A blanc de noir
Genetics is what really intrigued me about this issue’s variety. Ever since Watson and Crick discovered the double helix of DNA and unraveled its codes, scientists of many disciplines have sought out to map genomes. In the plant world, breeders have sought to genetically select for the biggest, the best, the most drought-tolerant, the most cold-tolerant, and the most disease-tolerant hybrids using the best characteristics of the parent varieties.
I was fortunate to be involved with some of the most advanced breeding programs for grapes in my former career. While I wasn’t the one doing the breeding, I was the one making the wine from the fruits of their efforts. These wines were subsequently judged by various panels to deem if the quality of the wine produced from the fruit was worth that hybrid moving to the next round.
I became involved in the grape breeding process five to six years after a new variety started as a first seedling. So there was a lot of pressure to make the best varietal wine from each specific hybrid. When I first started with the breeding team, my job was explained and I was told, “just make the best wine possible and your first fruit (about 50 lbs./23 kg or so) will be here next Tuesday.”
My first experimental variety was a cross of two white grapes . . . and this happened to be the first load of fruit of the season, so my excitement to perform my new winemaking role ran sky high. I prepared the cellar for a white grape crush and press. When the fruit arrived, I questioned its color — why was it red?! How did this happen? Was it an anomaly? No, it was simply genetics. Today’s variety, Cabernet Doré, is a story about genetics and wine, of course.
Cabernet Doré’s Background
Cabernet Doré (pronounced Dor-ay) is a white grape, opposite of the aforementioned example. How this occurs is that almost all grape varieties are inbred extensively and carry recessive genes from many different forbearers. The parents are two well-known varieties, Cabernet Sauvignon and Norton (listed as Cynthiana in some databases). Both parents have white grapes in their lineage, that being Sauvignon Blanc, and likely an unknown Vitis sp., respectively.
Because each seed in a cluster of grapes is genetically slightly different, Cabernet Doré’s sibling is Crimson Cabernet. It is a relatively young variety in the hybrid field, the first cross being made in 2001 and the patent applied for in 2007 (USPP20, 915 P3). The breeder was Lucian W. Dressel, who lists his address on the patent form as Carrollton, Illinois, but also has ties to one of the most famous and pioneering grape breeders, Dr. Harold Olmo, who had a long career at UC-Davis and mentored countless breeders in his career.
With the variety a relative newcomer in the world of grapes compared to some of the Old World varieties like Chardonnay or Sauvignon Blanc, it will take time to catch on with those growers and winemakers in the regions that is was bred for. It is reported to be growing in 32 of the 50 states here in the U.S., from Minnesota to Texas and Maine to California, primarily in states east of Colorado and clustered around Illinois where Dressler first established it.
A challenge to catching on in the marketplace is the fact that there are so many other good hybrids out there that name recognition comes slowly. And that was always discussed as a stumbling block in the breeding program I worked with. When the final selections are launched in the public, they are touted as a great winemaking grape with characteristics for where they should be grown and why they were grown there. Cabernet Doré has an advantage over some others in this department in that it is like its better-known grandparent — Sauvignon Blanc.
In The Vineyard
It is reported to propagate moderately well from cuttings. It has an abundance of tendrils and easily adapts itself to various wire-training systems. Bud break and flowering is fairly late and it generally sets a moderate crop. The berries are small to medium in size with a waxy bloom at maturity. It is a fairly vigorous vine when grown in fertile soil (but not as vigorous as Norton) so space should be given between vines and rows. Ten-by-eight plantings was recommended in the original patent, which means 10 ft. (3 m) between rows and 8 ft. (2.4 m) between vines in each row. But your soil vigor will dictate what is best in your vineyard.
It has excellent cold hardiness, disease resistance, good productivity, and does not need to be grafted. The harvest parameters I found reported were Brix in the 23 °B range, pH ~3.4, and a relatively high TA of 8.7 g/L. While this may be a perfect start for a dry white wine, your own local growing conditions and seasonal variations will be your limiting factors. With a fairly late flowering, hoping for a warm, sunny fall to hasten ripening is everyone’s dream with this variety.
