Introduction to Wine Laboratory Practices and Procedures

Transcription

1 Introduction to Wine Laboratory Practices and Procedures

2 Jean L. Jacobson Introduction to Wine Laboratory Practices and Procedures With 50 Figures, Including 2 Color Plates

3 Library of Congress Control Number: ISBN-10: e-isbn Printed on acid-free paper. ISBN-13: Springer Science+Business Media, Inc. All rights reserved. This work may not be translated or copied in whole or in part without the written permission of the publisher (Springer Science+Business Media, Inc., 233 Spring Street, New York, NY 10013, USA), except for brief excerpts in connection with reviews or scholarly analysis. Use in connection with any form of information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed is forbidden. The use in this publication of trade names, trademarks, service marks, and similar terms, even if they are not identified as such, is not to be taken as an expression of opinion as to whether or not they are subject to proprietary rights. The author has made every effort to ensure the accuracy of the information herein. However, appropriate information sources should be consulted, especially for new or unfamiliar procedures. It is the responsibility of every practitioner to evaluate the appropriateness of a particular opinion in the context of actual situations and with due considerations to new developments. Printed in the United States of America. (SPI/SBA) springer.com

4 To my sons, Christopher and Matthew, with profound love. To my twin sister, Joyce, my guardian angel and soul mate. To Kaarlo, for believing in me. To sisters Julie and Jeralyn, for their unconditional love. To Daddy, my hero. To Mother, who never gave up. To all of you who knew I could. ILYS v

5 Preface In the beginning, for me, winemaking was a romanticized notion of putting grape juice into a barrel and allowing time to perform its magic as you sat on the veranda watching the sunset on a Tuscan landscape. For some small wineries, this notion might still ring true, but for the majority of wineries commercially producing quality wines, the reality of winemaking is far more complex. The persistent evolution of the wine industry demands continual advancements in technology and education to sustain and promote quality winemaking. The sciences of viticulture, enology, and wine chemistry are becoming more intricate and sophisticated each year. Wine laboratories have become an integral part of the winemaking process, necessitating a knowledgeable staff possessing a multitude of skills. Science incorporates the tools that new-age winemakers are utilizing to produce some of the best wines ever made in this multibillion dollar trade. A novice to enology and wine chemistry can find these subjects daunting and intimidating. Whether you are a home winemaker, a new winemaker, an enology student, or a beginning-to-intermediate laboratory technician, putting all the pieces together can take time. As a winemaker friend once told me, winemaking is a moving target. Introduction to Wine Laboratory Practices and Procedures was written for the multitude of people entering the wine industry and those that wish to learn about wine chemistry and enology. It is a guide to understanding basic enology, wine chemistry, safety, quality control, wine history, winemaking processes, bottling, and analytical procedures. Areas of study are applicable to the majority of wine laboratories in the world. The reader will gain a firm basic working knowledge of the wine laboratory and enology upon which to build a greater understanding of more advanced theory and technical information. Make wine with honor. Healdsburg, California Jean L. Jacobson vii

6 Acknowledgments With great appreciation, I would like to thank the people who laboriously read chapters and supplied feedback: Marcia Manix, Sharon Dougherty, Cathy Jacobson, Dr. Les Nouget, Joyce Nouget, Dr. Will Brogdon, Christine Brogdon, Jeralyn Heath, Joanne Foote-Lynch, and Galen McCorkle. Thank you to Kendall-Jackson Wine Estates for your cooperation in this project. I would also like to thank the manufacturers, governmental agencies, and wineries that provided photographs and information used in this book. ix

7 Contents Preface vii Color Insert facing page 46 1 Chemistry to Remember Introduction Metric System Density and Specific Gravity Liquids, Solids, and Gases Pressure and Temperature Liquids Gases Chemistry Fundamentals Matter Structure Periodic Table Compounds Solutions Electrolyte Solutions ph Oxidation: Reduction and Electrolysis Halogens Sulfur Organic Chemistry Safety First Introduction Regulatory Agencies and Acts Laboratory and Winery Hazards Chemical Hazards Toxic Chemicals Dose, Duration, Frequency, and Routes of Exposure Classification of Toxins Reactive Chemical Hazards Chemical Handling and Storage Ordering and Receiving Proper Labeling Proper Storage Chemical Waste Classification Waste Disposal Personal Protection Equipment Chemical Accidents and Emergencies xi

