Category Archives: Wine Education

Spanish Fiesta y Cata de Vinos

Blind Tasting of Spanish Wines — Before and After

Wine class with Sommelier Mary Horn is always an adventure, serious in purpose and big fun in the moment. Five of us who are WSET Advanced or Diploma (but who do not work full-time in the industry) gather regularly for a rigorous blind tasting tutorial with Mary. That usually involves at least eight different wines, plus a “mystery wine” to start the class with Mary calibrating the assessment process. We then hunker down quietly for about 30 minutes, moaning occasionally because it is so difficult to discern the provenance and character of each wine in only four minutes!!

54 Glasses of Wine!!

Our January class featured Spanish wines. A selection of Spanish cheeses — Manchego, Mahon, Drunken Goat — fueled discussion of the wines. How did we do? Not so great. This was a particularly challenging class, with only the most powerful Garnachas and classic Tempranillos winning correct assessments.

The line-up of wines, before and after, are featured at the top of this post. As a belated “cheers” to the new year, we enjoyed a Spanish meal of Paella, Fiesta Salad (recipe from Deborah Birckhead), and Crema de Esponja (aka Flan de Valencia). Recipes (adapted to my personal taste) follow. Enjoy!!

Paella (6-10 servings depending on portion size)
Traditional Paella has either seafood or meat, but not both. I really like the combination, so I have adapted a recipe from Rachel Ray she calls “Perfect Paella.” If you don’t already have a Paella pan, there are many options available online. (Note: I am allergic to mussels, so I don’t use them in my Paella. But if you love them, Rachel Ray’s recipe calls for 18 green lipped mussels, cleaned.)

2 T extra-virgin olive oil
3 cloves garlic, crushed
1/2 teaspoon crushed red pepper flakes (add more or less depending on how hot you like your food)
2 cups enriched white rice (the classic rice is bomba, but if you can’t find that type, use either small- or medium-grain rice; do not use long-grain rice)
1/4 t. saffron threads (I typically use a wee bit more)
1 bay leaf
4-6 sprigs of fresh thyme
1 quart broth or stock (I use either all chicken stock or a combination of chicken and fresh fish stock from my local fishmonger)
1 14-ounce can of chopped tomatoes with green chiles
1 red bell pepper, seeded and chopped
1 medium onion, chopped (optional)
1 cup (or more) frozen peas
2 lemons, zested
Seafood options: 1 pound of medium shrimp and/or lobster chunks, plus one can of baby clams, drained
Meat options: 2+ pounds of any combination of white/dark meat chicken (cubed) and any type of mild to spicy sausage (sliced). I have also added roast pork or lardons to pop up the flavor.

It is much easier to make this dish doing advance prep, especially with guests present!  I always cook the meat ingredients ahead of time, refrigerate, and then bring to room temperature before starting to assemble the Paella. Use only olive oil, salt and pepper — no additional spices. I make sure the seafood is cleaned, shelled, chopped (for lobster), etc., and ready to be added to the Paella at the end for just a few minutes of cook time.

Preheat the Paella pan, then add 2 T. olive oil, crushed garlic, and red pepper flakes. Sautée rice 2-3 minutes. Add saffron threads, bay leaf, thyme sprigs, and broth. Bring liquid to a boil over high heat, then reduce to a simmer.

After about 10 minutes, stirring occasionally, add the can of tomatoes, optional can of baby clams, peas, and lemon zest. Stir. In 2-3 minutes, add the meat which will absorb some of the juice. When the juice is nearly absorbed, add the seafood for about 3 minutes until it is fully cooked. (Don’t be afraid to add a little more broth toward the end with the seafood if you think the dish is getting too dry.)

Remove the bay leaf and thyme sprigs. Serve with lemon wedges and warm, crusty bread.

Fiesta Salad with Lime Cilantro Vinaigrette (6-8 servings)

1/4 to 1/2 cup chopped shallots
1/4 cup fresh lime juice
1/4 cup chopped fresh cilantro
1 T. minced garlic
1/2 cup vegetable oil

Combine first 4 ingredients in a medium bowl. Gradually whisk in oil. Season with salt and pepper.

