Merzling
Also known as: FR 993-60
Merzling
Summary
Merzling is a pioneering first-generation white PIWI variety developed at the Freiburg Research Institute in Germany, critically important in the history of disease-resistant grape breeding. Released in 1960, Merzling was among the earliest PIWI varieties to achieve meaningful disease resistance while maintaining acceptable wine quality, serving as a proof of concept for the entire PIWI movement. Though less commonly grown as a wine grape today, Merzling’s greatest legacy is as a breeding parent—it is an ancestor of many of today’s leading PIWI varieties and remains foundational to understanding PIWI genetics.
Identity
VIVC: Entry #7843
Berry Color: BLANC
Type: PIWI (Interspecific hybrid - first generation)
Breeding Number: FR 993-60
Creator: Staatliches Weinbauinstitut Freiburg, Germany
Year: 1960
Name Origin: Derived from “Merz” + “-ling” (German suffix for grape varieties, like Riesling)
Genetic Origin
Parentage: Seyval blanc × (Riesling × Pinot gris)
Breaking down the parentage:
- Seyval blanc: French-American hybrid providing disease resistance
- Riesling × Pinot gris: Vinifera cross providing wine quality
Historical Significance: One of the first attempts to combine hybrid disease resistance with vinifera wine quality
Importance as Breeding Parent
Merzling’s genetic legacy is foundational to modern PIWI:
Direct Offspring
| Variety | Cross | Type | Significance |
|---|---|---|---|
| Bronner | Merzling × Gm 6494 | White | Major breeding parent |
| Solaris | Merzling × Gm 6493 | White | Early ripening, popular |
| Johanniter | Riesling × Complex (incl. Merzling) | White | Riesling-like quality |
| Regent | Diana × Chambourcin (Merzling ancestry) | Red | Major German variety |
Grandchildren (via Bronner)
This makes Merzling one of the most important ancestors in PIWI breeding history.
Disease Resistance Profile
| Disease | Resistance Level | Notes |
|---|---|---|
| Downy Mildew | MEDIUM-HIGH | Good for first generation |
| Powdery Mildew | MEDIUM-HIGH | Good for first generation |
| Botrytis | MEDIUM | Some susceptibility |
| Black Rot | MEDIUM-HIGH | Reasonable resistance |
Historical Context: Resistance levels were significant improvements over vinifera, though less than later PIWI generations
Spray Reduction: 50-70% reduction vs. traditional varieties
Distribution
Total Global Plantings: ~100 hectares (declining as wine grape)
| Country | Hectares | Notes |
|---|---|---|
| Germany | ~50 | Origin; limited |
| Switzerland | ~30 | Some plantings |
| Austria | ~15 | Minor variety |
| Other | ~5 | Various |
Trend: Declining as newer PIWI varieties offer better wine quality
Viticulture
Growth Characteristics
- Vigor: Medium to high
- Growth Habit: Semi-erect
- Budbreak: Medium
- Flowering: Mid-season
- Véraison: Medium
- Harvest: Medium-late
Climate Requirements
- Ideal Climate: Cool continental
- Heat Summation: 1,100-1,500 GDD (base 10°C)
- Frost: Moderate tolerance
- Adaptability: Central European conditions
Soil Preferences
- Adaptable: Various wine soils
- Ideal: Well-drained
- Effect: Limited terroir expression
Viticultural Management
- Training: Guyot or cordon
- Pruning: Standard practices
- Yield Control: 70-90 hl/ha
- Spray Program: Reduced vs. vinifera
Enology
Must Parameters at Harvest
| Parameter | Typical Range | Notes |
|---|---|---|
| Brix | 19-22° | Moderate |
| pH | 3.1-3.4 | Moderate |
| Titratable Acidity | 7.0-9.0 g/L | Can be high |
| YAN | 150-250 mg/L | Variable |
Wine Character
- Neutral: Not strongly aromatic
- Clean: Generally free of hybrid character
- Simple: Limited complexity
Fermentation
- Yeast Selection: Neutral yeasts
- Temperature: 14-18°C
- Duration: 14-21 days
- Goal: Clean fermentation
Wine Styles
| Style | Method | Character |
|---|---|---|
| Fresh | Stainless steel | Crisp, neutral |
| Blend | With aromatic varieties | Adds acidity |
| Base | For sparkling | Good acidity |
Aging Potential
- Fresh Style: 1-2 years
- Character: Best consumed young
Sensory Profile
Visual
- Intensity: Pale
- Hue: Greenish-yellow
- Character: Light, clear
Aromatic Profile
| Category | Descriptors |
|---|---|
| Fruit | Green apple, citrus |
| Herbal | Grassy notes |
| Floral | Minimal |
| Other | Neutral, clean |
Palate
- Body: Light
- Acidity: Medium to high
- Alcohol: Low to moderate (10-12%)
- Finish: Short, clean
Quality Assessment
Merzling wines are:
- Clean and acceptable
- Neutral and simple
- Serviceable but not exciting
- Outclassed by later PIWI varieties
Winemaker Considerations
Challenges
- Simple Character: Limited complexity
- Superseded: Better varieties now available
- Declining Interest: Less planted each year
- Quality Ceiling: Cannot compete with modern PIWI
- Marketing: Difficult to position
Opportunities
- Historical Interest: PIWI heritage variety
- Blend Component: Adds acidity
- Breeding Stock: Still valuable genetics
- Low Input: Reduced spray requirements
- Educational: Teaching about PIWI history
Historical Significance
Merzling’s role in viticulture history:
- Pioneer: Proved PIWI concept viable
- Foundation: Ancestor to many modern varieties
- Research Tool: Informed later breeding
- Benchmark: Showed improvement was needed
The PIWI Generation Gap
Understanding Merzling’s place:
| Generation | Example | Wine Quality | Resistance |
|---|---|---|---|
| 1st | Merzling | Acceptable | Good |
| 2nd | Bronner | Good | High |
| 3rd | Souvignier Gris | Excellent | High |
| 4th | Divico | Premium | Very High |
Each generation improved on the previous.
Sources
- VIVC Database - Vitis International Variety Catalogue
- Staatliches Weinbauinstitut Freiburg
- PIWI International Association
- German Wine Institute
- Becker, N. (2000). PIWI breeding at Freiburg. Vitis 39(4). Vitis Journal
Last Updated: January 13, 2026