Cabernet Sauvignon: The king of red wine grapes

There are two important keys to determining the success of any grape varietal. The first key is its adaptability to the local climate where it is planted. We have discussed in this column how many varietals are better suited to either cooler or warmer climates, and rarely is both true for the same varietal. The second key, and probably the trump card in this circumstance, is that the wines produced from any given varietal must be marketable as a varietally-labeled wine or as a significant blending component. Worldwide there are very few varieties that can rise up to these challenges. Cabernet Sauvignon, the most noble of all grapes, is one varietal that can meet those challenges.

Because of its adaptability and marketability, Cabernet Sauvignon has risen to a high level of prestige and prominence in the international wine community, and it is an internationally recognized grape that has held a market share in every major wine growing region of the world.

Cabernet Sauvignon is known for making some of the world’s most robust red wines. The grape was originally thought to be a descendant of the ancient Roman variety Biturica. Given its notoriety, you might think this grape has a long history, but that is not to be the case. Cabernet Sauvignon is native to France and — surprisingly — has only been recorded as growing in the Bordeaux region since the 17th century. DNA analysis performed at UC-Davis in the 1990s confirmed that the variety is the progeny of Sauvignon Blanc and Cabernet Franc. It was very likely the result of a chance pollination as mixed cultivars were grown side by side in vineyards at that time. I am still amazed at how these kinds of chance pollinations are discovered. The seed from that single grape had to have been deposited in the soil in some way and then germinated to develop into a full fruit-bearing plant. The odds of that happening, followed by the grape becoming the second most popular grape in the modern world, has to be staggeringly high.

In Bordeaux, Cabernet Sauvignon is predominantly grown on the left bank of the Gironde, specifically in Graves, the Médoc and Pauillac. It was once widely planted on both the left and right banks, but over the years winegrowers in the region determined which soil types the grape preferred. The limestone and gravel based soils of the left bank are best for the variety and thus plantings on the right bank shifted away from Cabernet Sauvignon. On the right bank, in St. Émilion and Pomerol, red blends now consist primarily of Merlot and Cabernet Franc, while Cabernet Sauvignon is a distant third in popularity. While Cabernet is the talk of Bordeaux, Merlot is gaining popularity — even on the left bank — as it ripens two to three weeks in advance of Cabernet on average, which can be very important in the region. However, Cabernet is still the predominant component in the first growths with better than 75 percent of the blend. The one exception being Chateau Haut-Brion, where it is only present as about half of the blend component. There are about 6,000 producers of Cabernet or Cabernet-based blends worldwide. In the United States alone there are about 750 producers. Therefore you can find a Cabernet or Cabernet-based blend in just about every price point of wines sold worldwide.

Bordeaux produces 60% of the Cabernet Sauvignon grown in France. Plantings also exist in the Loire, Midi and Provence, which produce lighter styles of Cab as well as rosé styles. There are many good vin de pays in the Languedoc, where it is produced as a varietal rather than a blend. It all depends on who is writing the review, but many wine drinkers have been led to believe that the best Cabernets come from Bordeaux. However, The Judgment of Paris wine competition in 1976 swayed many opinions in the international wine world about Cabernet’s reign in Bordeaux and the rest of France. That year Cabernet wines from the Napa Valley in California scored comparatively to similar wines from France, signaling that France had an up and coming rival.

Today the acreage of Cabernet in California is about equal to that of Bordeaux at about 75,000 acres, and it is grown in all of the state’s reporting wine districts. Fruit quality in the Napa Valley is considered superb and many high quality wines are produced there. Some of the wines have even achieved cult status and sell in excess of $1,000 for a 750-mL bottle. Alas, not all the wines produced in the Napa Valley cost that much, but bottle prices of $50-100 are the norm. In 2010, not a good year by California standards, the Napa Valley (District 4) crushed 50,487 tons, more than every grape reporting district except the northern San Joaquin Valley (District 11) which crushed more than 96,000 tons. District 11 incorporates much of the fruit into varietal wines by companies including Constellation Wines, Gallo and Bronco Wine Company, who sell at price points from $7–$17 per bottle. The high quality of the fruit commands high price per ton, and most prices range between $4,000–$8,000 with a range of $1,000 to $50,000 per ton in District 4. Compare that with $200–$1,800 per ton in District 11. I find District 11 and Languedoc wines very affordable and drinkable, which lends to the testament of the universal nature of Cabernet Sauvignon. Because of its adaptablity, Cabernet thrives all over the world, most notably in the Maipo Valley of Chile, as well as Coonawarra in Australia and the Okanagan Valley of British Columbia. It is also an important red wine grape in New Zealand, South Africa and Italy and is growing in popularity in Spain and Portugal.

