messinian period.

The Tethys Ocean separated Africa and Europe during the Jurassic and Cretaceous periods but was mostly eliminated as a result of the collision of the continents. Elements of this ocean survive today as the Mediterranean, Black, Caspian, and Aral Seas.
The Mediterranean Sea maintained its connection to the Atlantic and Indo-Pacific Oceans until early in the Miocene when it was reduced with the joining of the two continents along the Middle East front around 14 million years ago (mya). This joining of the two continents began a gradual change to a more arid Mediterranean climate.

The Mediterranean Sea connection to the Atlantic Ocean was maintained through various avenues (see figure below) until the closure of the Rifean Corridor in the early Messinian.


The closure of the Atlantic access precipitated a rapid environmental and climatic change driven by high evaporation rates in the Mediterranean Sea and the inability of riverine sources to replenish the water loss. This event is generally referred to as the Messinian Salinity Crisis and a rough timeline is as follows:

·       5.96 mya – Closure of the Rifean Corridor and partial dessication of the Red Sea
·       5.8 mya – Mediterranean almost dries out. Massive dessication leaves a deep, dry basin 3 to 5 km below sea level with a few hyper-saline pockets
·       5.5 mya – Less dry climatic conditions ensue resulting in more fresh water from the rivers. This fresh water progressively fills the basins and dilutes hyper-saline pockets into larger pockets of brackish water
·       5.33 mya – Zanclean flood. Strait of Gibraltar opens up, quickly filling the Mediterranean with water from the Atlantic Ocean. The end of the crisis.
As described in Progeo Piemonte (Climate variability and past environmental changes: lessons from the Messinian record of the Tertiary Piemonte Basin), “In less than a million years, deep sea sediments are replaced by shallow sea deposits, continental deposits, lacustrine sediments and eventually deep sea sediments.”
According to Nesteroff (The Sedimentary History of the Mediterranean during the Neocene), all of the Messinian deposits they encountered during their drilling explorations in the region “proved to be evaporitic species comprised of dolomitic marls interbedded with massive gypsum, anhydrite and halite.” On land, they found that, in the same period, The Tortonian blue marls were suddenly replaced by either evaporitic series or by lacustrine and continental deposits. The evaporitic deposits are primarily found in the deepest part of the sea but some fragments are found on margins that have been tectonically uplifted.
According to Progeo Piemonte, Messinian age rocks present in the Langhe describe a chronological sequence of the events associated with the Messinian Salinity Crisis:
·       Marls and Mudstones – rocks derived from deep sea sediments. These rocks record the alternation between a warm and humid climate and a cooler, less-humid one. Microfossils in the rock point to the exact moment when the Mediterranean weas cut off from the Atlantic.
·       Gypsum selenite and laminate – These minerals were formed in water with high salinity and point to an increased evaporation linked to the isolation of the Mediterranean Sea.
·       Sandstones and mudstones – Sediments deposited on the continent in low-salinity waters, rich in fossil vertebrate remains and shells of lacustrine molluscs. These remains testify to a savannah environment with temporary pools of fresh water.
·       Calcareous marl – These rocks tell the story of a re-established full connection between the Atlantic and the Mediterranean. These rocks are rich in marine planktonic microfossils recording a deep (around 800 m) marine basin.
·       Erosion surface – This surface describes an event of rapid dismantling of sediments caused by compressive tectonic forces.


©Wine -- Mise en abyme

Monday, September 18, 2017

Formation of the Langhe Hills landscape: The Tertiary Piedmont Basin

At the "end" of the Alpine orogeny, the area that is now the Langhe Hills did not exist in its current form; rather, it was a basin that rested beneath a remnant of the Tethys Sea. This basin -- the Tertiary Piedmont Basin (TPB) -- eventually became the repository for a sedimentary succession -- measuring 3000 sq km -- located at the junction between the southern section of the western Alps and the western termination of the northern Apennines (Mutti, et al., The Tertiary Piedmont Basin) and resting on wedges of both orogens. According to Mutti, et al., the basin rests on a segment of the wedge formed after the Alpine collosional event and was affected by the the growth of the Apennic orogenic wedge from the Oligocene on. Figure 1 below shows the TPB in relation to the major geologic structures of Northern Italy.

