Terroir 2016 banner
IVES 9 IVES Conference Series 9 Pinot blanc: how terroir and pressing techniques impact on the must composition and wine quality

Pinot blanc: how terroir and pressing techniques impact on the must composition and wine quality

Abstract

This study investigates how different pressing techniques impact on the sensory profile of Pinot Blanc wines sourced from different terroirs.
Two vineyards, both on east slopes, one at 550 meters elevation with a high quality potential and one at 250 meters with a medium quality potential were compared. Vineyards were chosen in collaboration with the head-winemaker of the cooperative Tramin based on his observations and experience about quality potential. For the experiment 600 kg of grapes from each vineyard site were hand-picked the day before harvest for the commercial winery took place.

Grapes were stored over night at 4°C and processed in the experimental winery at Laimburg research centre the day after harvest. Three different pressing techniques were applied in duplicates of 100kg each. Treatments were composed as follows: (1) “classic”, pre-installed press program with 120 minutes and crumbling after each pressure step, (2) “cremant”, gentle and sequential press program with 180 minutes and fewer crumbling steps and (3) “maceration” consisted of a 120 minutes cold soak followed by a very quick press program of 30 minutes.

To track the evolution and extraction kinetics of pH, total acidity, tartaric acid, malic acid, total polyphenols and catechins, juice samples were taken after each cycle and analyzed right away in the wine laboratory.
At approximately 150 kPa (21,8 psi) pressure the must is divided in fraction one and fraction two what corresponds to the press-wine. Two experimental wines are made out of each batch of grapes: one contains only must from the first fraction, and the other is a combination of fraction one and two in the original proportion.

Chemical must composition depends on the vineyard site and the processing technique in the winery. Total acidity, pH, malic acid and polyphenol content of the must are affected from the chosen press program. Nonetheless the absolute content of the chemical components is different, for grapes coming from different vineyards and the different pressing techniques, the trend of the extraction of these must components remains more or less the same during the pressing procedure.

Sensory analyses and aroma analyses show a distinct profile of the two vineyard sites. The different pressing techniques had an impact on the sensory profile of the wines. To what has been observed in this experiment, for overall wine quality it was beneficial to use the entire must; wines made without the press-fraction are described as too light, not as complex and not as typical.
Important differences are observed for the two vintages shown in this work. Depending on the quality potential of the grapes and the vintage, a two hours maceration followed by a quick pressing showed interesting results. This might be a promising option to save press-capacity and to process more fruit in the short period of harvest.

DOI:

Publication date: June 24, 2020

Issue: Terroir 2016

Type: Article

Authors

Konrad Pixner

Research Centre for Agriculture and Forestry Laimburg, Bolzano, Italy

Contact the author

Keywords

Terroir, viticulture, Pinot Blanc, sensory analysis, wine quality

Tags

IVES Conference Series | Terroir 2016

Citation

Related articles…

Physiological and growth reaction of Shiraz/101-14 Mgt to row orientation and soil water status

Advanced knowledge on grapevine row orientation is required to improve establishment, management and outcomes of vineyards on terroirs with different environmental conditions (climate, soil, topography) and in view of a future change to more extreme climatic conditions. The purpose of this study was to determine the combined effect of row orientation, plant water status and ripeness level on the physiological and viticultural reaction of Shiraz/101-14 Mgt.

Effects of mechanical leafing and deficit irrigation on Cabernet Sauvignon grown in warm climate of California

San Joaquin Valley accounts for 40% of wine grape acreage and produces 70% of wine grape in California. Fruit quality is one of most important factors which impact the economical sustainability of farming wine grapes in this region. Due to the recent drought and expected labor cost increase, the wine industry is thrilled to understand how to improve fruit quality while maintaining the yield with less water and labor input. The present study aims to study the interactive effects of mechanical leafing and deficit irrigation on yield and berry compositions of Cabernet Sauvignon grown in warm climate of California.

The effects of cane girdling on berry texture properties and the concentration of some aroma compounds in three table grape cultivars

The marketability of the table grapes is highly influenced by the consumer demand; therefore the market value of the table grapes is mainly characterized by its berry size, colour, taste and texture. Girdling could cause accumulation of several components in plants above the ringing of the phloem including clusters and resulting improved maturity. The aim of the experiments was to examine the effect of girdling on berry texture characteristics and aroma concentration.

Application of a fluorescence-based method to evaluate the ripening process and quality of Pinot Blanc grape

The chemical composition of grape berries at harvest is one of the most important factors that should be considered to produce high quality wines. Among the different chemical classes which characterize the grape juice, the polyphenolic compound, such as flavonoids, contribute to the final taste and color of wines. Recently, an innovative non-destructive method, based on chlorophyll fluorescence, was developed to estimate the phenolic maturity of red grape varieties through the evaluation of anthocyanins accumulated in the berry skin. To date, only few data are available about the application of this method on white grape varieties.

Different yield regulation strategies in semi-minimal-pruned hedge (SMPH) and impact on bunch architecture

Yields in the novel viticulture training system Semi-Minimal-Pruned Hedge (SMPH) are generally higher compared to the traditional Vertical Shoot Positioning (VSP). Excessive yields have a negative impact on the vine and wine quality, which can result in substantial losses in yield in subsequent vintages (alternate bearing) or penalties in fruit quality. Therefore yield regulation is essential. The bunch architecture in SMPH differs from VSP. Generally there is a higher amount but smaller bunches with lower single berry weights in SMPH compared to VSP.