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Understanding the veil of flor

On Sunday the 26th of November we had the chance to run a masterclass at Mistral talking about how the veil of flor shapes the character of both unfortified and fortified wines from Jerez. A total of seven wines were poured and divided into 3 different blocks defined by the different stages during the life of the veil.

Let's start from the beginning. The veil of flor is nothing else than a culture of yeasts that cover the surface of the wine creating a film that will protect the wine from getting oxidized.

How is it formed?

There are four groups of yeasts (all of them belonging to the Saccharomyces Cerevisiae family) that are responsible for the creation of the veil: Beticus, Cheresiensis, Montuliensis, and Rouxii.

These yeasts have a high tolerance to alcohol and great fermentative power, in such a way that once the sugars in the must have been consumed they can use the resulting alcohol for the same end. These yeasts also have the property of being able to flocculate due to a mutation in one of their genes. Once the sugars contained in the must start to decrease they join together forming a mesh that traps the particles of carbonic, not only facilitating the union of some cells with others but allowing them to ascend to the surface of the wine.

The yeasts that form the veil of flor go through different phases during their development as it takes a wee while for the veil to cover the surface of the wine completely. Thus, it starts like small dots that, as they join together, create small islands until, finally, they cover the full surface giving birth to what's commonly known as the "tambourine skin", impeding the oxygen from getting in touch with the wine and thus starting what it's called as biological aging.

The nature of the veil of flor

It is right at the surface of the wine where the yeasts find the oxygen that allows them to metabolize other completely different kinds of compounds such as alcohol and glycerin, which are responsible for the sensation of sweetness and density in the wine, so when those yeasts devour these compounds they produce acetaldehydes (etanal) which is a volatile compound that does the contrary effect as it adds a piercing sensation, highlighting the salinity, sapidity, dryness, and bitterness in the resulting wine, and giving us new aromatic nuances in return too.

The vineyards closer to the Atlantic Ocean tend to reward us with a type of flor that's named "the sprinter" because it colonizes the surface of the wine very quickly giving a veil that is quite thick and wrinkled. However, when we talk about those inland vines, the veil of flor can take around 3/4 weeks to be fully formed, and in some cases, those veils are not fully completed, presenting some clear areas where the wine is in touch with the oxygen.

Regarding the soil, where there's a lot of organic matter it means that the vine can root more, having more nutrients will give us a finer and healthier wine where the veil of flor will develop exuberantly and it'll produce less amount of acetaldehyde because the veil it won't be so stressed as when the vine grows in poorer soils with a higher content in chalk. In those cases the resulting veils will be thinner and even incomplete, producing more acetaldehyde.

Also, the optimum conditions for biological aging to develop depend on places where there is a high level of humidity and a temperature that oscillates between 12 and 24 degrees Celsius. That's why the "bodegas" (wine cellars) are built almost as bio-climatic domus. Tall walls favor the ascent of warm air to the ceiling, releasing pressure from overheating the barrels. They're also filled with numerous windows that can be opened to profit on the breezes that are coming from Poniente (West) and Levante (East) capturing its freshness. Last but not least, the floor in these bodegas is made with a kind of clay called albero, which can be watered to increase the levels of humidity if necessary.

The tasting

As you can see, there are a lot of variables involved in the formation of each veil of flor. Right because of this Vera and I found this topic of great relevance when talking about biologically aged wines. When learning about sherry styles we found that they're commonly described under generic patterns and that's not correct. The different Manzanillas and Finos out there are so different from each other precisely because of all those factors mentioned above: the veil of flor, the different kinds of Albarizas, the nature of each vintage, the winds from Poniente and Levante, the humidity & temperature... it was about time to talk about it.

During the first block of the tasting, we focused on unfortified Palominos. Palomino has been a reviled grape for many years, which was accused of being a neutral variety that could not be used for anything other than long aging for the wine to gain some character. The reality is that this neutrality of which Palomino was accused was a direct consequence of the mechanization of the vineyards in Jerez and mass production. Luckily in Jerez, the equation in which the most important factor was the cellar (la bodega) is being reversed, and today the weight falls on giving importance to what's happening in the vineyard again because that is where wine is born.

1. La Hacienda de Doña Francisca, Callejuela, 2021

'Hacienda de Doña Francisca' is a specific small vineyard within Pago Callejuela, on the estuary side of Sanlúcar. The Albariza here is a kind called Tosca Cerrada (lower levels of chalk). The Palomino is fermented in old Manzanilla botas, and the wine is aged on fine lees for 7 months aging under velo de flor. They fill the bota more than usual facilitating only a light coverage of flor, which in combination with the shorter ageing term, emphasises the expression of the Albariza over that of the yeast. It's a vertical, salty, and breezy wine that talks to us about citric skins, golden apples, white fruits, and orchard flowers.