Cabernet Sauvignon grape clusters are loose with small berries and tough skin, which can contribute to some pretty harsh tannins. It can be a vigorous vine, and vigor is controlled with rootstock choice and proper site selection. Some say that if the Napa Valley had to be planted all over again, it should have been planted on the hillsides where the rocky soils are more effective in controlling vigor. The rocky soils also drain better, much like the soils of the left bank in Bordeaux. When grown on the fertile soils of the valley, tonnage is controlled through green harvesting clusters after veraison. Many winemakers believe that high fruit loads on vines lead to lesser quality grapes, but this is difficult to prove scientifically, primarily in that no one can agree what the definition of “quality” actually is. What is generally agreed on is that ripening of Cabernet is critical and several studies in the last ten years have focused on tannin and flavor maturation. It is a variety that ripens later, requiring more hang time on the vine to develop fruit flavors. This is very important in Bordeaux because the region is more likely to have a shortened growing season. (Thus blends with Merlot and Cabernet Franc help make up some of the shortfalls of ripening). The rules of the Bordeaux AOC dictate yields in order to get the grape to ripen in any given season. These loose clusters can hang long through the growing season, and research has shown that the concentrations of methoxypyrazines in the berries decrease the longer the clusters hang.

Methoxypyrazines are a class of compounds that are responsible for the vegetal characters of green bell pepper — a signature flavor marker that Cabernet Sauvignon and Sauvignon Blanc connoisseurs either love or hate. The concentrations of these flavors are highest at veraison and the compounds are progressively broken down by sunlight as the fruit hangs on the vine. This often leads to the potential for very different styles of wine depending on the vintage.

If you give Cabernet a long time on the vine you will have a very fruit-forward style. Unfortunately, this fruit-forward style also comes with high alcohol levels and low acidities. When I taste wines like this I consider them fat and flabby, and they are dull and do not have much prospect for aging. It’s true that wine styles for Cabernet have changed over the years, but winemakers have long known about how best to ripen the grape. A number of years ago we made an interesting discovery in the wine cellar at UC-Davis: a treasure trove of vintage 1980 Cabernet Sauvignon wines from appellations that included Napa Valley, Sonoma, Anderson Valley, Central Coast, the Sierra Foothills and a few others. There were 24 different producers in all. Of course we had to create an opportunity to taste through them, which fell under the guise of “research.” The common component between the wines is that they had been cellared under identical conditions for more than 25 years. First of all, there was not an alcohol above 14.5%. Most of the wines covered a range of 12.5–13.5% ABV. Two or three had deteriorated badly, specifically those with lower acidities and higher pH values. But the wines that showed the best were low in alcohol; acid/pH balanced, still had a lot of the bright red fruit characters and little in the way of meth-oxypyrazine. Wine styles and techniques have changed in 30 years, and there are now some winemakers hoping to create this distinct style of Cabernet from the past. After all, these are the wines that made Cabernet big in California. The parallel here to Bordeaux-based blends is the ripening and natural acidities of the grapes at harvest.

The tannins in Cabernet Sauvignon can be quite harsh, including powerful sensations of bitterness and astringency. Winemakers are not afraid to barrel down these wines for up to two years to add small doses of oxygen to help polymerize and soften the tannins. Both French and American barrels are used from a number of different coopers. Micro-oxygenation, MOX for short, is a mechanized way to add small doses of oxygen to wines, and this is commonly used to make wines sold for less than $20 per bottle. Some winemakers prefer to use age-old fining techniques with egg whites to craft their perfect cuvée. Blending can also tame tannins. Experienced winemakers prepare their blends when the wine is young to integrate the tannins during maturation. Typical blending varieties include Merlot, Cabernet Franc, Petit Verdot and Malbec. This group is typically known as the Bordeaux blend, and in the United States the same blending schema is used in wines labeled as Meritage.

The rules of blending change from country to country, for example in Italy where Sangiovese rules, Cabernet Sauvignon is used to make Super Tuscans, and in Australia it is blended with Shiraz. In Spain you will find it blended with Tempranillo.

With respect to food pairing, Cabernet Sauvignon invites a hearty meal with protein; steak, prime rib, pork roasts. On its own, the tannin structure, especially in a young wine, can be a bit much on the palate. Thus the proteins in the meat react with the wine tannins to soften the approach in the mouth and help bring out the fruit flavors. The choice is a little more difficult when it comes to trying to pair Cabernet with vegetarian meals, but I would try pizza with red sauce and cheese, or pasta-based dishes with garlic. It also pairs well with cows-milk cheeses, both early ripening and aged. Whatever your desires, given the popularity and abundance of Cabernet Sauvignon grapes, there is sure to be a style you like that you can make yourself.

