Characterization of the Oxygen Transmission. Qvevri, Concrete, Stonewear

Today, there is a trend in enology promoting a return to the use of old natural materials for the manufacture of storage and maturation wine tanks. One of the most sought-after characteristics of these materials is their permeability to oxygen from the atmosphere to improve wines without this being a harmful process. The reference performance in wine aging is, without doubt, the oak barrel for its ability to oxidize wines in a controlled way, thus improving them. It would be possible to mature wines in containers in which the use of wood is not obligatory, as opposed to aging in oak barrels or foudres. This work presents the results of oxygen permeation analysis under test conditions typical of a tank containing wine, using materials, such as concrete and granite. The oxygen permeability of the materials tested was very diverse, typical of natural materials. The results showed that earthenware presents an excessive permeability, not only to atmospheric oxygen, but also to liquids and needs treatment before being used in liquid containers. Claystone and concrete can be impermeable to liquids, but maintain permeability to atmospheric oxygen—making them candidates for use in permeable tanks for wine maturation. Finally, granite has some very interesting characteristics, though thickness control is required when calculating the desired oxygen transmission rate. View Full-Text

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The cone, the sphere, the ellipsoid, the tulip, the truncated pyramid – wine vats come in a bewildering array of shapes these days, but none has made as much of an impact on the 21st-century wine world as the egg.

The cone, the sphere, the ellipsoid, the tulip, the truncated pyramid – wine vats come in a bewildering array of shapes these days, but none has made as much of an impact on the 21st-century wine world as the egg. The advantages of the egg-shaped vessel are several. As carbon dioxide rises through the must during fermentation, the ovoid shape creates a convection current – like a natural pump-over – which facilitates homogeneity of the must and uniform fermentations.

If the wine remains in the egg for maturation, that current continues. Werner Michlits of Meinklang in Austria explains that as heavier molecules in the wine polymerise, they sink to the bottom of the vessel and push lighter ones upwards. This creates a continuous battonage, increasing lees contact and enhancing the wine’s texture. Benefiting from the flavour neutrality and micro-oxygenating properties of the materials they are made of (concrete, clay, high-vitrification ceramics), eggs also promote fruit purity and aromatics. https://imbibe.com/news/its-all-ova-now-the-rise-of-egg-fermenters/

While concrete is by far the most common material for egg-shaped wine vessels, it’s not the only one. In 2012 an American company, Flextank, launched the first egg-shaped vessels made from durable oxygen-permeable polyethylene. They’re relatively cheap – the Orion 20hl egg tank costs $2,525 (£2,014), compared to a Nomblot 17hl egg that costs €6,100 (£5,515). Recyclable and easy to clean, Flextanks are built to last up to 20 years – that’s more than double the life of oak barrels.

They also come in heavyweight and lightweight options, which, the manufacturer says, simulate the micro-oxygenation processes of neutral and two-year-old oak barrels, respectively. Slovakian producer Slobodne has reported early positive results from its two Flextanks, which have joined its handsome collection of qvevris and tinajas. If you’re a winery with money to burn, you can also invest in the Rolls-Royce of egg-shaped vats – the Taransaud Ovum.

Launched in 2010, this 20hl vessel is priced at €45,000 (£38,984) and has been snapped up by wineries across the world, including Domaine de Chevalier in Bordeaux, Drappier in Champagne, Biblia Chora in Northern Greece and Tony Bish Wines in Napier, New Zealand. When it comes to wine quality, however, the Taransaud Ovum may not be the last word. The best material for ovoid containers, according to Australian master craftsman Philip Sedgman, is ceramic. Sedgman is an expert in flowform structures – water-flow devices associated with biodynamics. His elegant 675l Magnum 675 ceramic egg, priced at AUD$6,750 (£3,882), was inspired by the ‘Natural Selection Theory’ group of winemakers: Tom Shobbrook, James Erskine, Sam Hughes and Anton Von Klopper.

 

An ancient technique, probably adopted first by the people living in today’s Georgia, namely those to whom recent archaeological discoveries attribute the spread of “Vitis Vinifera” throughout continental Europe.

An ancient technique, probably adopted first by the people living in today’s Georgia, namely those to whom recent archaeological discoveries attribute the spread of “Vitis Vinifera” throughout continental Europe. Several thousand years later, this methodology has been rediscovered and many winemaking realities have launched themselves into this adventure; in fact, this type of container allows micro-oxygenation just like wooden barrels, but unlike the latter, it does not release aromas, allowing the wine to express the varietal characteristics of the grape.

