Knowing and Making Wine by Emile Peynaud

One of the books that we have is this one written by Emile Peynaud, translated to English by Alan Spencer and published in 1984.
Emile Peynaud is considered to be the Father of Modern Enology and this book is well worth the read for a novice like me. Only now am I learning about the tremendous impact that Peynaud had in ushering in the modern age of winemaking. It was Peynaud in the 1950's who convinced winemakers in Bordeaux that they were harvesting grapes too early and their cellars were not a noble eyesore, but was in reality, unhygienic and detrimental to making quality wines.¹ Peynaud convinced winemakers to accept low acid levels in the grapes and wines and control temperatures in the cellars, especially during fermentation. These practices lead to richer, riper, and rounder wines which could be enjoyed when they were younger but which also had the ability to age.² The book is divided into 8 parts:

Part 1 Tasting and the Composition of Wine
Part 2 The Ripening of the Grape and Harvesting
Part 3 Microbiology of Wine and Fermentation
Part 4 Vinifications
Part 5 Storage and Aging
Part 6 Clarification of Wines
Part 7 Stabilizing Processes for Wines
Part 8 Bottling Wines

I am finding gems of knowledge sprinkled in every part of his book. Here is one for your consideration:
What is tourne?
Wine that has turned in French is described as having tourne, a sickness caused by the total fermentation of tartaric acid in wine into lactic acid, acetic acid and carbon dioxide. Certain lactic acid bacteria species are responsible for this unfortunate condition which results in a wine tasting flat and flabby. This is because of the increase in pH due to the decrease in tartaric acid. In red wine, the color becomes dull and brownish, the wine can go cloudy and develop silky waves when shaken in a glass. The carbon dioxide makes the wine gassy. As if this was not enough, advanced tourne has a disagreeable odor and a "mousy" flavor. There is a simple remedy. The bacteria that attack tartaric acid succumbs to sulfur dioxide additions. In 1984, Peynaud wrote, "...this disorder has become very rare in good vinifications and wines correctly stored. With the progress accomplished in this area, it may be confidently declared that tourne is on it's way to have disappeared altogether. However, it would be quite common if wines were made and kept without any sulfur dioxide being used at all."³
References:
1. Mike Steinberger, The Tastemaker, Slate, July 30, 2004.
2. Per-Henrik Mansson, Emile Peynaud, Who Influenced Winemaking Around the World, Dies at 92, Wine Spectator, July 21, 2004.
3. Emile Peynaud, "Knowing and Making Wine", 1984, John Wiley and Sons, pg. 259-260.