Cabernet Sauvignon Recipe

(yield: 5 gal/19 L)

Ingredients
• 125 pounds (57 kg) fresh Cabernet Sauvignon fruit
• Distilled water
• 10% potassium metabisulfite (KMBS) solution: Weigh 10 grams of KMBS, dissolve into about 50 milliliters (mL) of distilled water. When dissolved, make up to 100 mL total with distilled water.
• 5 grams Lallemand D254 yeast
• 5 grams Di-ammonium phosphate (DAP)
• 5 grams Go-Ferm
• 5 grams Fermaid K (or equivalent yeast nutrient)
• Malolactic fermentation starter culture (CHR Hansen or equivalent)

Other equipment or needs
• 1 15-gallon (57-L) food-grade plastic bucket for fermentation.
• 5-gallon (19-L) carboy, 1-2 one-gallon (3.7-L) jugs
• Racking hoses
• Crush equipment, destemmer/crusher
• Wine press
• Inert Gas — Nitrogen, Argon or Carbon Dioxide
• Ability to maintain a fermentation temperature of 81–86 °F (27–30 °C).
• Thermometer capable of measuring between 40–110 °F (4–43 °C) in one degree increments
• Pipettes with the ability to add in increments of 1 milliliter
• The ability to measure residual sugar at the completion of fermentation
• Tartaric acid — addition rate is based on acid testing results

Step by step
1. Clean and sanitize all your winemaking tools, supplies and equipment.

2. Crush and destem the grapes. Transfer the must to your fermenter.

3. During the transfer, add 15 milliliters of 10% KMBS solution. (This addition is the equivalent of 50 ppm SO2).

4. Take a sample to test for Brix, acidity and pH. Keep the results handy. We’ll take this up later.

5. Layer the headspace with inert gas and keep covered. Keep in a cool place overnight.

6. The next day sprinkle the Fermaid K directly to the must and mix well.

7. Go back to those lab results you took yesterday. Typical Brix for this style is 24–25 °B. Typical acid levels will be 0.58–0.62%. Adjust as necessary using tartaric acid. If the acid is higher than 0.70%, don’t panic, this recipe calls for a minimum final acidity of 0.55%.

8. Prepare yeast: Heat about 50 mL distilled water to 108 °F (42 °C). Mix the Go-Ferm into the water to make a suspension. Take the temperature. Pitch the yeast when the suspension is 104 °F (40 °C). Sprinkle the yeast on the surface and gently mix so that no clumps exist. Let sit for 15 minutes undisturbed. Measure the temperature of the yeast suspension. Measure the temperature of the must. Do not add the yeast to your cool juice if the temperature of the yeast and the must temperature difference exceeds 15 °F (8 °C). To avoid temperature shock, acclimate your yeast by taking about 10 mL of the must juice and adding it to the yeast suspension. Wait
15 minutes and measure the temperature again. Do this until you are within the specified temperature range. Do not let the yeast sit in the original water suspension for longer than 20 minutes.

9. When the yeast is ready, add it to the fermenter and mix.

10. You should see signs of fermentation within about one to two days. This will appear as foaming on the must surface and it will appear that the berries are rising out of the medium. This is referred to as the cap rise.

11. You need have on hand the ability to push the grapes back into the juice to promote color, and tannin extraction. This is called “punching down” and this should be done three times per day.

12. Monitor the Brix and temperature twice daily during peak fermentation (10–21 °Brix). Maintain a fermentation temperature of 81–86 °F (27–30 °C).

13. At about 19 °Brix, sprinkle in the DAP and punchdown.

14. When the Brix reaches 4 °Brix, transfer the must to your press, and press the cake dry. Keep the free run wine separate from the press portion for now and label the vessels.

15. Transfer the wine to your carboys or 1-gallon (3.7-L) jugs. Your press fraction may only be a gallon or two. Make sure you do not have any headspace. Place an airlock on the vessel(s).

16. Inoculate with your malolactic (ML) bacteria. Check the manufacturer’s instruction on how to prepare and inoculate. Cover the tops with a breather to allow CO2 to escape.

17. Monitor the ML fermentation using a thin layer chromatography assay available from most home winemaking supply stores.

18. When the ML is complete, measure the residual sugar. You are shooting for 0.5% or lower. If the sugar is higher, give it more time to finish fermentation.

19. Add 2 mL of fresh KMBS (10%) solution per gallon of wine. This is the equivalent to ~40 ppm addition.

20. Measure the pH and titratable acidity. Most importantly you want a finished TA of about 0.55 to 0.60%. The pH is secondary but should be around 3.6. Add acid to adjust the TA prior to settling. Place the wine in a cool place to settle.

21. After two weeks, test for SO2, adjust the SO2 as necessary to attain 0.8 ppm molecular SO2. (There is a simple SO2 calculator at www.winemakermag.com/guide/sulfite). Check the SO2 in another two weeks and adjust. Once the free SO2 is adjusted, maintain at this level. Check every two months, and before racking.

22. Rack the wine clean twice over a 6–8 month time frame to clarify. Once the wine is cleared, it is time to move it to the bottle.

23. Blending the wine to integrate the press fraction back into the free run. You may not need it all, use your judgment. Fining with egg whites may be necessary to tame the tannins.

24. Filtration as desired. Consult www.winemakermag.com for tips on fining and filtration if problems are evident. Maintain sanitary conditions while bottling. Once bottled, you’ll need to periodically check your work by opening a bottle to enjoy with friends.