3 cups thinly sliced red leaf lettuce
3 cups thinly sliced Napa cabbage
2 plum tomatoes, chopped
1/2 red bell pepper, thinly sliced
1/2 yellow bell pepper, thinly sliced
one avocado, diced
1/3 cup cooked corn
1/4 cup pepitas or pine nuts
1/4 cup thinly sliced onion (optional)
1/2 cup crumbled queso anejo or feta cheese (about 2 ounces)

Combine all ingredients except cheese. Toss with vinaigrette to coat. Top with cheese.

Crema de Esponja (or Flan de Valencia)
Enjoy these recipes!

Barbaresco vs. Barolo: What’s the Difference?

In my most recent article written for French Wine Explorers, I explore the subtle but important differences between Barbaresco and Barolo winegrowing regions and the resulting styles of wine. Spoiler alert: it’s mostly the Mother Nature factors, but there are a few winemaker choices and aging rules that also explain style differences. Enjoy the story, but more importantly, love the wine! Even better, join French Wine Explorers for the 2018 “Treasures of Tuscany and Piedmont” tour! Kathy Merchant

Italian Wine Labels

What’s actually in the bottle? Does the wine label tell you the place, the grape, or both? I hope you will enjoy my recent article, written for American wine travel company French Wine Explorers, to demystify the various ways Italian wine labels explain the product within.

Introducing “Ask Kathy”


The world of wine can be intimidating. Where should I shop? Which wine goes best with a certain meal or cuisine, or favorite cheese? What is Carménère? Where is Irouleguy? What’s the best itinerary to enjoy the wines of Tuscany? Why is Pinot Noir so difficult to grow? Where can I take wine classes, and which type of education is best for me? Is Soave and place or a grape? Can you help me “translate” a German wine label? And so it goes…

This is an experiment to gauge interest among readers in addition to my immediate friendship network (and to try using WordPress as the vehicle)! If you have a question, just fill out the “leave a reply” comment box on the “Ask Kathy” page of my website (or use this post), and I will get back to you as quickly as I can.

Photo credit:

Southwest France: Diverse by Design?

Southwest France (Sud Oest) is best known for what it isn’t. Frankly, and unfortunately, it’s not widely recognized at all. With an accompanying eye-roll, I must report that many people have asked me – quite genuinely – “where is Southwest France?”!

Let’s get positioned on the map. Sud Oest is the deepest rural France, la France profonde. “In terroir terms, it’s a big area and rather difficult to generalise about, but most of the high-quality vineyard zones…owe their existence to the slopes created by rivers coming down either from the Massif Central, or from the Pyrenees. The overall zone is the Aquitaine Basin, and almost all of the soils…have been developed from sedimentary rocks of various kinds, or by the action of the rivers themselves.”[1]

  • To the west, the Atlantic Ocean curves along the French coastline, moderating altitude and winter weather (along with several smallish rivers) to create both maritime and semi-continental climates with plenty of rainfall.
  • To the south, the Pyrenees Mountains separate France from Spain. Beautifully majestic and occasionally craggy, the mountains are quite permeable. Basque language, food, and culture seep into the foothills on the French side.
  • To the north, Southwest France stretches inland, cupping the edges of Bordeaux and capturing misty river effects to generate some of the world’s greatest (if little known) sweet wines.
  • To the east? Well, that’s a good question. Several of the appellations that comprise Southwest France are actually nestled within the great Massif Central. The city of Toulouse might be a good eastern marker signaling the regional shift to Languedoc-Roussillon.
Map Credit: Wine Folly

Map Credit: Wine Folly

So what is (or is not) Southwest France? It is not an official appellation; it is a collection of appellations, glued together for convenience into a sort of cornucopia. Its terroir is not homogenous, although there are some common threads. It is the spiritual home – exclusive, in some cases – to spectacularly interesting grapes. Despite New World claims to the contrary, Malbec and Tannat can rightly claim Cahors and Madiran, respectively, as their spiritual homes. It’s not all obscure and mysterious, though. The appellations closest to Bordeaux do grow international varieties and make familiar blends.

