Characteristics of strawberry wine

Wine can be produced from a variety of substrates (fruits) such as strawberry, cherries, apple, and pomegranate and the produced wine is popularly known as fruit wine.

Among all the fruit wines strawberry have a unique desirable flavor which makes it one of the most popular summer fruit. Sugar and acids provide sweetness and tartness, whereas volatiles compounds give the fruity characteristic aroma.

Seventy-eight volatile compounds were found in the strawberry wine, including 25 alcohols, 25 esters, five ketones, four aldehydes, nine terpenes, four acids, five phenols, and one styrene. During the fermentation, the composition of aroma compounds changed over time.

A typical wine contains sugars, acids, ethyl alcohol, higher alcohols or fusel oils, tannins, aldehydes, esters, amino acids, minerals, vitamins, anthocyanin, fatty acids, minor constituents like methanol, a number of flavouring compounds, etc.

Considering their relatively low odor threshold and diversity, esters are positive contributors to wine flavor, especially in young wine.

Wines made from more mature fruits had greater colour intensity and higher levels of anthocyanins. Anthocyanin content in carbonic macerated free run wines showed higher value compared to those skins fermented or pressed wines.
Characteristics of strawberry wine

Sulfur dioxide as food additive

Sulfur dioxide has been used since olden times in the form of 1-2% aqueous solutions as a disinfectant for equipment, barrels, bottles, corks and other ancillary items for the wine, drinks and food industries.

Fumes of burning sulfur were used as a sanitizing agent in wine-making by the ancient Egyptians and Romans. The practice is continued by the modern wine industry.

The compound is a colorless, nonflammable gas or liquid under pressure, with a suffocating, pungent odor.

Sulfur dioxide is used to prevent browning in certain dried fruits and to prevent wild yeast growth in wines used to make vinegar.

Sulfur dioxide also is used to control the growth of undesirable microorganism in soft fruits, fruit juices, wines, sausages, fresh shrimp, and acid pickles and using extraction of starches.

It is added to expressed grape juices used for making wines to inhibit molds, bacteria, and undesirable yeasts.

The most obvious drawback of sulfur dioxide is its intense pungent odor, which may be apparent in foods it is used to treat.
Sulfur dioxide as food additive

Aging process of wine

After alcoholic fermentation, aging is the next most major important stage of the wine production process. Aging changes the character of a wine in many of the same ways that it changes the character of human beings: they become deeper, more mellow and more complex.

Based on the style of wine, aging time may vary, and it may be a few months to several years.

Traditionally, aging is carried out in oak barrels that are stored in damp cellars where humidity protects the barrels from drying. Aging in barrels may also be for only a limited time and then the wine may be transferred to larger casks or tanks for further aging.

Biological aging 
There are two main types process for aging: biological aging and oxidative aging. The biological aging process involves various changes in wine composition.

Such changes are essentially the result of the metabolism of flor yeast and to a lesser extent, of other phenomena common to all types of aging processes including crystal precipitation, chemical reactions between wine components and extraction of substance from cask wood.

During this time, the wine undergoes malolactic fermentation and often develops a thin layer of yeasts on its surface.

Flor yeasts can undergo autolysis during biological aging of wine. This biochemical process occurs under special conditions such as those in wines stored and aged in contact with yeasts for months or even years. The yeast coming from either from grapes or previously used barrel.

Oxidative aging 
The oxidative aging occurs without flor yeast activity. During the aging process, some of the substances responsible for the fruity character in the one are oxidized by oxygen.

Barrel wood plays a role as a type of tissue of semi-permeable membrane to oxygen, allowing it to be incorporated into the wine at just the right rate.

A small amount of oxygen in an aging wine helps tannin, molecules polymerize and settle, softening a wine’s body and making it less bitter.

The aging process improves the overall quality of wine, including aroma, color, clarity, taste and mouthfeel. 

Different flavor and aroma enhancing compounds are formed during aging, and in the traditional aging process, the wooden barrel used for storing the wine also contributes to improving the flavor; especially, gives an oaky flavor to aged wine. The aging of wine success depends on a number of physical, chemical and biological factors.
Aging process of wine