The Cocktail Wonk Guide to Sherry — Spain’s Magical Mystery Wine

The cool air is heavy with the smell of wine as our guide beckons us toward a wooden cask perched at eye level on a stand. We’re in an immense, high ceilinged stone warehouse in the southwest of Spain, beams of sunlight streaming in from windows high above us. Reaching behind the cask, he flips a switch and we realize the circular top and bottom barrel ends are made of clear plastic. The cask is mostly full of pale liquid, but floating on top is a quarter-inch thick layer of what appears to be mold.

Wait? Is this normal? Is it safe to drink? Odd as it may seem, the thick layer of yeast cells protect the wine from oxygen and creates an aging environment practically unique within the wine and spirits world. But this unusual yeast layer, known as “flor,” is just one of many dimensions that gives sherry it’s most unusual flavor–and makes it much more than just another wine.

Manzanilla, Oloroso, solera, criadera, En Rama, VSOR…so many terms and concepts come at you fast and furious when you first start wrapping your head around sherry. While I enjoy wine, I’m a spirits and cocktails guy at heart. But the breadth of sherry styles, the stories behind how they’re made, and sherry’s finesse as a cocktail ingredient captures my imagination far more than any other wine.

If your notion of sherry is that it’s all sweet, raisin-forward wine similar to port, you’re very much mistaken. The reality is that most sherry is on the very dry end of the spectrum, with intense, savory flavors great for enjoying on their own or as a base for cocktails like the Pizzicato Passage, Flor de Jerez or the classic Sherry Cobbler. Of course, there are sweet sherries as well, lending themselves to other creative uses in cocktails. But to dismiss sherry because you believe it’s simply sweet dessert wine is a huge mistake.

My interest in sherry goes back a few years, and I’ve written about sherry in the context of rum cocktails. However, it wasn’t until a Tales of the Cocktail 2016 session hosted by Gonzalez Byass that I became obsessed with travelling to the Jerez region of Spain to immerse myself in its production. In early 2017, Mrs. Wonk and I scratched that itch, spending two epic weeks travelling across Spain, setting aside five days to spend in Jerez de la Frontera, visiting Gonzalez Byasss, Lustau, and Williams & Humbert.

This post sets up the baseline knowledge for subsequent posts about those visits.

Sherry – A Basic Definition

Like many other wines and spirits, sherry is defined by a unique “geographical indicator” or “GI,” which sets out the allowed raw materials and production processes that must be followed to legally label the end results as sherry, or in its native Spanish, Jerez. In Spain, a geographical indicator is known as the Denominación de Origen (or DO); sherry’s DO is regulated by an industry oversight group known as the Consejo Regulador, which sets the rules and monitors compliance.

A very simplified synopsis of key sherry regulations is as follows:

The grapes must be grown in a particular region in southwestern Spain, known informally as the “sherry triangle.” The triangle is formed by three towns in the Cadiz province: Jerez de la Frontera, Sanlúcar de Barrameda, and El Puerto de Santa María. Jerez de la Frontera is the largest of the three and the focal point of most sherry production. It’s a few kilometers inland from the coast, whereas the other two cities actually perch along Spain’s Atlantic coast.

Grapes must be white, and of one three varietals: Palomino, Pedro Ximinez, or Moscatel. The majority of sherry, i.e. the dry styles (see below), are made with Palomino grapes. Pedro Ximinez and Moscatel grapes are only used for the sweet sherry styles. The vineyards where the grapes grow have a very light colored, chalky soil known as albariza, particularly good for growing Palomino.

To extract the juice, sherry winemakers use multiple pressings. The first pressing has relatively little tannins and solids in it, creating a light, delicate base wine. The second pressing results in a more robust, tannic base wine. Different styles of sherry use either the first or second pressing to help create the target flavors.

After the grapes are fermented to create a base, the unaged wine, is fortified with destillado, a mixture of distilled grape spirit and already matured sherry. Adding the destillado to the unaged wine increases its natural alcohol content by just a few percentage points. The amount of fortification and when it’s added are important tools the sherry maker uses to control the end result. For example, a Fino or Amontillado sherry can be made from the same base wine—it’s a matter of fortification levels and when it’s done. As well, multiple fortifications of a wine may happen over time.

