Nervi’s Molsino, Valferana and Garavoglie vineyards are blessed with perfect conditions for the growing of quality grapes. The three vineyards enjoy ample exposure to sunlight, good ventilation, moderate day temperatures, low night temperatures, limited rainfall and well draining volcanic soil – rich in minerals and clay. This has been known for at least eight centuries as witnessed by rental contracts and transfer deeds from the early 13th century. One such contract from 1231 stipulates that the tenant farmer Peter Burro had to settle his rent in good wine from the Valferana vineyard. Should the landowners Andreas of Quitacho and Hugo of Alice deem the wine not good but merely mediocre, Peter would have to settle his rent in cash. The contract is a testimony of Nervi’s Valferana vineyard producing fine wine of distinct geographic origin already 105 years before Cistercian monks in Burgundy established their first enclosed vineyard at Clos Vougeot and 429 years prior to Arnaud III de Pontac introduced the single vineyard concept to Bordeaux at his estate Haut Brion in 1660.
Rental contract for a vineyard in Valferana from 3rd March 1231 between Peter Burro, Andreas of Quitacho and Hugo of Alice. Witnessed by Lord Adicio, Lord Gabi and Mr de Musis, Notary Public of Gattinara. The word Valle Florana is visible in line 12.
Nervi’s Molsino vineyard in the back and Nervi’s Valferana Fileppo vineyard in front on the right
Nervi’s Molsino vineyard is 13.4 hectares and range from 302 to 414 meters above sea level. It is a south facing natural amphitheatre and considered one of Piedmont’s finest. Podere dei Ginepri – the juniper farm – on the top of the Molsino exhibits spectacular views. On a clear day Milano, the Appenines, Torino, Monviso, Serra d’Ivrea, Biella, Monterosa and Mischabel are all visible. In local dialect the name Molsino means morbido – soft – and appears as Vigna ad Molexinum in deeds from 1471. It was one of the highest prized vineyards in the Gattinara Catasto – tax survey – of 1533.
Nervi’s Valferana vineyard is 5.3 hectares and range from 320 to 370 metres. Nervi’s best parcels are called Valferana Fileppo and are on the south face of a steep free standing hill in the middle of the larger Valferana valley. The vines are between 40 and 10 years old with the majority planted in the mid 1980s. The name appears in deeds as early as 1228 and derives from Valle Florana – the fertile valley – or Valle Ferro – the iron valley.
Nervi’s Garavoglie vineyard is 5.0 hectares and range from 300 to 370 meters above sea level. It straddles a south-west facing promontory next to the Molsino vineyard. It was called Molsinetto – little Molsino – from the 1470s onwards but changed name in 1679 when Nobleman Garavoglie from Turin bought it and vainly renamed it after himself. The vines in the lower parts are between 15 and 90 years old. The upper parts are run jointly by Nervi and the University of Turin and host Italy’s largest research vineyard for North Piedmontese Nebbiolo clones. A total of 5 700 plants derived from 14 ancient Gattinarese Nebbiolo plants grow alongside 2 500 Nebbiolo control plants from Langhe, Valle d’Aosta and Valtellina. Based on plant observations and micro-vinification, The University of Turin and Nervi aim to expand the Nebbiolo family by homologating distinct Gattinara Nebbiolo clones – Spanna – from this research vineyard.
Nervi’s Molsino amphitheatre with Podere dei Ginepri on top, the Garavoglie vineyard on the left and Monte Barone, Monte Rosa and Mischabel behind
Aspect and slope
All Nervi’s vines face either south-east, south or south-west. They capture sunlight from sunrise to sunset. The sunlight provides the energy required for the vine to produce oxygen, starch, sugar, colour, aromas and precursors to aromas. In Nervi’s vineyards the sun provides about two and a half kilowatt-hours of energy per vine, sufficient power to run a normal washing machine, two vacuum cleaners or four hair dryers. The plants absorb sunlight through their leaves and require 1.5-2.5 square meters of canopy to produce a kilogram of high quality Nebbiolo grapes. The energy is required for the vine to transform carbon dioxide (CO2), water (H2O) and minerals into oxygen (O2) and carbohydrates (C6H12O6). The Oxygen transpires into the air from the plant while the carbohydrates serve to maintain the vine, grow leaves and produce fruit. From veraison in early August through to harvest in mid October, a Nebbiolo vine produces carbohydrates akin to 240 grams of sugar per kilogram of grapes. When transformed to wine through diligent fermentation and maceration, this sugar originating from the sun shining on the leaves ends up as wine in the bottle.
