Natural Vs Inoculated Fermentation

Natural Vs Inoculated Fermentation

Introduction Majority of white wines produced using

commercially available pure yeast strains. Natural fermentation occurs due to indigenous yeast population present in the winery

Inoculation Regulate and manipulate fermentation Strain chosen on basis of • • • • •

Physiological characteristics Alcohol yield Temperature tolerances Acetic acid formation Aroma characteristic

Consistent wines Decreased risk of spoilage

Natural Dependent upon wild yeast being present Less control Increased risk of spoilage Zero cost Different flavours and aromas

Winemaking Plan 12t chardonnay sourced from Tamar Ridge’s

White Hills Vineyard, Tasmania Wine 1 – 8CHWH71N - Natural • Pressed to a maximum of 500L/t • Straight to barrel

Wine 2 – 8CHWH71P- Inoculation • Pressed to a maximum of 200L/t • 80ppm SO2 and 20ml/1000L added • Cold settled, warmed and inoculated

Initial Analysis

Fermentation 8CHWH71N

8CHWH71P

Post Ferment Analysis

Post Ferment Battonage and topping 30ppm SO2 added prior to bottling

Tasting Wine 1 -

Natural

Wine 2 -

Inoculation

 Wines blended from 2006 barrels to minimise oak interference

Conclusion  Inoculation

 Control  Faster  Reduced risk of spoilage  Craft a wine to exact specifications

 Spontaneous

 Multiple strains of yeast present  Different aromas and flavours  Unknown factor  Different

References Lalland, 2006, Lallamand Wine Yeast Strains

http://www.lallemandwine.us/products/yeast_strains.php

 Gawel, Richard, Primary Fermentation of Wine,

http://www.aromadictionary.com/articles/winefermentation_article .html  Aspler, Tony, 2006,"What are the issues facing winemakers in choosing between natural fermentation and adding commercial yeast? Does it really make a difference in the final product?", http://www.tonyaspler.com/pub/articleview.asp?id=212&s=5  Rankine, Bryce, 2004, Making Good Wine, Pan Macmillan Australia, pp 106-111  Peynaud, Emile,1984, Knowing and Making Wine, A WileyInterscience publication, pp 93-119, pp 266-272  Tamar Ridge Estates, Kayena, Tasmania