This all adds up to a perplexing global-market branding nightmare for the winegrowers of Southwest France. There is very little that ties this huge geographic region together naturally as either an appellation or a brand. What might it be called instead? South X Southwest? Pyrenees North? Bordeaux Near? Gascony? High Country? l’Aquitaine?

Contributing to the overall brand issue is the fact that only about 25% of the 330 million bottles produced in Southwest France is AOC wine. Most of it – nearly 2/3 – is a regional designation of IGP (formerly Vin de Pays), and the rest is basically table wine for local markets. It is difficult to lift up and distinguish the highest quality wines.

It’s quite possibly impossible to create a proper synthesis of the region. While this alignment and branding problem is being sorted out, perhaps at a smaller scale on an appellation by appellation basis, the interim solution seems clear to me. Take a deep breath, hire a driver, plan a wine route that matches your sense of adventure, and enjoy by design the diversity of Southwest France. Just be sure to plan enough time to make the most of the >1,800 km touring experience!

Up next: Part 2 | History, Food & Wine

[1] Thank you to Andrew Jefford for the use of his extensive reference notes and excellent leadership of a Wine Scholar Guild tour of Southwest France.

Tradition Meets Innovation in Bergerac, FR

(This article was published October 20 by Wine Scholar Guild)

Day one of the Wine Scholar Guild (WSG) study tour of Southwest France, led by Andrew Jefford, was a very special opportunity to spend quality time with the owners/winemakers of three appellations, each providing a different glimpse of the diverse terroir of the region.

A bit behind schedule, we stopped for lunch at La Flambée near Bergerac just before 1:00. Bruno Bilancini had earlier explained the region’s daily rhythm of cool mists lasting until about 1:00, then giving way to warm sunshine (and thus perfect conditions for botrytis). The daily weather story was right on schedule!
Back on the bus, warmed by a lovely meal and and a preview of a white wine from Château Tour de Gendres, we headed to our third and final visit of the day in Bergerac with winemaker Luc di Conti. Instead of vineyard cats, we were greeted enthusiastically by a boisterous pooch who was determined to latch onto the knitted scarf of one member of our group.

In Ch. Tour’s vineyards we walked high atop a hill where we could see clearly the patchwork quilt of soils that provide great diversity and a perfect setting for organic farming (since 1996) of each parcel in a different manner. While the complete picture of the di Conti family vineyard holdings encompasses 50 ha, Luc farms 20 of them, choosing the 6 ha closest to the winery and cellars for biodynamic farming. When asked whether organic farming is more expensive than traditional commercial methods, Luc said unequivocally “no. If you are playing chess, you are always one step ahead. The same is true of viticulture.” After 20 years, nature is in balance at Ch. Tour and inspires new directions such as the dozen amphorae where Luc is also making orange wines.

Our tasting included a sample of Sauvignon Blanc from amphora (no skins, 10 days in the vessel) to compare with SB from a wooden vat. The amphora sample was cool, cloudy, slightly effervescent and sweet. The vat sample was warmer and also cloudy at this stage; though there was no sign of effervescence, there was more residual sugar. Continuing with comparisons, we tasted a vat sample of 2016 Bergerac Blanc (Muscadelle a Petits Grains) and a finished sample from 2014 which had been aged 80% in vat and 20% in amphora. The vat sample was quite leesy and tasted of pamplousse (grapefruit), while the finished wine was rich and full bodied with a slightly saline character. The vines for a 2014 Sauvignon Blanc are 80 years old, grown on calcere soil, resulting in a style typical of SW France. The final taste was a sample of 2015 Cabernet Franc, aged 14 months in a vat, ready to spend a year in bottle prior to release.

Chateau Tour Des Gendres

Chateau Tour Des Gendres

Southwest France: Monbazillac, Pecharment and Bergerac

Day one of the Wine Scholar Guild (WSG) study tour of Southwest France, led by Andrew Jefford, was a very special opportunity to spend quality time with the owners/winemakers of three appellations, each providing a different glimpse of the diverse terroir of the region.

