THE HOME WINEMAKERS MANUAL Lum Eisenman PREFACE Most home winemaking books are written like cookbooks. They contain winemaking recipes and step by step directions, but little technical information is included. The goal of these books is to provide enough information so the reader can make a successful batch of wine. Enology textbooks are the other extreme. They are very technical and can be difficult to comprehend without a background in chemistry and microbiology. These books are intended to give professional winemakers the specialized backgrounds needed to solve the wide variety of problems encountered in commercial wine production. This book is an attempt to provide beginning home winemakers with basic “how to” instructions as well as providing an introduction to some of the more technical aspects of winemaking. However, the technical material has been concentrated in a few chapters, so readers can easily ignore much of the technical content until an interest develops. If you have a quantity of fresh grapes to convert into wine, read Chapter 1 and the first few pages of Appendix A. This material will give you enough information to start successful grape wine fermentation. Appendix A is written in a quasi outline form, and it provides a brief description of the entire winemaking process. If you have some fresh fruit and wish to make wine before the fruit spoils, read Chapter 21. This is a “stand alone” chapter, and successful fruit wines can be made from the information provided here. The first few pages provide enough information to prepare the fruit and start fermentation. The rest of the chapter can then be read at your leisure. Chapters 1, 2, 3, 4, 7, 8, 9, 10, 12, 14, 15 and 17 provide general information on home winemaking. These chapters discuss materials, facilities, equipment and basic processes. Much of this material is basic and should be of interest to most readers. The material presented in Chapters 5, 6, 11, 13 and 16 is a bit more advanced. These five chapters focus mostly on “what” and “why” rather than on “how.” Beginning winemakers may wish to skip these chapters until they become more experienced. Chapters 18 and 19 are case studies of making a red and white wine. These two chapters provide a detailed chronology of the production of two typical wines. Chapter 20 describes hot to make small quantities of sparkling wine, and Chapter 22, contains practical “how to” information of general interest. Chapter 23 describes six common laboratory wine tests. The significance of the tests, materials, apparatus and procedures are discussed. I hope you enjoy my little book on home winemaking. Lum Eisenman Del Mar, 1998 TABLE OF CONTENTS Chapter 1. The Winemaking Process 1 Chapter 2. Home Winemaking Costs 6 Chapter 3. Equipment and Facilities 8 Chapter 4. Winery Materials 16 Chapter 5. Sugars and Acids 22 Chapter 6. pH and Sulfur Dioxide 29 Chapter 7. Winery Sanitation 36 Chapter 8. Crush Season 42 Chapter 9. Harvest 47 Chapter 10. Grape Processing 52 Chapter 11. Wine Yeast 59 Chapter 12. Primary Fermentation 63 Chapter 13. Malolactic and Other Fermentations 73 Chapter 14. Fining and Fining Materials 79 Chapter 15. Clarification and Stabilization 86 Chapter 16. Wine Filtration 94 Chapter 17. Bottling 98 Chapter 18. Red Wine: A Case History 104 Chapter 19. White Wine: A Case History 109 Chapter 20. Making Sparkling Wine 114 Chapter 21. Making Fruit Wine 119 Chapter 22. Hints, Kinks and Gadgets 133 Chapter 23. Laboratory Wine Testing 143 Appendix A Step by Step Winemaking 152 Appendix B Conversion Factors 159 Appendix C Bibliography 161 Appendix D Sources 163 Appendix E Selected Wine Terms 164 ACKNOWLEDGMENTS Many people contributed to this book, and I greatly appreciate all their help. In particular, I wish to thank the following people who expended much time and effort on my behalf. Thanks to Dr. Roger Seapy for critiquing the manuscript for technical content and for providing many corrections and beneficial suggestions. Thanks to Lynn Alley and Terry Whyte for reading the original manuscript and suggesting many useful changes in content, style and organization. Thank you Dr. James Jenkins for many helpful technical discussions and suggestions for improving the manuscript. Thanks to Jim Graver for reviewing the chapter on fruit winemaking and providing many helpful suggestions. Thank you Duane deBoer for reading the manuscript and making many technical suggestions from the perspective of a professional winemaker. Special thanks Barbara Scherman for the many hours she spent attempting to untangle my inept prose. Chapter 1 THE WINEMAKING PROCESS Winemaking can be divided into four basic phases. The first phase consists of finding a source of high quality fruit and making sure the grapes are harvested in an optimum condition. Buying small quantities of high quality fruit is not easy, and this is the most difficult winemaking phase for home winemakers. The second phase consists of fermenting the grapes into wine. Winemakers manage