8 xii Contents Spills Accidental Inhalation or Ingestion Fire Gas Cylinder Leaks Physical Hazards Physical Hazards Associated with Laboratory Work Equipment Hazards Compressed and Liquid Gas Hazards Vacuum Hazards Glassware Hazards Slip, Trip, and Fall Hazards Ergonomic Hazards Physical Hazards in the Cellar Damage Control What s Your Number? Introduction Quality Setting up a QA Program Laboratory Staff Analytical Methods Method Validation Reagents, Standards, and Controls Analytical Techniques Calculations Proper Measurement Sample Quality Preventative Maintenance Records Inadvertent Error Berry to Bottle Introduction Wine History Grape Varieties Appellations France Burgundy Bordeaux Rhône Loire Champagne Languedoc-Roussillon Provence Italy Piedmont Tuscany Emilia Romagna-Veneto Spain Rioja-Penedés-Cava Jerez Portugal Douro Vinhos Verdes

9 Contents xiii Madeira Germany South Africa Chile Argentina Australia New Zealand United States New York Washington Oregon California Wine Production Overview Vineyard Harvest Fermentation Maturation Blending, Fining, and Stabilization Filtration and Bottling Sparkling Wine Money Matters Vineyard to Harvest Introduction The Grape Mature Grape Physiology Organic Acids Alkaline Metals Nitrogen Compounds Phenolic Compounds Aromatic Substances Sugar Grape Structure Seeds Skin Pulp Preharvest Vineyard Sampling Sugar Determinations Oechslé Baumé Balling and Brix Glucose and Fructose Determinations Enzymatic Method Other Residual Reducing Sugar Methods Potential Alcohol (Ethanol) Determinations Alcohol (Ethanol) Determinations Ebulliometry Method Other Alcohol Determination Methods ph and Acidity Determinations ph Titratable Acidity Potassium, Calcium, and Other Alkaline Metals Determinations Total Phenols and Anthocyanin Determinations

10 xiv Contents 5.4 Harvest Nitrogen and Amino Acid Determinations Insoluble Solids Determinations Total, Free, and Bound Sulfur Dioxide Determinations Forms of Sulfur Dioxide Maintaining SO 2 Levels Aeration Oxidation Method Ripper Method Other Methods Summary Fermentation Introduction Preparation for Fermentation Sugar Adjustments Acid Adjustments Acid Additions Deacidification Baseline Analyses Volatile Acidity and Acetic Acid Determinations Acetic Acid Enzymatic Method Volatile Acidity Distillation Method Primary Alcohol Fermentation Yeast Metabolism Cultured Yeast and Inoculation Monitoring Fermentation Soluble Solids (Apparent Brix) via Hydrometer Soluble Solids (Apparent Brix) via Density Meter Verification of Dryness Secondary Malolactic Fermentation Taxonomy and Morphology of Wine Microorganisms Lactic Acid Bacteria Yeasts Spoilage Bacterium Other Methods of Identification Prefermentation Analyses Oenococcus oeni Culture Preparation Culture Buildup Monitoring MLF L-Malic Acid Determinations Paper Chromatography Thin-Layer Chromatography Capillary Electrophoresis Enzymatic Method Cessation of Fermentation Maturation Matters Introduction Maturation and Aging Advantages of Maturation Removal of Substances Storage Containers Cooperage

11 Contents xv Wood Barrel Construction Protecting the Wine Oxidation Oxygen and Wine Color Formation of Acetaldehyde Microbial Spoilage Acetic Acid Bacterial Spoilage Lactic Acid Bacterial Spoilage Yeast Spoilage Conclusion Maintenance of Maturing Wines Barrel Storage Topping Racking Cellar Temperature Organoleptic Evaluation Organoleptic Terminology Wine Sensory Flavor Identification Fining Bentonite Fining Albumen Fining Gelatin and Isinglass Fining Copper Sulfate Fining Wine Stability Freeze Test Cold Conductivity Filtration Blending Fractional Blending Bottling Basics Introduction Packaging Labels Bottles Cork Cork Quality Control TCA Bottling Lines Preparing Wines for Bottling Required Analyses Sulfur Dioxide EtOH Acidity Microbial Growth Carbon Dioxide Oxygen and Wine Temperature Wine Density Prebottling Activities Bottling Line Sanitation Membrane Filter Integrity Test Bottling