2. Dorada, Bodega Vinifícate, 2021

The grapes are sourced from Pago Mahina, located right at the mouth of the Guadalquivir. This is a bit of an inland Pago that is protected from the direct influence of the Ocean by other mythical hills located in front of it such as Callejuela, El Peral, Martín Miguel... The single vineyard is called 'El Vicario' (imagine if the vicar would not buy the best vineyard at the time) and it is 95 years old. This Palomino made by the Mahara brothers is a wine where the lees are removed after fermentation so they do not have a big impact on the character of the wine. The wine is allowed to undergo malolactic fermentation and, immediately afterward, it is transferred to an amphora where it is aged under a fine veil of flor. It spends a little time in the amphora (around 6 to 9 months) because the grapes from this plot tend more towards oxidation and the Mahara brothers want to avoid these oxidations. This is a fatter Palomino which is dressed in silk, where tension has turned into freshness. With aromas of orange blossom, flat peaches, and saffron. One of the most elegant unfortified Palominos out there.

During the second block, all our efforts focused on showcasing the different stages of biological aging in fortified wines. Here we also spoke about that wonderful and mysterious world which is the criaderas and solera system. Here is when we talked about Fino and Manzanilla, and all the different byproducts they create as time goes by and the veil becomes weaker.

We need to understand that a Fino and a Manzanilla follow the same process to be crafted, the difference in name is simply a geographical matter, as Manzanilla is the name given to biologically aged wines in Sanlúcar de Barrameda.

Each of these wines starts as a regular white wine that, once fermentation is finished, is fortified up to 15% ABV because this is a graduation in which these 4 yeasts can survive but bacteria don't feel comfortable, thus becoming a traditional way of preserving the wines preventing them from turning sour. For its survival, the veil not only needs mild temperatures and high humidity as I've previously mentioned, but it also needs a constant supply of nutrients and oxygen.

This fact helps us to understand why the dynamic aging method of the solera and criaderas (learn all about it) is used to age wines instead of bottling single vintages. The fact that the Fino and Manzanilla barrels don't get filled right at the top leaves an empty head for the oxygen to fill in and for the veil to develop and feed on it. These wines are a blend of several vintages where each barrel is refreshed with younger wines that bring in the necessary micro-nutrients to support the survival of the veil of flor.

Sobretablas = adding the young wine from that particular vintage | Rocío = refreshment | Saca = % of wine which is bottled

We wanted to put this block together because the development of the veil of flor is not linear but it does reach a peak at a certain stage of its life. During the first 2/3 years of aging, the veil of flor has not yet dominated the character of the wine (Here is where we fit our first wine, the Fino Ceballos) preserving a lot of the primary aromas. Then, we have the wines in that range that go from 4 to 5 years, where a good 80 to 90 percent of the aromas in the wine are dominated by biological aging (here we presented the Manzanilla Origen). Finally, when the activity of the veil of flor decreases due to the lack of nutrients, is when we gain a deep range of more complex aromas because there'll be some oxygen starting to get in touch with the wine and, also, the veil when it dies it falls into the bottom of the barrels starting to behave like lees (we finish the block pouring Manzanilla Pasada Blanquito).

As a curiosity, it's important to mention that controlling the development of the veil of flor has also become a tool that many winemakers can use in their favor. When a winemaker faces a warmer vintage or produces wines coming from poorer soils they can empty the "bota" (sherry butt) to expose the veil to a larger surface so it can consume alcohol and glycerine more intensely producing higher doses of acetaldehyde improving the sharpness and verticality of the wine. However, in cold vintages or those vineyards located by the coast, it doesn't make that much sense to have a large surface of flor in contact with the wine because the wine is already fine enough, so we can fill up the "botas" a bit more so we reduce the effect which the biological aging will have in the final wine.

3. Fino, Ceballos, Primitivo Collantes, NV

This Fino is produced from Collantes´ single vineyard called Pozo Galván in Chiclana (also a super Atlantic exposed area, which is why we could pour this Fino before Manzanilla, as it's even more ethereal than it). It is aged for 3 years in the solera system. The impact of the veil of flor is starting to be noticeable but the primary character of the base wine is still dominating: apples, mirabelles, chamomile, fresh almonds, and blossoming flowers. Its mouth is piercing, sharp, and dynamic. Almost like a sea breeze itself.

