Terroir 2016 banner
IVES 9 IVES Conference Series 9 Tasting soils in Pinot noir wines of the Willamette valley, Oregon

Tasting soils in Pinot noir wines of the Willamette valley, Oregon

Abstract

The conventional wisdom of vintners is that alkalinity, and thus less sour and more rounded taste, are enhanced in wine and grapes challenged by low-nutrient soils. A common thread here is pH, an objectively measurable variable that is both a part of wine taste and a proxy for soil fertility. The role of low-pH soils is supported by metadata on Oregon wines from different soils in the Willamette Valley of Oregon, USA, which show significant inverse correlations between minimum pH of the soil and pH of finished Pinot Noir wine. There is also a direct correlation between depth of clayey horizons and pH of the finished wine.

The minimum pH of these soils is near the base of the clayey (Bw or Bt) horizon and is inversely correlated with depth of the clayey horizon. Low soil pH is found in thick middle Pleistocene soils of bedrock (Jory, Willakenzie, Laurelwood, and Bellpine soil series) and high soil pH in thin soils on late Pleistocene and Holocene Missoula Flood deposits and loess (Hazelair, Woodburn, and Chehulpum soil series). Similar relationships are found between soil pH or depth and the pH of grapes at harvest, which is lower and more varied than pH in finished wine. These relationships are especially notable in years of good harvest, but obscured by wine- making techniques in years of poor harvest. Good harvest years are not necessarily vintages esteemed by wine connoisseurs, which are more strongly correlated with low October precipitation.

DOI:

Publication date: June 23, 2020

Issue: Terroir 2016

Type: Article

Authors

Gregory J. Retallak (1) and Scott F. Burns (2)

(1) Dept. of Geological Sciences, University of Oregon, Eugene, Oregon 97403, USA
(2) Dept. of Geology, Portland State University, Portland, Oregon 97207, USA

Contact the author

Keywords

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

Tags

IVES Conference Series | Terroir 2016

Citation

Related articles…

Influence of the vintage, clone and rootstock on the chemical characteristics of Syrah tropical wines from Brazil

In the Northeast of Brazil, vines can produce twice a year, because annual average temperature is 26ºC, with high solar radiation and water availability for irrigation.

Rapid damage assessment and grapevine recovery after fire

There is increasing scientific consensus that climate changeis the underlying cause of the prolonged dry and hot conditions that have increased the risk of extreme fire weather in many countries around the world. In December 2019, a bushfire event occurred in the Adelaide Hills, South Australia where 25,000 hectares were burnt and in vineyards and surrounding areas various degrees of scorching and infrastructure damage occurred. The ability to coordinate and plan recovery after a fire event relies on robust and timely data. The current practice for measuring the scale and distribution of fire damage is to walk or drive the vineyard and score individual vines based on visual observation. The process is time consuming, subjective, or semi-quantitative at best. After the December 2019 fires, it took many months to access properties and estimate the area of vineyard damaged. This study compares the rapid assessment and mapping of fire damage using high-resolution satellite imagery with more traditional ground based measures. Satellite imagery tracking vineyard recovery in the season following the bushfire is being correlated to field assessments of vineyard productivity such as canopy health and development, fertility and carbohydrate storage. Canopy health in the seasons following the fires correlated to the severity of the initial fire damage. Severely damaged vines had reduced canopy growth, were infertile or had very low fertility as well as lower carbohydrate levels in buds and canes during dormancy, which reduced productivity in the seasons following the bushfire event. In contrast, vines that received minor damage were able to recover within 1-2 years. Tools that rapidly and affordably capture the extent and severity of damage over large vineyard area will allow producers, government and industry bodies to manage decisions in relation to fire recovery planning, coordination and delivery, improving the efficiency and effectiveness of their response.

The effect of wine matrix on the initial release of volatile compounds and their evolution in the headspace

There is evidence in the literature that non-volatile wine matrix can modify the release and therefore the perception of the compounds involved in wine aroma [1-3].

Elementi in traccia e ultratraccia nell’uva: possibili applicazioni ai fini della tracciabilità geografica

Nel presente studio si è ricercata la possibilità di associare l’uva al territorio mediante parametri chimici indipendenti da variabili climatiche ed antropiche.

Wine odors: chemicals, physicochemical and perceptive processes involved in their perception

The odors of wines are diverse, complex and dynamic and much research has been devoted to the understanding of their chemical bases. However, while the “basic” chemical part of the problem, namely the identity of the chemicals responsible for the different odor nuances, was satisfactorily solved years ago, there are some relevant questions precluding a clear understanding. These questions are related to the physicochemical interactions determining the effective volatilities of the odorants and, particularly, to the perceptual interactions between different odor molecules affecting in different ways to the final sensory outputs.