12 xvi Contents Bottle Queue Membrane Filter Filler Corking Machine Quality Control Capsules, Wax, Labeling, and Storage Microbiological Monitoring Plating Media Plate Inoculation, Incubation, and Identification Required Analysis for International Trade Bottle Aging Analytical Procedures Introduction Procedures Spectrometric Color and Phenolic Measurement Density Measurement, Direct Method Specific Gravity Measurement Soluble Solids Measurement via Hydrometer Density, Specific Gravity, and Brix Measurements via Density Meter Soluble Solids Measurement via Refractometer ph Measurement Titratable Acids Assay, Manual Titratable Acids and ph Assay via Automated Titration Fluoride (F) Assay via ISE Ammonia (NH 3 ) Assay via ISE Free and Total Sulfur Dioxide (SO 2 ) Assay via Ripper Free and Total Sulfur Dioxide (SO 2 ) Assay via Aeration Oxidation Reducing Sugar and Residual Reducing Sugar (RS) Enzymatic Assay L-Malic Acid (LMA) Enzymatic Assay Acetic Acid (AC) Enzymatic Assay Volatile Acidity Assay via Distillation Insoluble Solids (% Solids) Measurement % v/v Alcohol Measurement via Ebulliometer Yeast and Bacteria Viability and Cell Counts Cold Stability Assay for the Verification of Bitartrate Stability via Freeze Test Cold Stability Assay for the Verification of Bitartrate Stability via Conductivity Heat Stability Assay for Verification of Protein Stability Carbon Dioxide (CO 2 ) Measurement via Carbodoseur Acidulation Trial Deacidulation Trial: Potassium Bicarbonate KHCO 3 (or K 2 CO 3 ) Gelatin Fining Trial Isinglass Fining Trial Egg White Fining Trial Bentonite Fining Trial Copper Sulfate (CuSO 4 ) Trial

13 Contents xvii 10 Reagents Introduction Reagents Acetaldehyde (C 2 H 4 O) 10% w/v Solution Acetic Acid (C 2 H 4 O 2 ) 1% w/v Standard Ammonia (NH 3 ) 0.1% w/v Standard Bentonite 5% w/v Slurry Brix Sucrose (C 12 H 22 O 11 ) Standard Copigmentation Buffer Copper Sulfate (CuSO 4 ) 100 mg/liter Solution Isinglass 0.5% w/v Solution Egg White 10% w/v Solution Ethanol (EtOH) Solutions and Standards Gelatin 1% w/v Solution Hydrochloric Acid (HCl) Solutions Hydrogen Peroxide (H 2 O 2 ) 0.3% v/v Solution Indicator Solution Iodine (I 2 ) 0.02N Solution L-Malic Acid (C 4 H 6 O 5 ) 0.2 g/l Standard Malic Acid (C 4 H 6 O 5 ) 10% w/v Solution Phosphoric Acid (H 3 PO 4 ) Solutions Potassium Bicarbonate (KHCO 3 ) 4.5 % w/v Solution Sodium Hydroxide (NaOH) Solutions Starch 1% w/v Solution Sulfur Dioxide (SO 2 ) 200 mg/l Solution Sulfuric Acid (H 2 SO 4 ) Solutions Tartaric Acid (C 4 H 6 O 6 ) 100 g/l Solution Thiosulfate (S 2 O 3 ) Solution Standardization Standardization of Acid Solutions Standardization of Base Solutions Standardization of 0.02N Iodine Solution Appendix Laboratory Chemical Safety Summaries 337 Bibliography 359 Index 365

14 Color Plate 1 FIGURE 2.2. NFPA Hazard Classification (NFPA, 2001). This warning system is intended to be interpreted and applied only by properly trained individuals to identify fire, health, and stability hazards of chemicals. The user is referred to the recommended classifications of certain chemicals in the NFPA Guide to Hazardous Materials, which should be used as a guideline only. Whether the chemicals are classified by NFPA or not, those using the 704 system to classify chemicals does so at their own risk. (Reprinted with permission from NFPA , System of Identification of Hazardous Materials for Emergency Response, Copyright 2001, National Fire Protection Association, Quincy, MA.).

15 Color Plate 2 FIGURE 8.2. Contaminated plating results from postbottled wine. Mold colonies are spreading, irregular in shape, off-white growths that appear fuzzy; yeast form small, smooth-surfaced, uniform colonies, milky in color; bacterial colonies are irregular in shape, smooth-surfaced, and are various colors.