Chateau Tirecul La Gravière

The misty morning launched with great aplomb: sweet breakfast treasures from Monbazillac. Standing with us on the edge of vineyards where botrytised grapes awaited the launch of harvest (by hand) on October 19, Bruno Bilancini led a discussion of the vineyard’s primarily clay (with a bit of limestone) terroir, explaining the influence of being situated in the microclimate of a valley on the left bank of the Dordogne River and the effects of slopes that face north and east (rather than the more customary south and west). Although Sauternes is perhaps better known than Monbazillac, the latter has twice the vineyard area. We also savored a vineyard sampling of raisined Semillon and Muscadelle grapes. The Bilancini family’s hunt for their white vineyard cat — yes, cat! — added a suspenseful moment to the visit.

Winemaker Bruno Bilancini; Wine Scholar Guild study group led by Andrew Jefford; misty morning in Monbazillac

Winemaker Bruno Bilancini; Wine Scholar Guild study group led by Andrew Jefford; misty morning in Monbazillac

Our tasting started with a dry white wine, 70% Muscadelle and 30% Semillon (2013), named “Andrea” for Luc’s daughter. Unoaked, virtually no skin contact, only a single day of fermentation (no MLF), resulted in a rather flinty but elegant super-dry wine. The centerpiece of the tasting, however, was a trio of sweet wines, all revealing a tangy tangerine note that Bruno said was characteristic of the region. Ranging from light and crisp (young vines) to bold and complex (vines 20-30 years old), these field-blended wines are not intended for dessert! Bruno’s advice was to serve them decanted for as long as two days and quite cold, the lightest (2015 Les Pins) as an aperitif and the more luscious pair (Tirecul La Graviere, bottled spring 2015, and a 1998 Cuvee Madame) with spicy cuisine.

Chateau de Tiregand

Onward to Pécharmant, where the youngest heir to the Saint-Exupéry dynasty met us for a tour of the vineyard, winery and tasting. Cyril is the son (and winemaker in training) of the current winery leader, François-Xavier, who was en route from a trip to Belgium. A bit nervous to lead the presentation for eight wine students and professionals, young Cyril did a fine job walking us through the vineyards, the basics of wine production, and a tasting. (At one point in the cellar, a black cat, heavy with soon-to-be-born kittens, managed to give us all a start as we discussed barrel aging.) Due primarily to its location, Ch. de Tiregand specializes in blends of traditional Bordeaux varieties: Cabernet Sauvignon, Merlot, Cabernet Franc, and Malbec, as well as Sauvignon Blanc, Semillon and Muscadelle. Our walk through the vineyard revealed vines heavy with nearly ripe grapes, sweet and juicy to the taste until met with the crunch of a still-green pip. The date for harvest will be soon, but had not yet been selected.

Cyril Saint-Exupery; Cabernet Franc nearly ready for harvest; busy preparations in the winery.

Cyril Saint-Exupéry; Cabernet Franc nearly ready for harvest; busy preparations in the winery.


South America’s (Wine) MVPs


My first wine tour of South America begins today. In every region, everywhere in the world, there are always a critical few people who lead the shift from bulk to quality wines, and show the pathway into global markets.

Absent major political and economic deterrents, it’s true that winegrapes can grow reasonably well without much human intervention. Many would argue that less is more. But personal touches matter, especially today because we know so much about terroir, agriculture, chemistry and other key process factors. Selecting a good site, planting grapes well suited to that site, nurturing the vineyard through Mother Nature’s life cycles, healthy practices in the vineyard and during winemaking operations, and knowing when to pick in good conditions and bad. These are all human decisions that make a difference in the quality of finished wine.

Every New World country was propelled onto the global stage by a late 20th  century catalyst. The infamous 1976 “judgment of Paris” was a dramatic turning point for wine development in the U.S. In 1994, the end of South African apartheid unleashed 25 years of private entrepreneurship for white and black owners. New Zealand found its international magic in ideal growing conditions for Sauvignon Blanc. Australia overcame a poor reputation owing mostly to a glut of sweet and fortified wines, first by grubbing up vines and later by investing in production technology and enforcing quality standards. At various points during a twenty-year period (1970s-90s), key individuals in South America made the dramatic moves that reset the game board for quality winegrowing in Argentina, Brazil, Chile and Uruguay. (This same story can be told about some European countries, notably Spain, which took great advantage of advances in equipment, technology and labeling regulations to restore eminence to an historic wine producing reputation.)