The fortified wine must be aged for at least three years. Unlike vintage wines, which spend their entire aging time in a single cask, the vast majority of sherry ages in multiple casks, periodically moving from one cask to another and blending with sherry from other casks. The generally known term for this semi-continuous blending is “solera” aging, which I’ll cover in detail later. However, it’s important to understand that vintage sherry (non-solera aged) exists.

In the modern era, sherry is aged in oak casks. The typical size of a sherry cask is 600 liters, which is 600 liters, or about 3 times the size of the typical bourbon cask. Given how much sherry is produced, it’s no surprise that there are number of cooperages in the area. In addition to the sherry houses, the cooperages also supply casks that eventually end up on distant shores. More on this later.

All in all, the above doesn’t sound particularly complicated. However, there’s much more to sherry production beyond these basics, so let’s move to the deep end of the pool.

Biological vs. Oxidative Aging – Fungus Is Your Friend

When you think about cask aging a wine, you probably imagine the liquid filling the entire cask. However, in reality there’s always some amount of air, and over time, the liquid very slowly evaporates through the porous wooden walls in a process known as the angel’s share. Air seeping (slowly) through the barrel walls replaces the liquid. Given enough time, the entire cask will fill with air. This is an important point because the liquid in a cask undergoes constant exposure to oxygen. Liquid, air, and wood collaborate to change the liquid, in a process known as oxidative aging.

With some styles of sherry, however, there’s a critical fourth player added to the mix: A living yeast fungus known as flor del vino, aka flor or flower, that forms a flexible crust covering the entire surface of the wine in the cask. In this case, flor dramatically reduces the wine’s exposure to the air above it within the cask. As a living creature, the flor needs nutrients; what it consumes is various components of the wine beneath it, including residual sugars, glycerin (a natural component of wine), and ethanol. This process, called biological aging, results in a very dry style of wine, as the two principle ingredients we perceive as sweet (sugars and glycerin) are consumed by the flor.

Not all sherry styles are biologically aged. But for those that are, maintaining a healthy flor is critical. The thickness and consistency of a cask’s flor changes seasonally over time, and casks are checked on a consistent basis. A flor’s health is directly tied to the wine’s alcohol content: Too high an ABV and the flor withers and dies. When making a sherry style that’s not biologically aged, the winemaker fortifies the wine to a high enough level (around 17 percent ABV) such that flor can’t survive.

In addition to elevated ABV, rough handling can also damage a cask’s flor. During normal operation, a cask is never fully emptied and the flor lives indefinitely, with new nutrients brought in by the addition of younger wine (described further below). Since some amount of wine is frequently added and removed from casks containing flor, special tools are used to sample, add, and remove the wine while minimally stressing the flor. The most classic of these is called the venencia, essentially a small cylinder on a flexible stick—either carved from a single piece of cane (the old way) or a combination of PVC and stainless steel (the new way).

Some styles of sherry are aged both biologically and oxidatively. To make these, the winemaker first fortifies the wine to a level where flor can live (around 15 percent ABV) and lets the wine age for the desired duration. To switch over to oxidative aging, the winemaker adds additional fortification to bring the wine up to a higher ABV. This kills off the flor, which settles to the bottom of the cask.

Sherry Styles

Up to this point I’ve avoided introducing the different sherry styles like Fino or Palo Cortado in order to focus on the “knobs” that can be adjusted to create a particular style. With these defined, let’s take a look at the D.O.’s officially defined styles:

Fino: A very dry, pale sherry made from Palomino grapes. Its aging is entirely under flor, so it’s 100 percent biologically aged. In Spain, Fino is the most commonly consumed sherry varietal. In the Jerez region, it seems to be the default “white wine” of choice—served crisply chilled, if not downright cold. Since Fino is entirely biologically aged, it changes the fastest once you open a bottle, exposing the contents to air. Treat Fino like any other wine in that regard, best served within a few days of opening.