Figure 1. Structural sketch map of Northern Italy.
Source: Festa &Codegone, Geological Map of the 
External Ligurian Units ..., Journal of Maps 9, 2013.
The TPB is divided into three sectors -- western (Langhe). central, and eastern -- by the Celle-Sandia and Sestria-Voltaggio fault lines. The sedimentary succession, and underlying basement rocks, are present in all three sectors, as shown in Figure 2A below.

Figure 2: A - Deposits in the basin (Source: The Tertiary Piedmont
Basin, Mufti, et al); B - Age ranges in the Stages of the Miocene
 (Source: Wikipedia); C - Composition and depths of Oligocene
and Miocene deposits (Source: Mufti, et al)

Basement
The western sector basement rocks are Brianconnais units -- slices of European crust with a low-grade metamorphic imprint.

The central sector basement rock is of the Voltri Group, slices of oceanic suites composed of ophiolites (small pieces of oceanic crust that have been attached to the continent) and their sedimentary cover metamorphosed at high-pressure - low-temperature. This structure is generally credited with halting the eastern thrust of the Alps. The Sestri-Voltaggio line is the eastern boundary of the Voltri Group.

The eastern sector basement is comprised of Ligurian units, slices of oceanic suites composed of ophiolites and their sedimentary cover metamorphosed at low- to very-low-grade conditions.

Sedimentary Succession: Mid-Oligocene to Miocene
The TPB sedimentary succession began in the mid-Oligocene and continued through the Miocene. Figure 2A shows the population of sedimentations by geographic era while Figure 2C shows the types and extent of sedimentation exclusive of the Messinian period. The deposits through the Tortonian are predominantly terrigenous in natute -- that is, originating from land -- and are primarily sandstones and mudstones. At its deepest points the succession records a thickness of 6000 m (Mutti, et al.).

As the soils of note in the Barolo Zone derivs mainly from upper layers of the succession, we will confine the discourse in this post to those layers. Mutti, et al., suggest that the depositional settings evolved as follows:
  • Western sector troughs infilled with mixed terrigenous systems delta-fed from the Western Alps (Cortemalia and Lequio Units)
  • A shallow-marine domain, primarily consisting of southerly fed delta systems (Cessole and Serravelle Units) developed in the central and eastern sectors of the basin
  • A progressive uplift of the eastern and central sectors leading to the final infill of the basin with widespread southerly derived deltaic strata (Serravelle Unit)
  • During the Tortonian, these deltaic sediments experience a sudden regional drowning resulting in the deposition of progressively deeper-water and finer-grained strata (Sant'Agata Fossili Marl) and, eventually, chaotic deposits, indicating a tectonically steepened slope environment
  • These finer-grained slope strata encase re-sedimented coarse-grained and channelized bodies (Vargo Units) which are overlain by mudstones that grade upward to euxinic (black carbon-rich) shales
  • The latter are overlain by Messinian evaporites (not shown in Figure 2C and to be discussed in a later post)
The closure of the Straits of Gibraltar led to the Messinian Unconformity signaling the end of the Oligocene-to-Miocene succession. I will cover the Messinian Salinity Crisis in a follow-up post.

©Wine -- Mise en abyme

Wednesday, September 6, 2017

Tradition in Barolo: A visit to the Bartolo Mascarello cellar

The furniture and photographs of famous intellectuals, musicians, and artists adorning shelves laden with books were the same. Even the tiny sign embedded in the building's exterior near the door was the same. Although Bartolo Mascarello was no longer physically there, his presence was palpable as his petite daughter and only heir sat at the same desk where he had hand painted unique, prized wine bottle labels. In that small room where her father had welcomed clients for decades, Maria Teresa Mascarello opened the door for me onto her private life, if only a little.
So reads the opening paragraph of Suzanne Hoffman's Labor of Love, the seminal work on the wine family women of Piemeonte. And those were the words that rang in my ears as I prepared to enter into that room for my first visit ever to the estate.

I met Maria Teresa for the first time in June of 2016 at the Piemonte launch of Labor of Love.

Maria Teresa Mascarello and the author
at the June 2016 launch of Labor of Love
That was a special moment for me as I had participated in a Galloni retrospective (1958 - 2010) of the estate's wines just a little over a month earlier. At that meeting I had expressed my desire to visit the estate and she had responded with her card and the assurance that I would be welcome. I took her up on that promise during my mid-May-2017 trip to Piemonte. And now we were here.



My primary contact during the setup of the trip was Alan Emil Manley and this is who I asked for when we arrived. We were early so Maria Teresa's secretary sat us at the tasting table to await his arrival. On his arrival he indicated that Maria Teresa would be joining us shortly but he would be getting us started in the meantime.

