Lewatit, Lewabrane, wine, reverse osmosis, ion exchange resins, red wine, white wine, LANXESS, Lanxess

From the vine to wine

It’s a Saturday afternoon. Anja is relaxing in the garden. While she sits soaking up the warm sunshine, her husband Martin puts their lunch on the grill. The alluring aroma of grilled trout wafts towards her. Keenly anticipating their meal together, she pours herself and her husband a glass of dry white wine. It has a pleasing hint of apple and lemon, and a delicate, golden yellow hue. When Martin brings the fish, they drink a toast to each other and take a nice long sip.

For many people, a good wine is a key ingredient of a decent meal. But what is it that gives the fruit of the vine its typical color and great taste?

Winemaking is a natural, yet complex, process. After all, the quality and properties of the grapes vary from year to year due to weather and soil conditions. To ensure that the quality of wine remains consistent, winemakers can use certain “tools” in the production process. The Code of Oenological Practices regulates where these tools can be used. It is a sort of “law” that tells vintners which measures can be applied for wine correction.

Machine grape harvesting.
The berries are crushed in a kind of mill. The mash is created.
The mash rests for a few hours or days, depending on the wine. Then it is pressed.
Fermentation in stainless steel vessels. During fermentation, the sugar contained in the must is converted into alcohol.
Ageing of the wine in barrirque barrels.
Verification of wine quality.
Bottling of the wine.

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Let’s take a look at the production process:

The grape is the only fruit with the ingredients required to give wine its typical taste. For instance, these substances make the wine dry or provide a bitter taste.

These days, grapes are usually harvested mechanically. After harvest, the grapes are crushed in a mechanical wine press, resulting in what is called the must.

For red wine, a must consisting of grape juice and grape skins is prepared. By contrast, the grape juice alone is fermented when making white wine.

During the fermentation process of dry wine, the sugar is converted to alcohol. In the production of sweet wine, the winemakers stop this process before all the sugar has turned to alcohol. Once the wine has matured in storage tanks or barrels, it is poured into bottles.

To ensure high-quality wine, LANXESS products are used. For example, Lewatit^® ion exchange resins and Lewabrane^® reverse osmosis membrane elements help with

Wine stabilization,
Improvement of flavor and
Alcohol adjustment.

Wine stabilization

Did you know that the actual process involved when using Lewatit^® ion exchange resins is contained in the name? Ion exchange resins can be used to prevent the formation of tartrate crystals. We are all aware that our drinking water contains potassium, calcium, sodium, and other ions, and that we need certain quantities of these ions (or minerals) for our metabolism.

Well, your favorite wine also contains ions such as potassium, calcium, and sodium. But tartrate is formed only if potassium or calcium bind with the tartaric acid. It is basically present in dissolved form in every wine. It can coalesce into large, visible amber-colored crystals as a result of storing wine at low temperatures, for instance. Whether and how much tartrate is formed also depends on the vintage and the alcohol content.

Imagine that potassium and calcium are simply removed from the wine by being exchanged for sodium ions. Ion exchange resins in the Lewatit^® product line can do just that. They remove potassium and calcium from the wine, replacing them with sodium, and Anja and Martin no longer have any tartrate crystals in their wine.

Although the producers can intervene at several points in the process, they do so only when necessary. The aim is to provide a wine made as naturally as possible with an outstanding taste.

Improvement of flavor

All finished table wines contain acids, but not every acid in the wine leads to a good taste experience. Have you ever tried pure vinegar? Too much vinegar in your salad spoils it. It’s similar with your favorite wine.

Most of the acids found in balanced wines (Tartaric, Malic, Citric, Acetic, and Lactic ) are fixed acids which originate in the grape juice, remain throughout the fermentation process and add to the style, balance and taste of the finished wine.

Tartaric and Malic acids are the major wine acids. Tartaric is the strongest of the grape acids, responsible for much of the tart taste of the wine and contributes to the biological stability and longevity of the wine.

Acetic acid is significantly different from the fixed acids (Tartaric, Malic) found in wine which can add a distinctive vinegar odor to the wine. Balanced wines normally contain very little acetic acid. Small amounts of acetic can enhance the bouquet of the wine by producing a somewhat sour essence to the taste of the wine as is the case with a salad, however, excessive amounts of acetic acid can cause an accentuated sharpness or sourness and in an extreme turn wine into vinegar.

Lewatit^® ion exchange resins can solve the problem and ensure that Anja and Martin have a wine with just the right acid composition to go with their trout dish.

Alcohol adjustment

Winemakers often let the grapes mature until the optimum flavor is attained. Sometimes, the grape juice contains too much sugar. After fermentation, this results in a high alcohol content, which is undesirable because the taste of alcohol suppresses other aromas in the wine.

Membranes in the Lewabrane^® product range can be used to reduce the alcohol content. Conversely, the alcohol content can also be increased via membranes. For instance, it is possible in principle for Anya and Martin to buy their favorite wine each year with the same alcohol content—regardless of the weather while the grapes ripen.

Although the producers can intervene at several points in the process, they do so only when necessary. The aim is to provide a wine made as naturally as possible with an outstanding taste.

So, Anja and Martin: bon appétit, and cheers!