Manzanilla: Also a very dry, pale sherry made from Palomino grapes and biologically aged. The critical differentiator between Fino and Manzanilla is that Manzanilla must be made in the town of Sanlúcar de Barrameda, on the Atlantic coast. Some say that the proximity to the salty ocean air gives Manzanilla a lighter, more briny flavor. Technically, Manzanilla has its own distinct Denominación de Origen, but for our purposes it can be considered a sub-variety of Fino.

Amontillado: A moderately dry, medium colored sherry made from Palomino grapes. Amontillado first ages biologically like a Fino. However, at some point the flor dies off, either accidentally or intentionally via fortification, and the rest of the aging is oxidative. It’s during this oxidative aging that most of the color is imparted. Amontillado, with its robust, savory, nutty notes, is often a favorite of cocktail mixologists.

Palo Cortado: A moderately dry, medium colored sherry made from Palomino grapes. Like Amontillado, Palo Cortado first ages biologically and then oxidatively after the flor dies off. While Amontillado and Palo Cortado have similar production methods, Palo Cortado tends to spend less of it aging time under flor. Some people say Palo Cortado bridges the gap between the Amontillado and Oloroso styles.

Oloroso: Less dry than the preceding styles, yet not yet sweet, Oloroso is typically made from the second pressing of Palomino grapes. Its aging is entirely oxidative, as the initial fortification gives an ABV too high for flor to form. Being oxidatively aged its entire life, Oloroso’s color can be quite dark. Casks seasoned with Oloroso are in very high demand for aging other spirits, especially Scotch whisky. The unique sherry notes found in many single malts (such as Macallan) are directly attributable to using Oloroso-seasoned casks. Because Oloroso is oxidatively aged, with proper care it can retain its original flavor longer for several months after opening.

Pedro Ximénez: An extremely sweet, dark sherry made from Pedro Ximénez grapes. This type of sherry is oxidatively aged, and alternatively referred to as “PX.” After harvesting the overripe grapes, they’re left to dry in the sun, effectively creating raisins. As you’d expect, the raisin flavor carries through into the final sherry. Pedro Ximénez has a sugar content that’s typically around 400 grams per liter of wine. (Yes, that’s an insane, diabetes-inducing amount of sugar.) The high sugar content of the pressed juice makes fermentation difficult, so the majority of its alcohol content comes from the fortification process. Because there are not many Pedro Ximénez vineyards left in the sherry triangle, the sherry DO allows the grapes to be grown in the nearby Montilla-Moriles region.

Moscatel: An extremely sweet, dark sherry made from Moscatel grapes. Like Pedro Ximénez, the grapes are picked extremely ripe and dried in the sun. For our purposes, Pedro Ximénez and Moscatel sherry use a similar production process, and the only critical difference is the grape varietal.

Solera Aging Basics

When a wine or spirit spends its entire life in one cask, it develops a flavor profile unique to that particular combination of liquid, cask, and environmental conditions, such as seasonal temperature swings. Sometimes the results in a cask are amazing, sometimes not. A master blender’s task is to sort through all the different cask contents and construct a blend true to the house style. And that can be challenging to pull off, year after year.

Solera aging turns the whole concept of blending after aging on its head. Instead of thinking about individual casks, with solera aging you work with many casks working as a single system. At periodic intervals, a fractional part of the liquid is removed from one set of casks, blended together, and placed into another set of casks.

Let’s look at a very simple example of how solera aging works. Imagine you’ve got three casks full of wine labeled X, Y, and Z. Cask X is full of wine aged for three years, Y has wine aged for two years, and Z has wine aged for one year.

Your wine is in demand, so you decide to bottle one-third of a cask of your best wine, i.e. the three-year aged wine from Cask X. After withdrawing one third of the contents, you top it up with wine from Cask Y. Now Y is one-third empty, so you fill it back up with one-third of the contents from Cask Z. Being a good winemaker, you fill up Cask Z with fresh-make wine.

When all is said and done, you’ve extracted and replaced one-third of a cask from the system as a whole. The average age of the wine in Cask X has dropped, but so has the average age in Y and Z. A year later, you repeat the process: Remove some fraction of wine from X, top up each cask with wine from the next “younger” cask, and put fresh wine into the youngest cask. This can be repeated ad infinitum, always taking out fractional amounts from the oldest cask and replacing with an equivalent amount added to the youngest cask.