the fermentation by controlling several different fermentation parameters such as temperature, skin contact time, pressing technique, etc. During the third phase, the new wine is clarified and stabilized. Winemakers clarify wine by fining, racking and filtration. Removing excessive protein and potassium bitartrate stabilizes wine. These materials must be removed to prevent them from precipitating out of the wine later. In the fourth phase of winemaking, the winemaker ages the wine. Most high quality wines are aged in bulk and then for an additional time in the bottle. Winemakers have an active role throughout the lengthy bulk aging process. Wines are smelled, tasted and measured every few weeks, and any needed adjustments are made promptly. Except for the first phase, the other three winemaking phases overlap each other. New wine starts to clarify toward the end of the fermentation period. Some tartrates precipitate out during primary fermentation, and the wine becomes more stable. Of course, wine is aging throughout the winemaking process. Each phase makes a specific contribution to wine characteristics, but the first phase has the greatest influence on wine quality. RED WINES AND WHITE WINES High quality, red wine grapes have colorless juice. All of the red color is in the grape skins, and winemakers must leave the juice in contact with the skins for a considerable time to extract the color. Red wine is made by crushing the grapes and then fermenting the juice, the pulp, the skins and the seeds together for several days. Near the end of sugar fermentation, a winepress is used to separate the liquid from the solid materials. White wine is made by a differently than red wine. First the grapes are crushed and pressed immediately to separate the juice from the solids. After pressing, the skins, stems and seeds are discarded, and the juice is cooled to a low temperature. Then the cold juice is allowed to settle for several hours, and the clear juice is decanted off the residue before it is fermented. White wines are made by fermenting clarified juice. These are the fundamental differences between making quality, red wine and white wine. At first glance, the two winemaking processes may appear similar because several steps are identical. Nevertheless, the steps are done in a different sequence, and the sequence makes a large change in wine characteristics. The two processes are shown in Figure 1. 1 IN THE VINEYARD It has often been said that wine quality is made in the RED WINE PROCESS vineyard, and few experienced winemakers disagree with this statement. The soil, climate, the viticulture and all other aspects of Crush > Ferment > the vineyard environment contribute to the quality of the wine. Even Press > Clarify > if the winemaker does a perfect job, the quality of the starting grapes Stabilize > Age > always determines the potential quality of the wine. Grape quality is Bottle extremely important. Many winemakers feel that when a grape growing problem develops, the difficulty must be recognized and WHITE WINE PROCESS promptly resolved to assure fruit quality. Consequently, professional and amateur winemakers prefer to grow their own grapes. Then Crush > Press > they have complete control over the vineyards. Settle > Ferment > Clarify > Stabilize > Age > Bottle FERMENTATION Two different fermentations occur in most red wines, and Figure 1. The red and these same fermentations are often encouraged in heavier styled white winemaking white wines like Chardonnay or Sauvignon Blanc. In addition, a processes. variety of yeast and bacteria can grow in wine, and many of these microorganisms can cause other fermentations. Primary Fermentation Conversion of the two major grape sugars (glucose and fructose) into ethyl alcohol is called primary fermentation. Yeast in the wine produce enzymes, and the enzymes convert the sugars into alcohol. Converting grape sugars into alcohol is not a simple process. Many steps are involved in this transformation, and the yeast must produce several different enzymes. Malolactic Fermentation Malic acid in the grapes is converted into lactic acid during the secondary fermentation. The necessary enzymes are produced by bacteria rather than by yeast. Several different types of bacteria can produce malolactic (ML) fermentation, and these bacteria are called lactic bacteria. Lactic acid is weaker than malic acid, so malolactic fermentation reduces the overall acidity of the wine. In addition, some byproducts produced during the ML fermentation can make a positive contribution to the complexity of the wine. Other Fermentations Depending upon the winemaking conditions, several other fermentations can and often do occur in wine. Some bacteria can ferment the glycerol in the wine into lactic and acetic acids. Other types of bacteria can transform the natural grape sugars into lactic and acetic acid. A few species of bacteria can ferment the tartaric acid in the wine into lactic acid, acetic acid and carbon dioxide gas.