There are many producers who use ceramics, stoneware or other mysterious mixtures for their production of wine jars. I believe that the real Jars or Amphorae, wherever they are made in the world, are those produced in terracotta. The rest are only copies … which, by all means, can work very well, but have little to do with the ancient tradition and the charm of the authentic terracotta vessels. Even the results are quite different, in fact terracotta “breathes” while jars made from ceramics, stoneware or similar, are closer to concrete or steel. Today, terracotta amphorae producers are springing up in America, France, China, etc. I think it’s great that a material like terracotta, which seemed destined to almost disappear has become a protagonist once more!

Five questions for…Leonardo Parisi, producer of terracotta amphorae for wine

Oregon made qvevri

Andrew and Annedria Beckham are the owners of Beckham Estate Vineyards in Sherwood, Oregon, where Andrew is the winemaker. Unique to Beckham Estate Vineyards, Andrew Beckham blends his two passions, wine and art, using Amphorae. Amphorae are terra cotta vessels used as part of an ancient tradition of winemaking in terra cotta vessels, thought to originate in the Republic of Georgia. This is part two of the Beckham oral history interviews. This interview takes place at Union Wine Co. in Tualatin, Oregon where Beckham stores and makes his wine. In this interview, Beckham tells about his experiences using Amphorae. To access more material in this collection, please visit Digital Commons at http://digitalcommons.linfield.edu/ow…. https://www.youtube.com/watch?v=BB1MW2kB3a4

A Comparison of In-Amphorae ( Qvevri ) Winemaking to Barrels/Barriques in Chardonnay Wine

Selected Results

Chemical analysis of the Chardonnay grapes at harvest resulted in the following values: 21.9oBrix sugar content, 7.60g/L titratable acidity, 2.25g/L malic acid, and 3.17 pH.
Only the dry extract and volatile acidity were statistically significantly different between the different wines (though there were some value differences that didn’t quite make it to statistical significance).
The researchers confirmed the higher dry extract in amphorae wines was due to the pomace cap maceration process.
The amphorae wines showed higher volatile acidity, straw color, and perception of tannin compared to the barrel and barrique wines.
Barrel and barrique wines showed higher vanilla flavor than amphorae wines.
Amphorae wines showed lower titratable acidity than the barrel or barrique wines (not statistically significant).
Volatile acidity was higher in barrique wines than barrel wines.
Malolactic fermentation was complete much faster in amphorae wines than barrel or barrique wines.
This again, according to the researchers, might be explained by the pomace cap, since there might have been wild lactic acid bacteria present, thus helping the process along faster than without the extra bacteria.
Lactic acid levels were more or less similar between the three wines at the end of the winemaking process.
Sensory analysis revealed:
Amphorae wines had a “mature scent”, fewer green characteristics, and fewer Chardonnay varietal characteristics. Tannins were “elegant” and the wine had a “pleasing taste” (higher than the barrel or barrique wines). A spicy scent was noted, as well as a lack of vanilla character.
Barrique wines had a lot of vanilla tones, and exhibited strong Chardonnay varietal characteristics. Characteristics noted were “fresh, harmony, and a remarkable woody flavor”. The panelists made a note to possibly blend this wine with the other wines to take the woody/oak characteristics down a notch.
Barrel wines possessed the most Chardonnay varietal characteristics, and were considered to be the most balanced with spice, light oak, and vanilla character in addition to the fruit character. Panelists noted it was “full, balanced, fruity” and had a “persistent flavor”.

Concrete helps to understand terroirs

One of his first steps was to replace stainless steel and wood fermentors with large, tulip-shaped concrete vats for all three wines, which are fermented with wild yeasts.

“With two years of aging in barrel,” says Ruini, “I don’t want to add more wood. Concrete is neutral. Steel has a reducing effect on wine—it’s not the best.”

Are natural winemakers in denial about mousiness?

http://www.themorningclaret.com/2017/are-natural-winemakers-in-denial-about-mousiness/

 

Some interesting ideas about amber wines

Trelab presented a poster about ongoing Qvevri research at the recent Washington Association of Wine Grape Growers annual meeting.

Trelab presented a poster about ongoing Qvevri research at the recent Washington Association of Wine Grape Growers annual meeting.

via The Qvevri Project.

Characterization of Selected Organic and Mineral Components of Qvevri Wines

Characterization of Selected Organic and Mineral Components of Qvevri Wines

via Characterization of Selected Organic and Mineral Components of Qvevri Wines.