In this setup, a given wine molecule may race through all three casks in as little as three years, or it may languish in cask X, Y, or Z for years before it moves to the next cask in the system. Every cask is a blend of wines of different ages, but the average age of X is always older than Y, and Y’s average age is always older than Z.

Let’s make our example a bit more complicated now. Imagine you have five X casks (X1, X2, X3…), five Y casks (Y1, Y2…), and five Z casks (Z1, Z2…). When it comes time to bottle some wine, you extract equal amounts from all the X casks, blend, and bottle it. You then remove an equal amount from all the Y casks, blend it together, and refill the X casks with the blend. Finally, you perform the same extract, blend, and refill steps to top up the Y casks from the Z casks.

The above example is a three-level solera with fifteen casks. By sherry production standards, this is a tiny system. Soleras at big sherry houses may have ten or more levels, and hundreds of casks for a given level.  In simple solera system, the different cask levels are stacked on top of each other, pyramid style, with the oldest casks on the bottom, and the youngest casks on top. It’s easy to picture a simple siphon refilling a cask from the cask above it. While a useful mental image, it’s not how it’s actually done, as everything removed from a given level must first be blended before refilling the level below it.

At this point let’s discard the above simple model and talk about solera management as it’s practiced. Solera actually means “soil” or “floor” and technically refers to just the oldest casks, usually at ground level. The younger levels that feed into the solera are known as criaderas, meaning cradle. The criaderas levels are numbered, and somewhat confusingly, the criadera with the oldest wine has the lowest number, i.e. the first criadera. An example with four levels makes this simpler:  Wine is removed from the solera level, which is refilled from the first criadera. The first criadera is refilled from the second criadera, and the second criadera refilled from the third criadera. New wine is added to the third criadera.

Solera Management – Running the Scales

The process of extracting wine from the solera level and refilling each level from a criadera is known as “running the scales.” With some solera systems reaching into the thousands of casks, it’s obviously a task that requires a significant amount of time and coordination. Literally every cask must be accessed to extract and refill some portion of its contents. Along the way, each cask’s contents must be checked to ensure the wine hasn’t gone bad, or some mishap like the flor unexpectedly dying hasn’t occurred. With the sheer volume of wine involved, running the scales with a solera system bigger than a few casks is something best done via pumps, machinery, and a whole lot of coordination.

Once solera systems are up and running, they’re almost never moved or disturbed, especially if it’s flor-based solera with something like Fino. Some have been in place for close to a hundred years.  If a particular cask goes bad or needs repair, it’s a delicate operation to fix or remove it while leaving all the surrounding casks in place.

Each individual solera system has its own operating parameters, including how frequently the winemaker runs the scales and how much they take out at any given time. For younger, inexpensive Finos, sherry makers may run the scales four times per year. For very long aged, high-value soleras scales are run far less frequently. Each solera system is individually tuned for optimal results and predictability.

One downside to a solera system is that if there’s a sudden surge in demand for a product, you can’t just withdraw vastly more sherry than you normally would and expect subsequent batches to come out substantially similar to prior batches. However, if demand drops and you bottle less, you can simply run the scales less frequently, and the average age at each level increases. When demands picks up again, you’ve got an even longer-aged sherry to bottle.

While the solera and criadera levels in a given system may number ten or more, you can’t just stack the barrels on top of each other, pyramid style, up to the ceiling. Stacking barrels more than four high is risky, as the weight can crush the lower barrels. Thus, a solera system with more than four levels is split into chunks, each no more than four barrels high. The solera and first three criaderas are in one part of the aging facility, and nearby another stack contains criaderas four, five, six, and seven, for example.

With thousands of casks composing dozens of solera systems in a single building, labeling and keeping track of casks can be a logistical headache. A standardized notation for casks using numbers and arrows has evolved to assist with this.  For instance, at the end of a row of casks, you might find a cask labeled “1/25” along with an arrow pointing to the left. This means that the cask is the first of 25 similar casks, and that all the casks to the immediate left are of the same level. Large solera systems may also have arrows angling diagonally up or down, indicating that the cask at different physical levels (above or below the marked cask) are in the same criadera level.