In The Winery
The fruit can be fermented to produce dry white wines with a Sauvignon Blanc-like character. Depending on your equipment, typically you should destem then crush the fruit and then transfer to your press to extract the juice. For smaller lots, remove the berries by hand and then transfer them to a press bag (like a muslin bag found commonly in use in homebrewing) and lightly squeeze, collecting the juice.
Once the juice has been extracted, you can travel down two different paths. The first option is to cold-settle the juice, rack, and then ferment with your favorite white wine yeast. The other is to skip the cold-settling process and move directly to fermentation. The former wine will produce a crisp dry white wine, pale and straw in color, the latter having more golden hues from the solids contact and perhaps more herbaceous characters. I generally recommend to cold-settle, but that is a stylistic choice and one you need to make on your own.
One thing you will not get is the flavor associated with the Native American grapes in its lineage. It would be a winemaker’s choice, based on initial taste assessment of the newly fermented wine, to conduct a partial or complete malolactic fermentation (MLF). In any case, Cabernet Doré would benefit from short aging on the lees, with or without stirring, and bottling after a few months.
I have recently been experimenting with using a touch of French oak with some Sauvignon Blanc-based wines. Having not been a fan of moderate to heavily oaked white wines and the micro-oxygenation process associated with them, I was turned onto a brand new François Frères 30-gal. (114-L) barrel. With these smaller barrels, the interior surface area-to-wine volume ratio is increased, which can lead to faster extraction of the primary characters of the new oak barrel, like cream, vanilla, and butterscotch. My goal was to get some subtle oak characters that could be blended back into the all-stainless steel for a “fumé” character reminiscent of the same styled Sauvignon Blanc wines made popular by Robert Mondavi in the 1960s and 70s.
Cabernet Doré produces golden-yellow white wines with aromas of pineapple, papaya, banana, and delicate Muscatel. With some oak contact you can enhance the creaminess of the body, with a little mouthfeel and complexity that is slightly reminiscent of butterscotch and vanilla. The use of oak cubes and staves should also achieve similar benefits. As always, I caution to use these adjuncts carefully, in that the same relationship of surface area-to-wine volume applies. Many manufacturers will put the recommended usage and time interval on their packaging. Using a higher dose rate may achieve faster results, but a lower dose rate may not achieve those same results, since the extractable flavors could be depleted. This is the craft of winemaking, some call it art.
A final thing of note that I found in my research for this article is that Cabernet Doré was one of the fastest ever commercial releases for a new hybrid variety. As previously mentioned, the first seedlings that come out of the breeding process take about 5–6 years to produce enough fruit for trial winemaking (then there is all the work that goes into the seedlings in the same trial that did not make the cut). Cabernet Doré and its sibling, Cabernet Crimson, succeeded and showed enough promise to get that patent expedited. The stars were aligned with this one. Try it if you can, I think you’ll like it!
Cabernet Doré Yield 5 gallons (19 L)
- 125 lbs. (57 kg) Cabernet Doré fruit
- Distilled water
- 10% potassium metabisulfite (KMBS) solution (Weigh 10 grams of KMBS, dissolve into about 75 milliliters (mL) of distilled water. When completely dissolved, make up to 100 mL total with distilled water.)
- 5 g Lallemand QA23 yeast (or a favorite white wine yeast)
- 10 g Fermaid K (or equivalent yeast nutrient)
- 5 g Diammonium phosphate (DAP)
- 6-gallon (23-L) plastic bucket
- 6-gallon (23-L) carboy
- 5-gallon (19-L) carboy
- Racking hoses
- Inert gas (nitrogen, argon, or carbon dioxide)
- Refrigerator (~45 °F/7 °C) to cold settle the juice
- Ability to maintain a fermentation temperature of 55 °F (13 °C)
- Pipettes with the ability to add in increments of 1 mL
Step by step
- Crush and press the grapes. Do not delay between crushing and pressing. Move the must directly to the press and press lightly to avoid extended contact with the skins and seeds.