The slope is steep and each successive row of vines is planted sufficiently far down the hill to allow the row above unobstructed exposure to the sun. Thus aspect and slope provide ideal ripening conditions for Nebbiolo. Being in one of Italy’s northernmost wine regions, Nervi’s vineyards enjoy longer days and more sunlight than most other Italian vineyards. In the month of June, Gattinara has six hours of daylight more than the Langhe, eight hours more than Tuscany and 18 hours more than our volcanic colleagues on Etna in Sicilly. It means that relative to vineyards in these other vine regions, the vines of Nervi spend a higher portion of each day producing colour, aromas and precursors of aromas for the benefit of making an elegant wine.
Vine rows spaced out to avoid shadow from one row covering the other
Photosynthesis and anthocyanins
The photosynthesis only starts working well at temperatures above 18 degrees Celsius. It reaches maximum efficiency or, in more scientific terms, assimilation of Carbon Dioxide per unit of leaf area, when the temperature is between 25 and 30 degrees Celsius and light intensity is around 1000 µ mol m-2 s-1. Such level of light is about half the light intensity we experience at noon on a clear and sunny day. There is unfortunately no way of compensating shorter or cloudy days with higher light and heat intensity because the photosynthesis’ efficiency rapidly diminishes at temperatures above 33 degrees Celsius and grinds to a halt at temperatures approaching 40 degrees Celsius. Transpiring leaves and grapes are often five degrees Celsius warmer than ambient temperature. Under direct sunlight, dark grapes like Nebbiolo develop hotspots that are up to 15 degrees Celsius warmer than ambient temperature. It means exposed berries may reach temperatures well above 33 degrees Celsius. At such temperatures the photosynthesis shuts down and both leaves and grapes are likely to suffer sunburns. To protect leaves and grapes against UV and blue-green light, the vines develop anthocyanins, a form of grape suntan lotion. The anthocyanins are largely without any aroma but act as anti-oxidants protecting the plants from free radical oxidation, give colour to the wine and play an important role in tannin retention, thus determining the wine’s aging potential. In spite of this marvellous multipurpose sun tan lotion, sunburns do occur. Most prone are grapes in south-west facing vineyards exposed to direct sunlight in the afternoon. The result is wilting, shrivelling, drying, leaf loss, skin browning, development of undesirable aromas and loss of anthocyanins. The only feasible protection is cooling the grapes by sprinkling with water – widely practiced in the new world but completely illegal in Italy and most of Europe – or rely on breeze to provide respite.
Monterosa’s glaciers behind the Nervi Molsino vineyard
Barely 40 kilometres behind Nervi’s vineyards we find Monterosa, Europe’s second highest mountain marking the border between Italy and Switzerland. Holding a quarter of all European peaks above 4 000 meters, the Monterosa massif dominates not only the views from Gattinara to the North but also governs the breeze in Nervi’s vineyards. The 4 634 meter high wall heats quickly after sunrise, causing local air to heat and rise. Before noon a steady thermic breeze starts flowing through the vineyards as cooler air from the Po valley migrates towards the north to fill the resultant void. The breeze helps cool both grapes and leaves. It also brings humidity from the nearby rice fields. This ensures sufficient, albeit rarely excessive water for the vines. In the peak growing season, Gattinara experiences 60-70 per cent. more rain than the Nebbiolo vineyards in the Langhe region. But Botrytis is rarely a problem as the grapes are quickly dried by the caressing breeze.
At night the thermic wind reverses. Cold air from Monterosa’s glaciers drop down the foothills and flow through the vineyard. Low night temperatures contribute to an elegant wine because the night time decomposition of aromas and acidity inside the grape is much slower than in wine regions with higher night temperatures. In July, night temperatures in Nervi’s vineyards are two to three degrees Celsius lower than in Southern Piedmont, Veneto and Tuscany and six to seven degrees lower than in Puglia and Sicily. Therefore, relative to those regions, grapes from Molsino, Valferana and Garavoglie tend to develop more acidity, aromas and precursors of aromas and less sugars. This translates into a crisp and elegant wine rich in aromas relative to alcohol content.
Vine roots extract mineral nutrients from the soil water. Unless the soil is dry and highly compact, Calcium, Sulfur, Sodium, Nitrogen-nitrate, Boron and Magnesium will normally be abundant and flow towards the roots. The other soil minerals, Potassium, Phosphorus, Copper, Iron, Zinc and Manganese have to be present in a sufficient and permanent level close to the roots. These minerals are typically more prevalent in deeper soil layers. Therefore younger vines are more prone to deficiency because of their shallow roots. Irrigation, particularly drip irrigation, reduces the need for roots to go deep and will often exacerbate deficiencies. An example is provided by California where deficiencies of Zinc, Boron and Iron are wide spread and often sought mitigated through foliar sprays and mineral fertilizers. But rectifying deficiencies of soil minerals is not easy and the margins are unforgiving. A vine needs at least 0.4 particles per million Boron to produce grapes but will wither and die if the level increases to 1.0 particles per million. That means the plant needs 0.00004 per cent. Boron to stay healthy while an increase to 0.0001 per cent. Boron is lethal!