Without further ado, introducing South America’s “Most Valuable Pioneers” (MVPs), a small collection of the most influential people who helped to propel the “big four” countries into the modern era of the global wine trade!

Clockwise from upper left: Ana, Susana and Jose Balbo; Nicolas Catena; Miguel Torres; Aurelio Montes Jr. & Sr.

Clockwise from upper left: Ana, Susana and Jose Balbo; Nicolas Catena; Miguel Torres; Aurelio Montes Jr. & Sr.

Only one in ten winemakers in South America is female. The grand dame is most certainly Susana Balbo who has dominated the wine scene in Argentina for more than 35 years. In 1981, she was the first woman to graduate from the school of oenology in Mendoza. She has served three times as elected president of the trade group Wines of Argentina. Launching her own winery in 1999 in the Luján de Cuyo region, and recently joined by her two children, Balbo makes three ranges: “nosotros” single vineyard 100% Malbec, signature reserve, and crios (“children”).

The undisputed patriarch of fine wine in Argentina is third generation winemaker Nicolás Catena Zapata, widely credited with reviving Argentina’s industry in the 1990s. Among his revolutionary moves was to hire renowned international consultants, including Paul Hobbs and Michel Rolland, to share their deep knowledge with winemakers in and around Mendoza. For example, they pioneered extended maceration and use of new oak barrels in Argentina. Catena was named “Man of the Year” in 2009 by Decanter Magazine. His daughter Laura joined the family enterprise in 2001 to manage R&D, and the next year created Luca Wines named for her oldest son – a 5th generation on the way?

Antonio and Rinaldo dal Pizzol are considered to be leaders of the boutique wine movement in Brazil since 1974, focusing on direct sales to customers (consumer and trade) rather than large-scale production. Even today, the Dal Pizzol winery sells more than half its wine independently without distributors.

Reinaldo de Lucca is the current generation of an Italian immigrant family that began making wine in Uruguay in the 1940s. He was one of the leaders of the so-called “reconstruction” of the wine industry at de Lucca winery 20 years ago. With multiple wine-related and business degrees from prestigious higher education institutions around the world, he is one of the most highly trained winemakers, certainly in Uruguay, and perhaps in South America. Enjoy Alder Yarrow’s recent Vinography post sharing his October visit to de Lucca winery.

Although his influence was felt a full century before the modernists in this blogpost, no story about MVPs would be complete without Don Pascual Harriague. He is credited with bringing the Tannat grape to Uruguay in 1870 from the Basque region near the Pyrénées, specifically Madiran. Today, Tannat is the signature grape of Uruguay, occupying nearly 50% of all vineyard area.

Adriano Miolo is Brazil’s largest grower and producer of fine wine. According to Evan Goldstein in “Wines of South America,” Miolo is the Catena of Brazil in his “visionary outlook and focus on quality” and is known for pioneering new winegrowing areas such as Campanha Gaúcha. Miolo Wine Group, formed in 2006, has assembled more than 100 products from national and international partnerships, including 8 wine projects in Chile, Argentina, Portugal and Spain (in addition to Brazil).

Aurelio Montes is a pioneer and the modern patriarch of quality wine in Chile. With three other partners, in 1988 Montes founded the winery originally called Discover Wine. Soon their Cabernet Sauvignon wines, rebranded as Montes Alpha, were being sold in 100 countries worldwide. Other growing regions, vineyards and varietal wines soon followed, and are widely considered benchmarks for quality Chilean wines. Iconic wines include Montes Alpha M, Montes Folly and Purple Angel. Son Aurelio Montes, Jr., runs Kaiken, a premium winery established in Argentina in 2002.