Another number you’ll frequently see on sherry casks is the desired fill level of the cask, expressed in units of arroba. An arroba is equal to 16.6 liters, or 4.38 U.S. gallons—the size of a traditional pitcher used to carry sherry from one criadera to another. A typical cask fill level we saw was around thirty arrobas, or 500 liters. Sometimes you’ll see a series of similar arroba values stacked vertically, indicating the desired fill levels of casks at different criadera levels.  Complicated? Yes. But this system evolved well before computers, barcodes, and handheld scanners. Some traditions die hard.

Solera aging techniques aren’t confined to just sherry production. The concepts have spread to the spirit world. Brandy de Jerez, a grape brandy aged in the sherry triangle also uses solera aging. Likewise, solera aging is popular with some rum producers, especially those in the Caribbean with a Spanish heritage.

Sherry Bodegas – Cathedrals of Wine

A critical aspect of successful sherry aging is a cool, moist environment with minimal changes in air temperature. Located in the hot, dry southwest of Spain and heated by the fierce Levante winds, the sherry triangle is anything but cool and moist year round. Since modern air conditioning and climate controls didn’t exist when sherry production began in the early 1800s, a low-tech way of creating optimal conditions evolved. The aging warehouses, known as bodegas (aka “cellar” in English) have an architectural style that allows conditions typically found in underground cellars to be replicated above ground.

Bodegas have high ceilings and thick, whitewashed walls. The ceilings, forty feet or more, allow the heat to rise well above the casks and escape through small windows near the top of the structure. The high arches found in many older bodegas give the impression of a Moorish mosque, entirely fitting giving this region of Spain’s historic background. More modern bodegas have geometric shaped ceilings that allow rainwater to be easily collected and reused. Whitewashing the bodega walls minimizes the heat transferred to the structure via harsh sunlight.

The floor of the bodega is usually covered in albero, a rough, sandy, clay-type dirt. When the humidity drops below the desired level of around seventy percent, sprinklers come on to wet the soil, driving up humidity and cooling the air.  Windows are covered with panels of traditional woven grass mats called espadrille—yes, the same as those summer vacation sandals in your closet—to allow air to circulate but to keep sunlight out.

Biologically aged sherry casks (that is, those with flor) are kept in bodegas (or parts of a bodega) that are the coolest, which is typically those with the highest ceilings. These wines are also kept lowest to ground level, where it’s coolest. Sherry undergoing oxidative aging is less sensitive to heat, so can age in warmer bodegas or be stacked on higher levels.

In touring a number of bodegas in Jerez, we saw buildings of all shapes and sizes. The smallest were the size of a large house in terms of square footage, holding a few hundred barrels. The largest, at Williams & Humbert in Jerez de la Frontera, is beyond comprehension, holding over 60,000 barrels of sherry, brandy, and rum under one continuous roof.

All in all, the sherry bodegas of Spain are a photographer’s dream setting. Everywhere you look is something picturesque, like the tiny ladder and a small glass of sherry left on the albero floor for the local mice. The rows and rows of black painted barrels never seem to get old. Dramatic lighting from windows high above, woven window coverings with sunlight poking through, dirt floors, cryptically chalk-labeled casks. Does it get any better than this?

En Rama

Prior to bottling, most wines undergo a hefty amount of filtration and clarification. While this makes for a consistent, shelf-stable product, it also removes a nontrivial amount of flavor. In the last two decades, some sherry houses have begun releasing small batches of sherry, En Rama style.  Literally “from the vine” or “raw.” These sherries undergo substantially less processing prior to bottling, so taste closer to what they would straight from the cask.

The downside to En Rama sherry is its shorter shelf life compared to its traditionally bottled equivalent. They’re also more sensitive to how the bottle is stored, e.g. excess heat in a storage room.  Thus, there’s a bit of “buyer beware” when buying an En Rama. On the back of most sherry bottles is a code from which you can figure out when it was bottled. However, the format of the date codes is anything but standardized across producers.

