Terroir 2016 banner
IVES 9 IVES Conference Series 9 The importance of soil and geology in tasting terroir; a case history from the Willamette valley, Oregon

The importance of soil and geology in tasting terroir; a case history from the Willamette valley, Oregon

Abstract

Wines differ from each other based on seven different factors: the type of grape; the bedrock geology and resulting soils; the climate; the soil hydrology; physiography of the site; the winemaker and the vineyard management techniques. The first five of these factors make up what the French call terroir, “the taste of the place”. All around the world the geology and soils make up an important component of the terroir of the wine. In the Willamette Valley of Oregon in the United States, the terroir is strongly influenced by the bedrock geology and soils. The three dominant groups are the volcanic soils, the Jory Series, that are developed on the Columbia River Basalts and the Willakenzie Series of soils developed on uplifted marine sedimentary rocks in the foothills of the Oregon Coast Range. The third group is developed on Laurelwood Soils in weathered loess with pisolites in it on weathered Columbia River Basalt. The wines developed out of grapes from the three different soils are very different. They are so different that the Willamette Valley AVA has been subdivided into six new AVA’s based on the differences in terroir, primarily the soils and geology.

DOI:

Publication date: June 23, 2020

Issue: Terroir 2016

Type: Article

Authors

Scott Burns

Department of Geology, Portland State University, Portland, Oregon, 97205 USA

Contact the author

Keywords

Pinot Noir, mineralogy, wine chemistry, soil chemistry, sensory analysis, Willamette Valley

Tags

IVES Conference Series | Terroir 2016

Citation

Related articles…

Influence of maturity on grape tyrosinase activity

Enzymatic browning of grape must remains a major issue in winemaking, especially when grapes are affected by grey rot.

EVIDENCE OF THE INTERACTION OF ULTRASOUND AND ASPERGILLOPEPSINS I ON UNSTABLE GRAPE PROTEINS

Most of the effects of ultrasound (US) result from the collapse of bubbles due to cavitation. The shockwave produced is associated with shear forces, along with high localised temperatures and pressures. However, the high-speed stream, radical species formation, and heat generated during sonication may also affect the stability of some enzymes and proteins, depending on their chemical structure. Recently, Ce-lotti et al. (2021) reported the effects of US on protein stability in wines. To investigate this further, the effect of temperature (40°C and 70°C; 60s), sonication (20 kHz and 100 % amplitude, for 20s and 60s, leading to the same temperatures as above, respectively), in combination with Aspergillopepsins I (AP-I) supplementation (100 μg/L), was studied on unstable protein concentration (TLPs and chitinases) using HPLC with an UV–Vis detector in a TLPs-supplemented model system and in an unstable white wine.

Alternative methods to evaluate the pinking susceptibility of white wines: derivative spectroscopy and ciel*a*b* colour analysis

Pinking describes the appearance of a salmon-red blush in white bottled wines produced exclusively from white grape varieties. It is understood as an undesirable chromatic phenomenon by both wine consumers and the industry. Nowadays, there are no treatments to fully reverse pinking once it occurs. Partial reversion has been shown after exposure of pinked wine to ultraviolet (UV) light.

OTA DEGRADATION BY BACTERIAL LACCASEST

Laccases from lactic acid bacteria (LAB) are described as multicopper oxidase enzymes with copper union sites. Among their applications, phenolic compounds’ oxidation and biogenic amines’ degradation, have been described. Besides, the role of LAB in the toxicity reduction of ochratoxin A (OTA) has been reported (Fuchs et al., 2008; Luz et al., 2018). Fungal laccases, but not bacterial laccases, have been screened for OTA and mycotoxins’ degradation (Loi et al., 2018). OTA is a mycotoxin produced by some fungal species, such as Penicillium and Aspergillus sp., which infect grape bunches used for winemaking.

Changes in phenolic maturity and texture characteristics of the grape berry under pre-, and post-veraison water deficit

Kékfrankos (Vitis vinifera L.) grapevines grafted on Teleki-Kober 5BB rootstock were submitted to water deficit under greenhouse conditions.