Continuing the Spanish tradition of exploring the new world and building on three centuries of family winemaking in the Penedès region of Spain, Miguel Torres “discovered” Chile in 1979. He declared it a viticultural paradise. Looking back 35+ years, Torres considers that initial foray to be stage one of a decade-long journey that helped to catapult Chile’s international reputation starting in the mid-1990s. The hallmarks of a second stage of development included identifying new growing areas, planting additional vines, and taking advantage of viticultural technology. Today the Torres empire includes nearly a dozen brands in Chile.

Clockwise from upper left: dal Pizzo brothers; de Lucca; signature Tannat wine; Morio

Clockwise from upper left: dal Pizzol brothers; Reinaldo de Lucca; signature Tannat wine; Adriano Miolo

Andes photo courtesy of

Balbo, Catena, Montes and Torres photos courtesy of;,,

dal Pizzol, de Lucca, Miolo and Don Pascual wine bottle photos courtesy of,,,


South America’s Big Four: Argentina, Brazil, Chile & Uruguay

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Contains Sulfites

Consumer warning: this is a lengthy article debunking the myths and legends of sulfites.

Let me cut to the chase and provide dessert before the entrée: unless you are asthmatic or one of the 1% club of people who have a bone fide sulfite allergy, it is highly unlikely that sulfites are the cause of your hangover or any other ill effects from drinking wine.

I will make this hypothesis: you like high alcohol wines, you perhaps drink too much wine in one sitting, and/or you tend to mix types of alcohol (including types of wine) in the course of an evening or event. Gotcha! Those choices are the real culprits. Oh yes, and if you think that red wines cause extra problems because of sulfites, you should know that they tend to have lower levels than white or sweet wines. And your theory about European wines having fewer sulfites because you can drink them without ill effects? As a general notion, it’s just not true. Wine made in Tuscany and sold in Italy is the exact same wine that is exported to the U.S. There’s only one difference in the U.S.: the bottle has the required warning “Contains Sulfites” on the back label.


Intrigued? Read on.

This is a complex topic, and I am keen to help simplify it. I cannot be the only reasonably well-educated wine-lover to get confused by the differences among sulfur, sulfur dioxide and sulfites, or about their health effects. Do they matter in the winemaking process? Sure, but why and how? Why is it that sulfites get blamed for many maladies and keep otherwise enthusiastic sippers away from vino?

For wine enthusiasts not terribly intrigued by the chemistry of wine, this analysis may be a bit of a rat-hole. But let’s level-set the chemistry backdrop.

Sulfur (or sulphur) is the tenth most abundant chemical element in the universe. Usually found in salt deposits, it is pale yellow, odorless and brittle. Because it existed naturally near volcanoes such as Pompeii, sulfur was known and used as a preservative in the winemaking process in ancient Roman times, but it was not officially named a chemical element until the 1770s.

Sulfur dioxide (SO2) forms when fossil fuels (e.g., coal, oil) are burned or sulfur-rich mineral ores (e.g., copper, zinc, lead, iron) are smelted. It can be deadly in high concentrations. Commercial SO2 is typically used as a bleaching agent, solvent, disinfectant and refrigerant. SO2 is also used to preserve fresh foods and as a preservative ingredient in processed foods such as jam, soda, canned soups and dried fruit.

dried fruit

Sulfite is a class of sulfur compounds. Because SO2 is one of the best known sulfur compounds, the terms “sulfur dioxide” and “sulfite” tend to be used interchangeably (and thus constitute the main source of consumer confusion).

To simplify things for the balance of this article, I am going to use primarily the compound name SO2 rather than the class name of sulfites. Please hang on to the truth that they are often used interchangeably (and at times incorrectly) in many references as one and the same.

Where does SO2 come from? Two sources: yeast and the winemaker. Some yeast is wild. It may be found in the vineyard on grapes and in the winemaking facility. Most commercial strains of yeast produce 10-30 ppm of SO2 during the normal process of alcoholic fermentation.

Why is SO2 added during the winemaking process? SO2 is considered to be the most important additive used in making wine. As author Jamie Goode describes it in the second edition of his book Wine Science, sulfur dioxide is the “chemical custodian” of wine. (I highly recommend this book as an excellent resource for both consumers and professionals, as it is written in a very approachable style.) SO2 acts a preservative in wine just as it does in solid food. It is both antimicrobial (kills bacteria and fungi) and antioxidant (inhibits the damaging effects of oxidation). The degree to which SO2 exists in finished wine is expressed as “parts per million” or ppm for short. (This is the exactly same liquid measure as milligrams per liter, or mg/l.)