Cream Sherry

Although not an official style of sherry per the current sherry D.O., a number of sherries produced are are a blend of mostly Oloroso and a much smaller amount of Pedro Ximénez. This unofficial style is known as cream sherry–Harvey’s Bristol Cream being the best known example. It should be obvious by now that this product isn’t made in Bristol, England, nor does it contain any dairy cream. Chalk it up to long-dead British history, of which there’s a ton of in the sherry triangle. You may also see cream sherry referred to as “sweet oloroso,” on in sherry producer Lustau’s case, “East India Solera.”

Ultra-Long Aged Sherries

In the distilled spirits world, a product like single malt Scotch whisky aged for twenty years might command hundreds of dollars, and a thirty-year aged version could be well into the thousands of dollars. However, in the sherry world, an equivalently aged sherry sells for less than $100 a bottle. Those massive solera systems, in place for decades, hold a huge amount of value.

As a consumer, one question before you shell out big dollars for a supposedly long-aged sherry is, “How do I know if it’s as old as the label claims?” While any producer can put fancy words like Extra Old or Grande Reserva on a label, these terms have no legal definition. Sensing the opportunity for shenanigans, the Consejo Regulador stepped in to create two officially recognized and verifiable age claims for sherry.

The term VOS, an abbreviation for the Latin Vinum Optimum Signatum, indicates a sherry with an average age of twenty years or older. While some of the bottles’ contents may be only fifteen years aged, other parts could be aged for twenty-five years or longer. However, the average age of all the contents is at least twenty years. Even more premium than VOS is VORS (Vinum Optimum Rare Signatum). An easy, if anglicized way to remember what VORS means is “Very Old Rare Sherry.” VORS sherry has a minimum average age of thirty years, which is kind of crazy when you think about the wine sitting in a barrel and evaporating over that many decades.

You’re probably wondering how the average age of a sherry can be verified. Science to the rescue! Producers who use these designations must submit samples to the Consejo Regulador for carbon dating. In addition, there are requirements on the solera’s capacity relative to what’s extracted for bottling, as well as taste evaluation by a panel of outside experts.

Wrap Up

At this point, your head may be swimming with sherry styles and terminology. I promise that with a little dedication, it all starts to make sense. If you’re new to sherry, the key thing to remember is that it’s first and foremost a wine and not a distilled spirit. As such, you don’t want to consume it at room temperature. Chilled is best! Once opened, keep the bottle in the refrigerator and ideally vacuum-sealed, rather than leaving it at room temperature on a shelf. The lighter, biologically aged styles are at optimal flavor for a week or less when stored properly after opening. The oxidatively aged Sherries last a bit longer, but not indefinitely.

A very helpful thing we did before touring the sherry triangle was to visit our local store that stocked a number of sherries, purchasing a small bottle of each style – Fino, Manzanilla, Amontillado, Palo Cortado, Oloroso, and Pedro Ximinez—for at-home studying. Luckily, many sherries are available in half-sized (375ml) bottles, saving you a bit of money. At home, we properly chilled them all, set out a glass for each bottle, and worked our way through them, going back and forth between them repeatedly to reinforce what stood out about each particular style.

Having spent nearly a week in and around the sherry triangle, we came to understand that sherry isn’t some “special occasion” beverage. Rather, it’s “just wine,” albeit a lot more interesting than your basic red or white table wine and at nearly equivalent prices. Every part of a meal has a sherry that complements it well. Fish, fowl, fauna, steak and dessert – there’s a sherry that works for each!

Beyond drinking sherry as a wine, there’s the whole realm of cocktails where sherry style brings something unique to the equation. Fino and Manzanilla are great for drying out a cocktail, providing a tangy counterbalance to something sweet. An Amontillado or Oloroso brings serious structure and savory, nutty notes to a drink without bumping up the ABV. And a PX can take the place of a flavored syrup and provide serious dried fruit notes.

In follow-on posts to this one, I’ll write in detail about our visits to each sherry bodega, with lots of photos. However, this post provides my spin on the basics of sherry, and hopefully entices you to open your mind to the incredible diversity and great value it offers.