History
Bartolo Mascarello was founded by Guilio Mascarello -- grandfather of Maria Teresa -- on January 1, 1920. Both Guilio and his father Bartolomeo were associated with the local grower cooperative but, using a 10,000-lire loan from a cousin, a loan underwritten by his father, Guilio left the coop to launch his own cantina. The business expanded in the 1930s with the acquisition of vineyard plots in Cannubi, San Lorenzo, and Rué. It was during this early period that the estate's guiding principles were enshrined in its practices (A Wine Atlas of the Langhe):
  • Wines made from grapes from a number of vineyards in order to drive consistent quality
  • No vineyard selections
Guilio's son Bartolo joined his father in the business after the end of WWII. Guilio died in 1981 at the age of 86 and Bartolo took over the running of the estate. In Bartolo's days, Mascarello blended vineyards, fermented the grapes together, and allowed the resulting wine to mature slowly. Bartolo died on March 12, 2005 and management passed to his daughter Maria Teresa.

In his preliminary remarks at the previously mentioned Mascarello tasting, Antonio Galloni stated that he expected the first flight -- themed "ready to drink" and including the 1995, 2000, 2003, and 2005 vintages -- to clearly exhibit the generational shift from Bartolo Mascarello to his daughter Maria Theresa. During her tenure, the aging time has been shortened, the winery (and the wine) has been cleaner, and they now have the equipment to do proper de-stemming. Maria Theresa got rid of the old barrels, she procured a modern de-stemmer, and the grapes are ripening such that it is easier to separate the Nebbiolo stem from the grape.

Viticulture
By this time Maria Teresa had arrived and she warmly greeted us. Given our lack of the Italian language, it was agreed that Alan would continue the discourse and cantina tour and Maria Teresa would re-join us when we returned to the tasting room.

Today the estate owns 5 ha of vineyards (distributed over four MGAs) and produces between 32,000 and 35,000 bottles of wine, 50% of which is Barolo. The characteristics of the MGAs in which the Mascarello plots are located are shown in the figure below. The characteristics of the individual plots are shown in the figure following.



The estate, according to Alan, is traditional in both its farming and cellar practices. They try to grow balanced fruit rather than going for "super" concentration. Nebbiolo is a vigorous vine and, as such, requires focused canopy and yield management regimes. In the case of canopy management, its utility as a tool in the battle against the effects of global warming also has to be taken into consideration. The vineyard architecture and cultural practices are illustrated below.


Cellar
As we discussed the elements of the cellar, we walked through areas exhibiting very old bottles of wine as well as examples of Bartolo's well-developed and highly regarded wine labels.



Maria had written an article for Tong Magazine a few years ago in which she described the vineyard and cellar work required to make Barolo in the Mascarello style. I have summarized her writing on the cellar work in the figure below.


The goal, according to Alan, is to make a truly harmonious Barolo. And that task begins with the harvest date: we wait for the skins to tell us when to harvest. Further, there is a strict selection of the grapes that make it into the wine. That selection begins in the vineyard, where imperfect fruit is left on the ground, and continues with a second selection at the sorting table in the cellar.

Fruit from the four plots are mixed in the fermentation vats in a process called "asseblaggio." As the harvest time differs from vineyard to vineyard, recently brought in fruit is added to the mix that is already resident. According to Alan, "the ratios change from year to year as nature gives us different quantities from year to year. What the land gives us becomes our wine. We do not adjust the proportions to keep a constant ratio. For example, in 2012 we had hail only in Rué, and half the fruit was damaged and left on the ground. We simply had less of the Rué fruit in the mix that vintage ..."

The fermentation tanks are fiberglass-lined concrete tanks from the 1940s. The Slavonian oak barrels used in the aging process are changed out every 40 to 50 years. The aging regimes are as follows: Dolcetto and Freisa, 1 year; Barbera and Langhe Nebbiolo, 2 years; and Barolo, 3 years.

Tasting
At the conclusion of the cellar tour we returned to the tasting room to sample the wines. We started with a Barbera 2014. This had been a difficult year with lots of rain. The weather cleared in the last two weeks of September and the first two weeks of October. The best wines of this vintage are excellent. Rose petal, spice, and rusticity on the nose. Good acidity and power.