4. Manzanilla, Origen, Callejuela, NV

This Manzanilla comes from different Pagos (30% Macharnudo, 50% Añina, and 20% Callejuela approximately) grown in different subtypes of albariza soils. The harvest is delayed as long as possible, so they can reduce the amount of spirit added to the wine because of the natural development of higher ABV. The wine ages in butts with less headspace than usual, but the level inside the barrels is gradually lowered as the wine moves to subsequent criaderas, where it stayed for 5 years. This is an elegant Manzanilla, a bit more textural than you might expect but perfectly balanced by a vertical and saline backbone. The aromas imparted by the veil of flor are present, thus developing nuances like straw, celery, almonds, and sourdough on top of the fruit character (confit lemons, baked apples).

5. Manzanilla Pasada, Blanquito, Callejuela, NV

The grapes for this Manzanilla come from their vineyards in Pago El Hornillo. "Pasada" refers to the evolutive stage of this Manzanilla as it is 10-12 years old (average), old enough for the veil of flor to start weakening. It's incredibly elegant. Power and concentration with a refreshing piercing iodine character. Some evolutive notes such as roasting pumpkin seed, caramelized soy sauce, celeriac, and dried wildflowers show up seductively.

Last but not least, we couldn't forget about Amontillados in the third block. Etymologically speaking, Amontillado means "the wine that is gaining nuances similar to those in the wines from Montilla". We need to understand one thing here, and it's that the different styles of Sherry were born in a natural way in different sub-regions due to the conditions of their specific terroir. If we look at the area of Montilla where they have calcareous soils in which they grow varieties like PX that give full-bodied wines, then we understand that the veil of flor was a bit more stressed opening itself up to greater exposure to oxygen.

Thus, what we understand today as an Amontillado, it's a style of Sherry that has started aging biologically during the first stages of its life to then ending up aging oxidativey.

There are two ways for a winemaker to craft an Amontillado. The first one is as simple as refortifying the wine for a second time up to 17% ABV to stop the biological aging at the specific stage the winemaker wants. The second involves waiting patiently until the veil fades naturally as nutrients are consumed. In this case, not being refortified, we also gain ABV as the water evaporates and the alcohol concentrates. The latter, for me personally, is where magic happens.

6. Amontillado, Fossi, Primitivo Collantes, NV

The wine is aged for around 5 years under flor. After that time, alcohol is added, and the wine will spend another 8 years aging oxidatively. This is a super fresh glass of Amontillado, with a very thin yet vivace and sapid mouthfeel that doesn't lack complexity. Seaweed, chalk, bread crust, roasted nuts, grapefruit peel, aniseeds... Superb drinkability!

7. Amontillado, Origen, Callejuela, NV

This Amontillado has been 12 years under the veil of flor as it starts with the Manzanilla from the Blanquito solera (the previous manzanilla pasada we've talked about) and then 3 additional years under oxidative aging. Even if the veil of flor is almost gone completely at that stage, the wine was refortified a tiny bit. Amontillado Origen is dense, rich, and textural, but with a nice sharp and piquant vertical edge to it. Starts developing aromas such as hazelnuts, peanuts, mahogany, dates, and figs.

Even if it wasn't shown in the tasting, I want to talk to you about another Amontillado that we poured regularly in our pop-ups as it is the perfect example of that magical second way I was talking to you about:

8. Amontillado, La Casilla, Callejuela, NV

This wine spent an average of 25 years in the solera system. The first solera started with a 12 year old Manzanilla (Blanquito), and once the veil of flor disappeared naturally, then oxidative aging followed for 14 years. The first botas for this solera started in 1986 when the two brothers Pepe and Paco bought their first barrels. They used the Palomino grapes from vineyards in the Pagos Callejuela and Añina. Only 7 botas composed this solera, thus limiting the production to 500-ish bottles per year. This wine is solemn and unique. It is a direct witness to the passing of time. It is a little more vertical than the nose suggests, which is a great thing to happen, talking to us about its Oceanic provenance. Pickled walnuts, varnish, mahogany, douglas-fir, caramelized hazelnuts, tobacco leaves, iodine notes, dried apricots... Finesse at its best.

With this third block, the tasting concluded. As it's understandable, we didn't speak about Olorosos or sweet sherries because they didn't undertake biological aging. Why did we not include then a Palo Cortado? Simply because we don't consider that the influence of the veil of flor is enough to shape the character of modern Palo Cortados. We would need to look into VORS or pre-phylloxera references to understand what a Palo Cortado truly was. Nowadays, they are just Olorosos to us. But that's a topic for another post, because trust us, there's no mystery behind Palo Cortado.

Director at Fìon, Edinburgh


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