Enology 1

A.Y. 2024/2025
10
Max ECTS
96
Overall hours
SSD
AGR/15
Language
Italian
Learning objectives
The teaching is aimed to provide an in-deep knowledge of the scientific principles underlying the wine production and based on the biological, physical and chemical needed to their comprehension. More specifically, Oenology 1 is aimed to provide the knowledge to successfully effect the transformation of grape into wine in a winery. The lectures will provide the formation needed to know and manage the machines used in the winemaking chain as well as the physical, biological and chemical phenomena involved with it, in order to understand the role of each process step and its effect on the product characteristics. The training activities applied for solving problems related mass balance, energy balance and kinetics, will reinforce the specific calculation ability. Moreover, the teaching will provide fundamentals to understand the special production techniques needed to obtain wine with peculiar sensory properties and described in the next teaching course Oenology 2.
Expected learning outcomes
In the end of the course the student shall know the composition of ripe and ripening grape, as well as the role of each grape constituent on the final properties of wine. Moreover, the student shall know the effects of the grape harvest, transport and wine making on the constituents of grape, must and wine as well as on the sensory properties. Students shall be able to lead the alcoholic fermentation and the variables affecting it. Moreover, he/she shall know and size the machines used in the winery a well as to understand their working principle and the effect on the final product. The student shall acquire suitable technical language properties.
The student will be able to size the wine making machines and their mass and energy balances. The student shall be able to describe the sensory properties of wine, to qualitatively assess them, and to use those data to tune the production process. The student shall be able to participate consistently to the wine making, as well as to make choices in agreement with the expected result. Finally, the student shall be able to attend the compulsory factory internship provided in the end of the course as fully aware of the assigned activities, correctly performing them as well as adopting a critical and rational approach. The student shall be able to write down a technical report concerning the activities carried out during the in-winery internship suitable to the final degree report.
Single course

This course can be attended as a single course.

Course syllabus and organization

Single session

Lesson period
year
Course syllabus
Lectures content of the first unit (Unit Operations)
- Definition of the wine production chain.
- Quantities. Unit of measurement, dimensions, dimensional analysis. Exercises.
- Mass balances: theory and exercises.
- Energy balances: theory and exercises.
- Heat transport by conduction and convection. Energy balances in heating and cooling operations. Steam table. Heat exchangers. Exercises.
- Evaporation. Types of evaporators. Mass and energy balances in evaporation. Heat economy and optimization. Exercises.
- Fluid mechanic. Hydrostatic pressure. Exercises.
- Fluid dynamic. Laminar flow and turbulent flow. Bernoulli equation and load losses. Fluid transport. Exercises.
- Settling: theory and equipment. Exercises.
- Centrifugation: theory and equipment. Exercises.
- Filtration: theory and equipment. Exercises.
- Distillation: theory and equipment. Examples of spirits.