Alan in the tasting room

Next up was the 2012 Barolo, This is a vintage, according to Alan, that they consider "shy" -- it requires a bit of coaxing. That year was never too hot, never too cool. They had hail in Rué and that is the vineyard that provides structure. Strawberries, honeyed nose, dried flowers, green herbs, sweet talcum powder. Delivers on palate. Fine-grained tannins. Lenghty finish.

Maria Teresa in the tasting room

The final wine tasted was the 2013 Barolo. This was a cool, classic vintage. After 21 days of maceration they terminated skin contact. Alan expects this wine to begin closing down temporarily sometime in the near future. Strawberries and roses. Honeyed nose with a hint of balsamic. Concentrated yet balanced. Lengthy finish. A wine to be aged and for the ages.

Alan and Maria Teresa

As we were going through the wines, Maria Teresa re-iterated the importance of her father's influence in everything that is done on the estate today. This adherence to his teachings is done both to honor him and because it continues to result in excellent wines that appeal to her customers.

Alan was a fount of information and a pleasure to be around if you like diving into the innards of a vat. We truly enjoyed this trip and would like to thank Maria Teresa and Alan for the hospitality and insights.

©Wine -- Mise en abyme

Tuesday, August 29, 2017

Monvigliero, the "Grand Cru" of Barolo's Verduno commune

In my most recent post I wrote about my visit to Comm. B. G. Burlotto and its iconic single-vineyard wine sourced from the Monvigliero cru. This cru is widely held to be the best in Verduno and one of the best in the entire Barolo zone (see, for example, Vittore Alessandria in his Vinous video on the Monvigliero vineyard and Gian Battista Alessandria in his video interview with BBR). In his scheme, Galloni rates this vineyard as Outstanding while Masnaghetti rates it as Three Stars. Renato Ratti did not mention this vineyard in scheme.

As shown in the figure immediately below, Verduno (to the north of the red borderline) is the northernmost of the Barolo sub-zones. Monvigliero is one of its most northern vineyards. Monvigliero is shown at the top of the first map (orange-brown color) and is highlighted within the red border in the satellite map following.

Verduno commune with Monvigliero cru at top center
(orange-brown color).

Rough (red) outline of Monvigliero cru

The River Tanaro runs through the commune and, according to Fabio Alessandria of Comm. G. B. Butlotto,  affects its microclimate. The vineyard is south-facing and has full access to the sun's rays all day. In addition, the soils are white. This combination results in summer warmth but this is mitigated by a cooling breeze that flows along the river valley during the nights. This breeze contributes to a significant diurnal temperature variation, a variation that is important for the characteristics of the wine: perfect maturity of fine, gentle tannins. (IDTT 246, Levi Dalton interview of Fabio). The Monvigliero vineyard is a beneficiary of these conditions.

The characteristics of this cru are shown in the figure below.

Source: Masnaghetti's Barolo MGA

The soil, according to paoloscavino.com, is primarily light-colored limestone mixed with chalky veins. According to Fabio (Vinous video on Monvigliero), the soil is traditional Sant'Agata marls with a mix of 40% silt, 30% limestone, and 30% sand. These white limestone soils drain well and ally with the micro-climate to give considerable finesse to the wines.

The producers plying their trade in the cru are shown below. Known vineyard sizes are Fratelli Alessandria (1.30 ha over three plots), Scavino (0.8340 ha), and Bel Colle (1.35 ha).


Wine Characteristics
According to Fabio, Verduno wines provide perfume, elegance, and finesse, especially from Monvigliero, which is considered the most feminine vineyard in the Barolo area. In the interview with Levi Dalton (IDTT wine 246), Fabio described the Monvigliero as being "lighter and more airy than other Barolos". In my interview with him Fabio described the wines from this cru as having a different quality of tannin in the mouth, a deepness, and a complexity of texture. The Monvigliero, according to Fabio, "exalts brightness and freshness."

Vittore Alessandria sees Monvigliero as producing "Barolo wine that is very fragranced and delicate with a balanced body and with soft tannins." This is "an extremely long-lasting wine which preserves these characteristics through time."

In my tasting of the 2012 Monvigliero at the Burlotto cantina, I described the wine thusly: "The Monvigliero had an almost see-through color; cinnamon, raspberry, strawberry, rhubarb, green herbs, and black olives on the nose; and stems on the palate. Fruit concentration balanced by acid levels. Pure. Will have a long, fruitful life."


©Wine -- Mise en abyme