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Physicochemical changes and wine treatments

Course Code:

8.3

Semester:

8th Semester

Specialization Category:

SC

Course Hours:

2Θ + 2Ε

ECTS:

6


Lesson Code: 8.3

Semester: 8th Semester

Category: Compulsory

Hours: 2h Theory + 2h Lab

ECTS credits: 6

 

LEARNING RESULTS

After the end of the course students will be able to:

  • More effective use by the students of the various clarifying agents and their familiarization with the various wine treatment and stabilization techniques.
  • A more rational approach to the concept of aging and a corresponding use of the means required for the best possible guidance of its oxidative phase.
  • Accurate identification & treatment of organoleptic errors & deviations.

 

General Skills

  • Search, analysis and synthesis of data and information, also using the necessary technologies
  • Adaptation to new situations
  • Decision making
  • Autonomous work
  • Teamwork
  • Work in an international environment
  • Work in an interdisciplinary environment
  • Project planning and management
  • Respect for the natural environment
  • Demonstration of social, professional and ethical responsibility

 

COURSE CONTENT

Theoretical part

  1. The concept of Clarity and Colloidal phenomena. The clarity of the wines. The colloidal state of wines. Physicochemical properties of wine colloids. The protective colloids. Use of the Arabic code.
  2. Interventions and manipulations for the clarification & stabilization of wines. “The Collaring”. Generally about treatments. The settling of suspended particles. Role and practice of post-fermentation releases. The theory of wine collaring using proteins. The tannin-protein interaction. The effect of collaring on wine characteristics. The concept of over collaring. The products used during gluing. The collaring technique. The use of bentonite. Various other clarification techniques.
  3. Clarification of wines by filtration and centrifugation. The principle of filtration. The laws of percolation. Assessment of the filterability of wines. Various materials and additives used during filtration. Filtration with diatomaceous earth. Filtration with cellulose acetate plates. Membrane filtration. Tangential filtration. Effects of filtration on the organoleptic characteristics of wines. Centrifugation.
  4. Stabilization of wines by physicochemical methods. Stabilization of wines by heating. The use of industrial refrigeration in stabilization.
  5. The mechanism of crystallization & precipitation of tartaric acid salts. Tests to certify the stability of wines against precipitation of tartaric acid salts. Preventive measures to avoid precipitation of tartaric acid salts.
  6. The ion exchange technique. The application of the electrodialysis technique in winemaking.
  7. Metallic opacities & their treatment: Iron and the mechanism of iron opacification. Copper and the mechanism of copper tarnishing. The heavy metals.
  8. Redox phenomena. General concepts. The redox potential of wines. The factors affecting the redox potential.
  9. The maturation of red wines. The mechanisms of aging. The evolution of the polyphenolic characteristics of red wines during the oxidative phase of aging. The chemical reactions of polyphenolic compounds during the maturation and aging of wines. The reductive aging of red wines. The various processes & handling of wines during the oxidative aging phase. Effect of wood type on the evolution of red wines. Problems that can occur during the oxidative phase of aging.
  10. Origin, nature and consequences of basic organoleptic aberrations. Oxidation errors. The various bacterial infections. The microbial origin and chemical properties of volatile phenols. The smell of cork. The presence of sulfur derivatives and reducing odors. Various other errors & aberrations and how to deal with them.