Wine is inherently volatile due to many changes that occur from grape to glass. It can easily spoil from bacteria, turn to vinegar, or develop other faults during fermentation and aging. In Roman times, sulfur-based candles were burned in amphorae (aging vessels). This unnamed discovery stabilized and preserved the wines which were so popular two millennia ago. In modern times, winemakers employ a similar burning process, using SO2 to clean barrels. Sulfur dioxide is increasingly used to augment good cellar practices as part of a winery’s “housekeeping” regime to clean hoses, fermentation tanks, valves and other processing hardware.

When is SO2 added? SO2 is often added to protect and preserve the wine’s character, flavor and color. Among other things, it inhibits enzymes that cause browning, controls the balance of bacteria, controls wild yeasts from growing, helps to extract pigment making red wines “redder,” and prevents secondary fermentation in the bottle. The winemaker’s challenge is to use SO2 judiciously.

Sulfur dioxide can be added at four main stages in the winemaking process depending on the condition of the grapes and desired style of the finished wine:

  1. Arrival of fresh grapes to control wild yeasts and/or to protect the berries from disease as the surface is broken in the process of destemming and crushing the grapes.
  2. Beginning of alcoholic fermentation to prevent browning from oxidation and premature malolactic fermentation (MLF) for fruit-forward wine styles that are not intended to be barrel-aged.
  3. After MLF to achieve certain wine styles, and to preserve and stabilize the wine for barrel aging.
  4. Prior to bottling to support bottle aging.

How much SO2 is added, and why? What factors influence this decision? Two main factors influence how much SO2 should be added at any stage in the winemaking process to achieve antimicrobial and antioxidant goals. The proper conventional dose of SO2 is determined by a technical formula that maximizes the effects of SO2 in the context of alcohol by volume (abv) and pH level.

Alcohol by volume (abv) is the total percentage of ethanol (the type of alcohol in wine) expected in the finished wine. This measure matters because the higher the abv, the less SO2 protection is required. There is no longer a threat of secondary fermentation in the barrel or bottle, and ethanol enhances the bacteria-killing effects of SO2.

The pH scale, which ranges from 0-14, measures acidity (0-6) vs. alkalinity (8-14). Seven is considered neutral. The higher the pH, the more SO2 needs to be added to prevent MLF, Brettanomyces or other bacteria. Acidity (low pH) helps to keep those things under control.

While it may seem counterintuitive, for a quick mnemonic, remember these ratios. It is these ratios that matter.

  • higher pH = lower acidity (which needs more added SO2)
  • lower pH = higher acidity (needs less added SO2)
  • higher alcohol (and drier wine) = less need for SO2
  • lower alcohol (and sweeter wine) = more need for SO2

White wines tend to be higher in acidity than red wines, so applying this ratio, they should require less SO2. But that’s not usually the case. They actually require more SO2 because they are prone to oxidation. The more color in the grape pigment, and the longer the period of maceration (contact with skins and stems), the less added SO2 is needed. In most cases, red wines do not even need to have SO2 added because they contain these natural antioxidants, but conventional winemakers may still add it as a precaution. Additionally, higher pH wines (alkaline) made from very ripe red fruit to enhance youthful drinkability are more susceptible to bacteria, thus may require excessively high levels of added SO2. Wines with higher levels of residual sugar need more SO2 to prevent secondary fermentation. The typical order from most-to-least use of SO2 is as follows: sweet white dessert wines, blush and semi-sweet white wines, dry white wines, and dry red wines.

What happens to SO2 during the winemaking process?

The basic formula for sulfur dioxide in wine is this: total SO2 = bound SO2+ free SO2.

