Vine and Clone Information
Cabernet Sauvignon clone 337
Cabernet Sauvignon clone 337 is a French ENTAV-certified clone that’s widely planted in Bordeaux and now very popular in California for making deeply colored, fruit‑driven, ageworthy Cabernet.[selections.entav-inra +1]
Origin and general profile
• Originates from Bordeaux and is one of the officially selected French Cabernet clones.
• Described by French clonal catalogs as having slightly shorter growing cycle than some other Cabernet clones and being well suited to wines built for ageing.
• Appreciated by growers for reliable agronomic behavior and by winemakers for concentration and structure.
Viticultural characteristics
• Tends to give moderate to good yields rather than being extremely low‑cropping, especially compared with some older “boutique” clones.
• Produces relatively small berries and compact clusters, which increases skin‑to‑juice ratio and boosts color and tannin.
• Often noted as a bit less overtly herbal/pyrazinic than some other Cab clones, which is one reason it’s attractive in warmer New World sites.
Wine style and sensory notes
• Typically yields deeply colored wines with intense dark fruit (blackberry, black cherry, plum) and notable tannic structure.
• Frequently described as lush and fruit‑forward, with a smooth, rounded mouthfeel and chocolate or cocoa notes, especially when paired with new oak.
• Several tasters have commented that clone 337 wines can be very opulent and “chocolaty,” sometimes at the expense of classic leafy/herbal Cabernet typicity.
Example: A Napa tasting of single‑clone wines found 337 to show softer, rounder fruit (more plums than cherries), smooth fine‑grained tannins, and an especially open, fruit‑driven palate compared with clones 4 and 6.[winespecific]
Winemaking and ageing
• Responds well to French or Hungarian oak, which amplifies dark fruit, chocolate and spice, and supports long ageing.
• French technical notes highlight its aptitude for structured wines capable of bottle ageing rather than simple early‑drinking styles.
Practical takeaways for a grower/winemaker
• Good option if you want: small berries, deep color, firm tannin and a modern, ripe, low‑“green” Cabernet profile.
• In warm regions (e.g., Lodi, Central Valley, Paso, Napa), it’s used specifically to produce concentrated, plush Cabernets that still have enough backbone for oak and ageing.
Merlot clone 181
Merlot clone 181 is a French ENTAV‑INRA selection that’s widely used as a “workhorse” Merlot clone, known for good productivity and solid, ageworthy wine quality.[riversun +2]
Origin and general notes
• Clone 181 is an ENTAV‑INRA Merlot clone originally selected in Bordeaux and has been widely distributed internationally since the 1970s.
• In California, a virus‑tested selection is sold as Merlot‑15, which is essentially clone 181 and is popular with many winemakers.
Viticultural behavior
• Shows good productivity with naturally even fruit distribution in the fruiting zone, making crop load easier to manage.
• Produces medium to large, relatively loose bunches, which can help reduce rot risk compared with very tight‑clustered Merlot selections.
• In trials, yield is typically in the “medium” range for Merlot, not as low as some quality‑focused clones but not excessively heavy either.
Ripening and fruit chemistry
• In comparative work, clone 181 tends to be one of the later‑ripening Merlot clones, reaching harvest a few days after other tested clones.
• Consistently shows relatively high total soluble solids (good sugar accumulation), often among the highest in Merlot clone trials, which translates to higher potential alcohol.
• pH and titratable acidity are generally similar to other Merlot clones, so its main distinction is higher sugars rather than very different acid balance.
Wine style
• Wines from clone 181 are described as having good alcohol, color and structure, suitable for both young drinking and ageing, depending on vinification.
• A producer example notes bright red fruit, violets, toasted spice, and good balance of acid and tannin, with clear capacity to age several years in bottle.
• French technical descriptions for Merlot clones with similar parameters emphasize structured, balanced wines that respond well to barrel ageing.
Practical takeaways for you
• Good choice if you want: reliable yield, loose to medium‑dense clusters, high Brix at harvest, and Merlot with enough structure to stand up to oak and some bottle age.
• Because it can run higher in sugar and ripens on the later side, it tends to fit best on moderate‑to‑slightly cooler blocks or with careful crop/load and irrigation to avoid excessive alcohol.
Rootstock 5C
Rootstock 5C (usually “Teleki 5C”) is a Vitis berlandieri × V. riparia cross used where you want moderate vigor, good phylloxera resistance, and cooler‑site suitability.
Parentage and general role
• 5C Teleki comes from a berlandieri × riparia cross, so it leans toward cooler, moister‑site adaptation rather than hot, dry sites.
• Commonly used as a “balanced vigor” rootstock, between low‑vigor options like Riparia Gloire and higher‑vigor stocks like 5BB or Ramsey.
Vigor, rooting and soil fit
• Imparts moderate vigor (often described as moderate to moderately high), making it suitable for sites where you don’t want excessive vegetative growth.
• Performs best on deeper clay/loam soils with decent water‑holding, and is considered a cool‑region rootstock; not recommended for sandy soils in warm regions.
• Root system is relatively shallow compared with some drought‑oriented berlandieri × rupestris stocks, so it is more drought‑susceptible and not ideal for very dry sites without irrigation.
Pest and disease tolerance
• Strong resistance to phylloxera, which is one of the main reasons it is widely planted.
• Listed among rootstocks with resistance to root‑knot nematodes, though not the highest in that regard; suitable where nematode pressure is present but not extreme.
Effects on vine performance and fruit
• Tends to give a relatively low yield‑to‑pruning‑weight ratio: good canopy for the amount of crop, which suits varieties with weaker fruit set.
• On appropriate sites, has a record of producing high‑quality Cabernet in Coonawarra, Chardonnay in cool hills, and Merlot on cooler clay‑loam districts, indicating good balance of vigor and ripening.
• Because vigor is moderate rather than high, it can help manage potassium uptake and canopy density versus some high‑vigor stocks that push pH up and delay ripening.
Practical implications for your context
• Best fit: cool to moderate climates, heavier but well‑drained soils, moderate fertility, with reliable water.
• Risky fit: warm, sandy, low‑water sites where drought and salinity are issues; other berlandieri × rupestris (e.g., 110R, 140Ru, Ramsey) are usually better there.
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