Lectures content of the second unit (Principles anf fundamentals of wine making).
- Overview of red wine making process. Structure and composition of grape bunch and berry. Properties and oenological role of monosaccharides, organic acids, salts an anthocyanin.
- Grape flavanols and proanthocyanidines: distribution in grape, chemical structure, composition, size and properties. Meaning of tannin. Polysaccharides and cell wall structure. Interaction between tannin and polysaccharides.
- Evolution of sugars and acids over the ripening. Correlation between acidity and acid taste.
- Grape ripening and its effect on wine properties: evolution of cations, cell wall polysaccharides, native pectolytic enzymes, anthocyanin and proanthocyanidins from skin and seed.
- The concepts of ripeness (technological, phenolic and cellular). Methods for assessing the phenolic ripeness: spectrophotometric methods, colour indices, quantification of flavonoids.
- Comparison between handmade and mechanical harvest. Effect of the harvest on the grape properties. Role of the grape carrying system on the microbiological properties of grape must. Role and use of sulphite on the control of microorganisms.
- The cold and air-free transport of harvested grape. Sorting and rinsing grape systems. Role of destemming and machinery for achieving it. Grape crushing. Polyphenol oxidase enzymes: activity, distribution in the berry, substrate affinity, inhibition. Straight and indirect phenol oxidation and the role of sulphite.
- Ascorbate and glutathione as anti-oxidants. The managing of sulphite addition in grape must. Chaptalization: sucrose, concentrated musts and their production. Vacuum concentration. Reverse osmosis and spiral wound filters. Spray-dryer and RCM. Correction of grape must acidity: purposes and methods of pH and acidity correction. Use of acids and basic salts according to the law indications. The management of sulphite in grape must.
- The management of the alcoholic fermentation: role of yeast other than ethanol production, effect of temperature on Saccharomyces and autochthonous microflora, role of microbial count on the prevalence of Saccharomyces.
- Products of alcoholic fermentation: the CO2 and the health risk for the employees over the vinification. Fermentative self-heating and its effect on the cell membranes. The activity of ethanol an temperature: unsaturated membrane lipids and the role of sterols. The role of oxygen on the production of unsaturated lipids. Qualitative and quantitative aspects of grape must oxygenation.
- Yeast available nitrogen and its role on cell growth. Kinetics of nitrogen consumption and the related nutritional integration.
- The management of fermentation yeast inoculation and stuck fermentation.
- Overview of white wine making. The sensory properties of white wine. The management of harvest of for white wine making. Principles of grape pressing. Pneumatic membrane presses, vertical presses, the Coquard press pressing. The continuous presses: Archimedean's screw press, Branco press.
- Grape must clarification and its effect on the sensory properties of wine. Measuring system of must turbidity. The Stokes' law and the physical principles of the clarification methods. The role of hexogen pectolytic enzymes. Settling and floatation techniques. Lees filtration on vacuum drum filter.
- Cold skin maceration for white wine making. Calulation of heat balance for dry ice usage. Effect of cold skin maceration on terpene extraction.
- Physical-chemical phenomena involved with fermentative maceration. Co-polymerization phenomena of anthocyanin and proanthocyanidins: oxidative origin of ethanal. Fundamentals of phenolic evolution in red wine.
- Overview of the oxidative ageing of wine and the role of the anthocyanin to proanthocyanidins ratio. Kinetics of phenol extraction over the fermentative maceration. Role of maceration on the phenolic evolution of red wine.
- Extraction behaviour of grape skin and seed. Role of solid material, temperature, ethanol and mechanical force on maceration and phenol ectraction. Comparison between pumping-up and punching-down. Heat dissipation.
Prerequisites for admission
The knowledge provided by the lectures needs a suitable background about a number of subjects of physics, yeast metabolism and wine chemistry. Therefore, the student must have passed the exams related to Physics and Wine Chemistry.
Teaching methods
The teaching methods consist of:
- Lectures: aimed to teach the theoretical knowledge to both understand and apply the winemaking practices shown during the course.
- Calculation exercises: aimed at getting confident in solving quantitative problems usually occurring along with the winemaking processes.
- Training sessions of technical wine tasting: aimed to achieve sensitivity and skills in evaluating visual, tasting, and olfactory properties of wine useful to assess wine under production.
- Educational visits at companies producing facilities and products for winemaking: they will allow students to deepen the technical topics of equipment and/or of enology products usually used in winemaking.
Teaching Resources
- PowerPoint slides shown during the lectures and available on the myAriel web portals along with the bibliographic references therein reported.
- Carlo Pompei. Operazioni unitarie della tecnologia alimentare. (2009) Casa Editrice Ambrosiana.
- David E. Block, Konrad V. Miller. Unit operations in winery, brewery, and distillery design. https://doi.org/10.1201/9781003097495.
- Handbook of Oenology vol. 1 and 2. Ribereau Gayon et al. (2018). Ed. Edagricole-New Business Media. Edizione 4.
Assessment methods and Criteria
The examination is composed of two partial sections. The first one, concerning the unit operation, is written and made up of: i) a calculation trial dealing with the specific operations tackled during the course, ii) a description of the industrial processes learned, and iii) a schematic drawing of winery machines with the explanation of their working principle. The use of the pocket calculator is allowed during the 90-minute trial. The examination grade, as thirties, will be reported in the electronic bulletin board of myAriel web portal.
The second partial section, concerning the fundamentals of enology, is made up of 30-minute written calculations dealing with simple procedures possibly occurring in winery. In case of a positive result, it's readily followed by an oral trial starting with a careful description of one of the winery equipment. The following parameters will be considered as evaluation tools: contextualization and connection ability of enology knowledge learned in the course, correctness of answers, technical language abilities, and summarizing ability. The grade from this partial section, as thirties, is orally communicated at the end of the trial and can be increased up to 2/30 based on the result achieved with the test performed at the end of the exercise activities.
At the end of the technical wine-tasting activities, the students attending 2/3 of the exercise activities will be allowed to apply a 30-minute closed-ended test with ten questions to assess their knowledge.
The final overall grade, as thirties, is the weighted average of the results achieved with the partial scores.
Students with specific learning disabilities or other disabilities are requested to contact the teacher via email at least 15 days before the exam session to agree on any personal compensatory measure. In the email addressed to the teacher, the respective University services must be reported in CC: [email protected] (for students with LD) and [email protected] (for students with other disabilities).
AGR/15 - FOOD SCIENCE AND TECHNOLOGY - University credits: 10
Practicals: 32 hours
Lessons: 64 hours
Shifts:
Professor(s)
Reception:
By schedule
Office (Building 21040 - entrance on side Room 4 - I floor)