Lees Aging and Bâtonnage Techniques

Problem Definition

Sur lie aging (aging on yeast lees) and bâtonnage (lees stirring) are techniques used primarily in white wine production to develop texture, complexity, and mouthfeel through yeast autolysis. While these techniques can significantly enhance wine quality, they also carry risks including reduction, off-odor development, and Brettanomyces contamination in insufficiently managed environments. Understanding autolysis mechanisms, appropriate stirring protocols, and risk mitigation strategies is essential for successful lees contact programs.

Technical Context

Yeast Autolysis Mechanism

Autolysis is the enzymatic self-degradation of yeast cells after death, releasing intracellular compounds:

Timeline (approximate):

0-3 months: Cell death; limited release
3-12 months: Active autolysis; polysaccharide/mannoprotein release
12+ months: Extended autolysis; amino acid release; complexity development

Released Compounds:

Mannoproteins (cell wall polysaccharides):
- Wine mouthfeel/texture
- Protein stability improvement
- Tartrate inhibition
β-glucans (cell wall):
- Texture/body
- Filtration challenges
Amino acids/peptides:
- Complexity
- Umami character
Nucleotides:
- Flavor complexity
- Yeast-derived aromatics

Factors Affecting Autolysis Rate

Temperature:

Higher temperature (18-20°C): Faster autolysis
Lower temperature (10-12°C): Slower; more controlled
Champagne cellars: 10-12°C for slow, controlled autolysis

pH:

Higher pH: Faster autolysis
Wine pH typically optimal (3.0-3.8)

Alcohol:

Higher alcohol: Faster membrane breakdown
Standard wine levels adequate

Yeast Strain:

Strain-dependent autolysis rates
Some strains selected for autolytic potential

Bâtonnage Mechanics

Purpose:

Resuspend settled lees
Expose lees to wine (accelerate release)
Provide micro-oxygenation
Prevent compaction/reduction

Frequency:

Weekly to monthly (style-dependent)
Burgundy white tradition: Weekly initially, decreasing
More intensive: Fuller texture development

Options and Interventions

Lees Types

Gross Lees (Bourbes):

First settling after pressing
Contains grape solids, tartrates, proteins
Usually racked off within 24-48 hours
Not used for aging (harsh, bitter)

Fine Lees (Lies Fines):

Yeast cells from fermentation
Clean, healthy character
Target for sur lie aging
Selected for quality

Sur Lie Duration by Style

Muscadet Sur Lie:

Minimum 5 months on lees (regulatory)
No racking until bottling
Single vintage

Chardonnay (Burgundy-Style):

6-18 months typical
Weekly bâtonnage initially
Barrel or tank

Champagne (Sparkling):

Minimum 12 months on lees (non-vintage)
Minimum 36 months (vintage)
Extended for prestige cuvées (5-10+ years)
No bâtonnage (riddling only)

Chenin Blanc (Vouvray):

Variable; 6-12 months common
Develops complexity for sweet and dry styles

Bâtonnage Protocol

Traditional (Barrel):

Insert bâton (stirring rod) through bung
Gentle rotation to resuspend lees
Avoid vigorous agitation (oxidation risk)
Duration: 30-60 seconds per barrel

Tank:

Paddle stirrers
Circulation pumps (gentler)
Rotation frequency adjustable

Frequency Schedule:

Weeks 1-4: 2-3× weekly
Months 2-3: Weekly
Months 4+: Monthly to stopped

Risk Management

Reduction Prevention:

Bâtonnage provides micro-oxygenation
Prevents excessive reductive conditions
Releases bound sulfides

Brettanomyces Risk:

Extended lees contact with residual sugar: High risk
Ensure fermentation complete before extended aging
Monitor for 4-EP/4-EG

Volatile Acidity:

Spoilage organism risk during extended aging
Maintain SO₂ protection
Temperature control essential

Trade-offs and Risks

Benefits of Sur Lie Aging

Enhanced mouthfeel and texture
Improved protein stability (natural fining)
Tartrate stability improvement
Complexity development
Oxidative protection from lees consumption

Risks of Extended Lees Contact

Reduction: H₂S, mercaptans if insufficient stirring
Brett contamination in red wines
Off-odors from unhealthy lees
Delayed bottling (market timing)
Filtration challenges (β-glucan clogging)

Bâtonnage Intensity Trade-offs

Intensive bâtonnage:

Fuller texture
Faster autolysis
Higher oxygen exposure
Risk of oxidation if excessive

Minimal bâtonnage:

Leaner style
Slower development
Higher reduction risk
Less oxygen exposure

Practical Implications

Grape Variety Considerations

Chardonnay:

Classic variety for sur lie aging
Develops buttery, toasty notes (with MLF and oak)
Chablis: Less lees contact; mineral focus
Bourgogne: More intensive; richer texture

Chenin Blanc:

Responds well to lees contact
Adds complexity to both dry and sweet styles
Savennières tradition

Sauvignon Blanc:

Limited lees contact (preserve aromatics)
Bordeaux blanc tradition: Brief lees contact
Marlborough: Usually no lees aging

Appellation Requirements

Muscadet Sèvre et Maine Sur Lie:

Regulatory requirement: Minimum 1 winter on lees
Must be in contact with lees at bottling
Specific labeling rules

Champagne AOC:

Minimum 15 months total aging (12 on lees for NV)
Minimum 36 months for vintage
Autolysis character essential to style

Barrel vs. Tank Sur Lie

Factor	Barrel	Tank
Oxygen exposure	Higher (stave permeability)	Minimal
Bâtonnage control	Manual; individual	Mechanical; uniform
Oak influence	Yes	No
Volume	Small lots	Larger volumes
Labor	Higher	Lower

References

Ribéreau-Gayon, P., Glories, Y., Maujean, A., & Dubourdieu, D. (2006). “Handbook of Enology, Volume 2.” Wiley. Publisher Link Publisher Link
Alexandre, H. & Guilloux-Benatier, M. (2006). “Yeast autolysis in sparkling wine.” American Journal of Enology and Viticulture, 57(2), 107-116. DOI: 10.5344/ajev.2006.57.2.107
Feuillat, M. (2003). “Yeast Macromolecules: Origin, Composition, and Enological Interest.” American Journal of Enology and Viticulture, 54(3), 211-213. AJEV Link
Doco, T., et al. (2003). “Influence of sur lie aging on polysaccharides.” American Journal of Enology and Viticulture, 54(3), 150-155. AJEV Link

Last Updated: January 6, 2026