 

Laboratory Part

  1. Exercise 1st Wine Oxidability Control. (Browning & Pinking test).
  2. Exercise 2 Evaluation of various processing materials in terms of their ability to impart antioxidant protection to wines. (Proteins, SO2, PVPP).
  3. Exercise 3 Protein blur. (Bentotest – Heat test).
  4. Exercise 4 Determining the ideal amount of Bentonite required to stabilize a wine against Protein Cloud. Evaluation of various Bentonite formulations.
  5. Exercise 5 Enzymatic determination of Malic acid.
  6. Exercise 6 Determination of Malic acid by the paper chromatography method.
  7. Exercise 7th Metallic opacities (Fe+++ & Cu+).
  8. Exercise 8 Deironing.
  9. Exercise 9th Gelatin Index
  10. Exercise 10th BSA Index.
  11. Exercise 11 Evaluation of various processing materials in terms of their ability to affect the tannic character of wines.
  12. Exercise 12 Targary Stabilization. (Refrigerator Test, Conductivity Test).
  13. Exercise 13th Wine Filterability Control.
  14. Exercise 14 Evaluation of various wine packaging materials.
    Cork / bottle system assembly study.
    • Absorption of glass in UV radiation.
  15. Exercise 15 Demonstration of mechanical equipment – ​​Visit to wineries.

 

RECOMMENDED BIBLIOGRAPHY

  1. Pascal Ribéreau-Gayon, Yves Glories, Alain Maujean, Denis Dubourdieu. “Treatise on Oenology – (Vol.2)”. Dunod, Paris 1998. ISBN: 2 10 003948 2.
  2. Jean Ribéreau-Gayon, Emile Peynaud, Pascal Ribéreau-Gayon, P.Sudraud. “Treatise on Oenology – Wine sciences and techniques – (Vol.4)”. Dunod, Paris 1977. ISBN: 2 04 005182 1.
  3. Ron S. Jackson. “Wine science. Principles and applications”. Academic Press, Inc. California, 1994. ISBN : 0 12 379060 3.
  4. Emile Peynaud. “Knowledge and work of wine”. Dunod, Paris 1981. ISBN: 2 04 011417 3.
  5. Lallemand Scientific Interviews. “The microbiology of sparkling wines V 3”. Lallemand © Toulouse 1994.
  6. Lallemand Scientific Interviews. “Fermentation Technology V2”. Lallemand © Toulouse1994.
  7. Hans R. Luthi and Ulrich Vetsch. “Microscopic Analysis and Appreciation of wines and fruit juices in practice”, Avenir Œnology Collection.
  8. Roger B.Boulton et al. “Principles and practices of winemaking”, Aspen Publishers Inc., New York, c1996, ISBN : 08342 127 06.
  9. Bruce W. Zoecklein et al. “Wine analysis and Production”, Chapman & Hall, New York, c 1995, ASIN :041 298 2412.
  10. Kenneth C. Fugelsang. “Wine Microbiology”, Aspen Publishers Inc., New York, c1997, ISBN : 04120661 14
  11. Cornelius S. Ough. “Winemaking basics”, Haworth Press, New York, 1991, ISBN : 15602 200 58.
  12. Richard P. Vine et al. “Winemaking : From grape growing to marketplace”, Chapman & Hall, New York, c 1997, ISBN : 083421699x.
  13. David R. Storm. “Winery utilities : planning, design and operation”, Aspen Publishers Inc., New York,c1997, ISBN : 08342 198 16.
  14. Gerhard Troost. “Technology of wine”. Ulmer, Stuttgart 1988. ISBN: 3 8001 5816 7
  15. André Brugirard. “Practical Aspects of Fining Musts and Wines”. Oenoplurimedia sarl, Chaintré 1997, ISBN: 2 905 428 11 2.
  16. Bernard Gautier. “Practical Aspects of Wine Filtration”. Oenoplurimedia s.a.r.l., Chaintré. CollectionAvenir Œnologie.
  17. Joel Rochard. “Practical Aspects of Thermal Treatments of Wines”. Oenoplurimedia sarl,Chaintré. Avenir Oenology Collection.
  18. M.Riboulet. “Practical Aspects of Wine Corkage”. Oenoplurimedia s.a.r.l., Chaintré. CollectionAvenir Œnologie.
  19. Hans R. Luthi and Ulrich Vetsch. “Microscopic Analysis and Appreciation of wines and fruit juices in practice”, Avenir Œnology Collection.