When SO2 is added to wine, it is initially “free” to serve intended antimicrobial and antioxidant purposes. Over time, a portion of the SO2 binds (or dissolves) with other components of the wine and is becomes inactive, undetectable to most people except the small percentage who are genuinely sensitive. Some proportion of the SO2 evaporates as gas, but the unbound portion remains “free,” continuing to work as an antimicrobial and antioxidant agent. Of the total SO2 in finished wine, 50-90% tends to be bound. The remaining 10-50% is active, or free. It is the only portion of the original dose of SO2 still actively working in the wine, and is thus the component most likely to have a negative impact on sulfite-sensitive wine drinkers.

Labeling Laws and Consumer Protection

It’s a conundrum. Labels are frankly not helpful. But how would a consumer know any of this?

All bottles of wine sold in the U.S. with more than 10 ppm of SO2, regardless of country of origin, must be labeled “Contains Sulfites.” By now you should be quite clear that this information borders on irrelevance. All wines will have at least this level of SO2, whether naturally from yeasts or added by winemakers. It simply isn’t a helpful warning.

In the United States, the Food & Drug Administration discovered nearly 30 years ago that about 1% of the population is severely allergic to sulfites, and that about 5-10% of people who have asthma are prone to having adverse effects from sulfites. This prompted the health warning label “Contains Sulfites” starting in 1987.

Why you may ask? Other countries do not do this. For example, SO2 limits vary in the European Union according to type of wine, from 160 ppm for red wine to 400 ppm for sweet wine, but the EU does not require this information to be disclosed on bottles sold/purchased in the EU.

My recommendation is to create a worldwide standard for sulfite content and labeling requirements that actually achieve the intended goal of health protection and education for the consumer. The warning “Contain Sulfites” is neutered by so many misunderstandings of its meaning.

The Bottom Line

If you are one of the rare people with a known sulfite allergy, or if you suffer from asthma plus sulfite sensitivities, please be careful. If you are not certain, do check with a physician who understands the nuances of this type of allergy. Sulfite reactions induce symptoms such as hives, itching, swelling, nausea, diarrhea and low blood pressure. Headaches and hangovers are another matter.

Choosing your wines carefully is another option. If you are particularly sensitive, look for “no sulfites added” on the label. Know your winemaker and his/her practices. (Ask if you aren’t sure – many winemakers can tell you the amount of sulfur dioxide added or the total ppm of SO2 in the finished wine.) Organic wines typically limit SO2 to 110 ppm or less, a good option for people with sulfite sensitivities. Biodynamic wines go a step further, typically building on organic farming and winemaking practices. This class of “natural” wines is an interesting subject unto itself.

And get to know your wine merchant. There’s no substitute for good advice in buying wine.

For everybody else? Don’t drink too much, choose wines that have a low-to-moderate alcohol level, and don’t mix too many different types of alcohol. Don’t buy cheap wine that may have been heavily processed unless you know how the wine was made. If SO2 is an aromatic annoyance, decant and chill the wine before serving. Wines served at warmer temperatures tend to release their free SO2 compounds, which can also be mitigated by chilling and decanting.

In Pursuit of More Knowledge

For another angle on this topic, please read the Vino Ventures blog post from July 2013 “I Can’t Drink Wine. It Gives Me a Headache.” In coming weeks, there will be more posts about natural wine trends, an exploration of various types of wood and toasts used in barrels for aging, and other influences on the overall wine experience.

The references used for this post are primarily secondary based on quality original source material.

  1. Butzke, Christian. “Use of SO2 in High-pH Wines.” Purdue University Extension. March 2010.
  2. Good, Jamie. Wine Science: The Application of Science in Winemaking, Second Edition. Octopus Publishing Group Ltd (Mitchell Beazley), 2014.
  3. Henderson, Pat. “Sulfur Dioxide: Science Behind this Anti-microbial, Anti-oxidant, Wine Additive.” Practical Winery & Vineyard Journal. Jan/Feb 2009.
  4. Jancou, Pierre. “Sulphites in wine.” Undated.
  5. Miller, Mike. “How SO2 and pH are Linked.” Undated.
  6. Robinson, Jancis et al. Oxford Companion to Wine.
  7. “The Bottom Line on Sulfites in Wine.” January 15, 2014.

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