Nagi

Degrees in viticulture and oenology from Hochschule Geisenheim University, Germany. Head winemaker at wineries in Germany. Viticulturist and oenologist. Now working independently as a winemaker and as a viticulture and winemaking consultant.

Consulting for wineries|Nagi wines

off-flavor

2025/7/14

Wine and Volatile Acidity: Origins and Impact of Acetic Acid in Wine

Many people who study wine have encountered the term “VA” at some point. Initially, the meaning of this abbreviation may not be immediately clear. VA stands for Volatile Acid, which translates to “volatile acidity” in Japanese. More precisely, volatile ac …

qualitycontrol

2025/7/12

Wine and Hygiene Management: Considering the Nature of Wine Character

Food should be hygienic. This seems like a given for those of us living in the modern era. However, Japan’s Food Sanitation Law was actually enacted in 1948, just 75 years ago. In 2018, this law was partially revised, making it mandatory for all food busi …

fermentation

2025/8/5

Fundamental Understanding of Non-Saccharomyces Yeasts: New Options in Modern Winemaking

In modern winemaking, yeast selection technology continues to evolve constantly. A recurring phenomenon is observed where specific yeasts gain attention due to outstanding performance in competitions or industry recommendations, leading to rapid expansion …

thorough-explanation

2025/7/29

The Complete Guide to Orange Wine Production

Overview In our previous article “Is Orange Wine Natural Wine?”, we explored the definition, origins, and relationship between orange wine and natural wine. This article provides a detailed examination of orange wine from a winemaking perspective. This ar …

qualitycontrol

2025/7/29

The Impact of Vibration from Three Perspectives | How Does Vibration Change Wine?

Once bottled and shipped from wineries, wines are influenced by various environmental factors that alter their taste. We describe these taste changes as aging or deterioration. When we think of wine aging or deterioration, oxidation and heat damage are li …

oenology

2025/7/6

Wine and pH – What Changes in pH Bring to Wine

One of the most critical factors in winemaking is pH. Many people may recall learning about pH in middle school science or high school chemistry classes. However, understanding how pH relates to wine can be challenging. When researching the relationship b …

oenology

2025/7/4

The Chemistry of Wine Ageing | Fundamentals of the Maillard Reaction

A chemical reaction known as the Maillard reaction exists. This reaction is also called the amino-carbonyl reaction. The browning of meat when grilled, the appetizing golden color of baked cookies or toast, and the appealing color of fish teriyaki glazed …

Brettanomyces bruxellensis

off-flavor wine

2025/7/3

Brettanomyces: The Yeast Behind Brett Off-Flavors in Wine

You open a bottle of wine you’ve been looking forward to and pour it into your glass. As you bring your nose close to enjoy the aromatic bouquet rising from the wine, something seems off. Many of you have probably had this experience. Wine that produces u …

off-flavor thorough-explanation

2025/7/3

A Comprehensive Guide to Petrol Notes in Wine

Are you familiar with the term “petri notes”? This is a specialized term frequently used in wine tasting, particularly when evaluating aged Riesling wines. Experienced tasters can sometimes identify a wine’s grape variety as Riesling the moment they detec …

grape-disease viticultur

2025/7/29

The Three Major Diseases of Wine Grapes | Downy Mildew: Causes and Control Measures

There is one disease that grape growers particularly fear during rainy years: downy mildew. Whether dealing with wine grapes or any other cultivated plants, the battle against diseases is unavoidable. Vineyards encounter various diseases, but the most pro …