Glutathione, a natural grape antioxidant, can protect the aroma and flavor of white and rosé wines and prevents premature aging.

White Wine Challenges

The increasing demand for white and rosé wines with fresh, fruity or floral characters has led to significant winemaking challenges.

• The aroma compounds in these lighter wines, such as Sauvignon Blanc, are fragile, and oxidation can quickly cause a loss of aroma and flavor. 
• Even wines like Riesling and barrel-aged Chardonnay have experienced premature or atypical aging as a result of oxidation. 
• Many winemakers are also under pressure to decrease the use of SO2 as an antioxidant while still maintaining protection from oxidation.

The Importance of Glutathione 

Glutathione, a natural tri-peptide found in grapes and wine, is a powerful antioxidant that protects white wines and rosés from oxidation and loss of aroma or flavor.

A low level of glutathione in grapes leads to lower levels in the juice, and early losses of aroma compounds. 

Glutathione levels fluctuate during production, as the compound can be absorbed by yeast and then released after fermentation. 

If final glutathione levels are low in young wines, they will experience faster loss of fresh varietal and fruity aromas, and poor aging potential. 

Monitoring Glutathione

Monitoring glutathione levels can be beneficial at all steps of the winemaking process to maximize white wine aroma and flavor, and prevent premature aging.

• The glutathione content in grapes indicates their antioxidant potential, and can be influenced by a number of factors including soil nitrogen, vineyard practices, and grape maturity levels. 
• Analyzing changes in glutathione levels during production helps to pinpoint where in the process glutathione is being lost – often from contact with air or exposure to copper residues. 
• A testing program can also identify winemaking processes that boost glutathione release after fermentation, and increase levels in wines.

Protect your wine’s aroma, flavor, and aging potential.
ETS Labs offers precise glutathione testing to help winemakers safeguard delicate white and rosé wines from oxidation. Whether you're fine-tuning vineyard practices or tracking changes through fermentation, our tools can guide you every step of the way.

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