- Transfer the juice to 6-gallon (23-L) bucket. During the transfer, add 16 mL of 10% KMBS solution (This addition is the equivalent of 40 ppm SO₂). Move the juice to the refrigerator.
- Let the juice settle at least overnight. Layer the headspace with inert gas and keep covered.
- When sufficiently settled, rack the juice off of the solids into the 6-gallon (23-L) carboy. Leave some headspace for expansion during fermentation.
- Add Fermaid K or a similar yeast nutrient.
- Prepare yeast. Heat about 50 mL distilled water to 104 °F (40 °C). Do not exceed this temperature as you will kill the yeast. Sprinkle the yeast on the surface of the heated water 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 juice. You do not want to add the yeast to your cool juice if the temperature difference exceeds 15 °F (8 °C). Acclimate your yeast by taking about 10 mL of the cold 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. When the yeast is ready, add it to the carboy
- Initiate the fermentation at room temperature ~(65–68 °F/19–20 °C) and once fermentation is noticed, (~24 hours) move to a location where the temperature can be maintained at 55 °F (13 °C). If using the refrigerator, be sure to monitor your fridge temperature as some older models can be too cold even at the warmest temperature. If your fridge is too cold (colder than 55 °F/13 °C), consider placing the carboy in an ice bath and add ice to the water as needed while monitoring the temperature. If your refrigerator is dedicated to winemaking, there are some aftermarket temperature controllers that can be wired in.
- Two days after fermentation starts, dissolve the DAP in as little distilled water required to completely go into solution (usually ~ 20 mL). Add directly to the carboy.
- Normally you would monitor the progress of the fermentation by measuring Brix. One of the biggest problems with making white wine at home is maintaining a clean fermentation. Entering the carboy to measure the sugar is a prime way to infect the fermentation with undesirable microbes. So at this point, the presence of noticeable fermentation is good enough. If your airlock becomes dirty by foaming over, remove it and clean it and replace as quickly and cleanly as possible. Sanitize anything that will come in contact with the juice.
- Leave alone until bubbles in the airlock are appearing at a rate of about one bubble per minute.
- After about two to three weeks it is time to start measuring the sugar. Sanitize a wine thief; remove just enough liquid to use for your hydrometer. Record your results. If the Brix is greater than 7 °Brix wait another week before measuring. Discard the juice. If the Brix is less than 7 °Brix; begin measuring every other day.
- Continue to measure the Brix every other day until you have two readings in a row that are negative and about the same. This should be -1.5 °Brix or lower for a dry wine.
- Taste the wine for dryness and overall acidity balance. If it is too tart, consider a malolactic fermentation. Move to the next step when desired results have been met.
- When appropriate, rack to the 5-gal. (19-L) carboy and control for headspace. Add 16 mL 10% KMBS solution, lower the temperature, ~45 °F (7 °C).
- Let the lees settle for about 2 weeks and stir them up. Repeat this every 2 weeks for eight weeks. This will be a total of four stirs. This is called the bâttonnage. You’re doing this to enhance the mouthfeel. The whole process is called sur lie aging.
- After the second stir, check the SO₂ and adjust to 30–35 ppm free.
- Let the lees settle. At this point, the wine is going to be crystal clear or a little cloudy. If the wine is crystal clear, that is great! If the wine is cloudy, then presumably, if you have kept up with the SO₂ additions and adjustments, temperature control, kept a sanitary environment, and there are no visible signs of a re-fermentation, then this is most likely a protein haze. If you choose to, you can fine with bentonite to clarify.
- While aging, test for SO₂ and keep maintained at 30–35 ppm. Titratable acidity (TA) target is about 6.5 g/L. The pH target is around 3.4–3.5, but rely more on the TA as that contributes to mouthfeel. You do not want an overly acidic (by mouth) wine.
- Once the wine is cleared it is time to move it to the bottle. This would be about six months after the onset of fermentation. If all has gone well to this point, given the quantity made, it can probably be bottled without filtration. Your losses during filtration could be significant. That said, maintain sanitary conditions while bottling and you should have a fine example of a clean, creamy Cabernet Doré wine. Enjoy!