Young Spanna clones planted in volcanic gravel in Nervi’s Molsino vineyard
A porous well draining soil ensures that the vines suffer a slight water deficiency. This forces the vine roots to penetrate deeply in their quest for water. It also prevents the grapes from accumulating excessive water content. Deep root penetration is beneficial for the vine as certain mineral nutrients are more prevalent in the deeper soil layers. Too much water relative to sugars, anthocyanins, aromas and precursors to aromas in the grape translate into a wine low in alcohol, colour and aromas. This is never a problem in Nervi’s vineyards as the steep slopes and the porous nature of the soil ensures efficient drainage and a healthy water deficiency for the plants.
Gattinara is blessed with an abundance of volcanic gravel, rich in the minerals Iron, Zinc, Magnesium and Manganese. Coincidentally these are also the minerals required for vines to produce excellent grapes for the making of fine wine. Gattinara’s volcanic gravel is the remnants of the Valsesian Supervulcano. With a crater 13 kilometres across, the volcano spewed out lava for ten million years before it collapsed about 280 million years ago. The magma which subsequently solidified in the conduits 25 kilometres below ground came to the surface about 60 million years ago when Africa hit Europe to create the Monterosa massif and tilt the volcano’s conduits 90 degrees. The resulting fault lines offer a rare opportunity to study what happens deep down below a volcano. Valsesia and Gattinara is therefore a Unesco International Geopark. The fault lines also offer an explanation to the extraordinary mineral content of Molsino, Garavoglie and particularly Valferana’s soil. The magma solidified as rock in the conduits of the volcano, had extraordinary high mineral content, particularly Silicon, Iron, Manganese, and Zinc. Through erosion parts of this volcanic bedrock have turned into mineral rich volcanic gravel, providing ample nutrition for Nervi’s vines.
Clay as conductor
Most of the soil minerals are absorbed as ions by the plant. They are positively charged elements and attach themselves to negatively charged particles. The higher the density of negatively charged particles in the soil, the higher the capacity to lead positively charged mineral nutrients towards and into the roots. That capacity is lowest in coarse sand, somewhat higher in fine sand and silt and at its maximum in clay. Clay particles are less than one thousandth the size of a coarse sand particle. The aggregate surface of one gram of coarse sand particles is about 0.01 square meter per gram while the equivalent for clay ranges from 100 to 750 square meters per gram. This vastly expanded surface area provides an abundance of negatively charged particles that conduct the positively charged soil minerals into the roots of the vines. Nervi’s Molsino and Valferana are unique among Nebbiolo producing vineyards as they exhibit both high level of mineral nutrients thanks to the volcanic gravel and an extraordinary mobility of these minerals into the vine and grapes thanks to high levels of clay.
Upper Molsino in fall
What do the minerals actually do?
To make an optimal grape for wine making, the vine requires a number of soil minerals. The most important are Potassium (K), Phosphorus (P), Magnesium (Mg), Sulfur (S), Zinc (ZN), Boron (B), Iron (Fe) and Manganese (Mn).
- Vines require Potassium to form sugars – mainly fructose, glucose, sucrose and pectin – for development of starch, for cell division, for synthesis of proteins and to regulate the other mineral nutrients in the plant. Between one and four per cent. of the plant’s dry weight is made up of Potassium. The mineral is highly soluble and will leach away in light soils. The resulting deficiency manifests itself in leaves turning beige and brown along the edges.
- Phosphorus is required to generate the backbone of DNA molecules and essential to the vine’s energy provisioning through the interchange between ADP (adenosine diphosphate) and ATP (adenosine triphosphate).
- A Magnesium ion sits at the centre of each chlorophyll molecule and is essential to the photosynthesis. Vines deficient in Magnesium are immediately recognizable from the basal leaves turning white along the edges (chlorosis) for want of the green chlorophyll pigment. Magnesium also activates many of the enzymes required for the vine to grow.
- Sulfur’s main role is the formation of amino acids required for protein synthesis and formation of root nodes.
- Zinc is a critical component of auxins, a set of chemicals required to develop starch and chloroplasts. Without Zinc the vine will not develop pollen, leafs, shoots or berries.