Seedless Grape Origins

Originally recognized as "Sultanina," the Thompson Seedless grape is thought to have originated in Persia, encompassing parts of present-day Iran and Turkey. Humans have transported it through various temperate climates, and more recently, it has been cultivated in subtropical regions.

Between 120 and 900 BC, the Phoenicians planted vineyards in Spain and Greece, while Armenians did so in what is now Turkey, Iran, and Iraq. The seedless grape variety was later named after William Thompson, who first cultivated these grapes in California around the beginning of the twentieth century.

The cultivation of the grape spread across Asia Minor, the Mediterranean, and northern Africa, reaching Europe and subsequently finding its way to America, South Africa, and Australia. Spaniards introduced it to Mexico and regions now part of California and Arizona. English settlers brought the Old-World grape to the colonies along the Atlantic seaboard.

In 1872, William Thompson of Yuba City introduced the seedless grape to California, obtaining cuttings from the Elwanger and Barry nursery in Rochester, New York. Initially labeled as a grape from Constantinople grown in English hothouses under the name 'Lady De Coverly,' local planters quickly embraced the misnomer 'Thompson Seedless,' a name that persisted throughout its use in California. The variety is also recognized as 'Sultanina,' originating from 'Sultanieh.'

By the 1840s, the emergence of railways facilitated the shipment of grapes from southern to northern states, extending the availability of grapes in the summer. By the 1880s, California had become a significant source of table grapes for eastern markets.

Before the introduction of Thompson Seedless grapes in 1876, the grape industry faced challenges due to the tedious process of seeding common muscat raisins. The introduction of seedless grapes contributed to the flourishing of the industry.
Seedless Grape Origins

Concord grapes: Vitis labrusca

The Concord grapes is a robust grape cultivated from ancestral native species or a derivatives of a wild Vitis labrusca grape that could withstand the harsh New England weather. Concord grapes were first developed near Concord, Massachusetts by Ephraim Wales Bull in 1849.

It grew from a seed planted in 1843, which bore fruit in 1849. Prior to the appearance of the Concord, grape growing in Eastern American had limited success.

The only sugars are found in Concord grapes are glucose, fructose and sucrose, and the major nonvolatile acids found were tartaric and malic.

The Concord grape variety is chiefly used for the manufacture of grape juice. Approximately 96% of the juice made in New York state is prepared from Concord Grapes. Natural acidity, color and aroma of fresh grape berries provide quality in single strength Concord grape juice. Acidity above 0.85% results in juice that is too tart.

Hot pressing of the grapes is important to extract anthocyanin pigments, flavor components, amino acids, organic acids, sugars, minerals, tannins, and other ingredients.
Concord grapes: Vitis labrusca

Processing of Raisins

Processing of Raisins
Raisins are produced from grapes by sun during and artificial drying. In sun drying, the grapes are picked as bunches and placed in a single layer on wooden trays between the rows of grapes vines. The trays are tilted to face the sun. After they are partially dried, the grape bunches are turned and allowed to dry to the point where no juice can be pressed out. The trays are then stacked, and the air drying is continued in the shade until moisture content of about 17% reached. After drying, the raisins are placed in sweat boxes to equilibrate, or to even out, the moisture that is present, and then they are packed in retail size containers or in larger containers to be sold to the bakery trade.

In artificial drying, grapes are first dipped n 0.25 – 1 % lye (sodium hydroxide) solution at 200 – 212 degree F for 2 – 5 sec to remove a natural wax that impedes drying and to check or crack the skin of the grape to facilitate drying, They are then washed, placed on trays, and treated with sulfur dioxide to prevent enzymatic and nonenzymatic browning during drying. Hence instead of having the dark brown color of raisins that normally be expected, the raisins will be of a light yellow color when dried. Raisins are dried at temperatures not exceeding 165 degree F and at a low relative humidity. After the moisture content has been lowered to about 16 – 18%, the raisins are packaged in containers of various sizes to be sold at retail or for use by the food industry.
Processing of Raisins

Wine and Wine Vinegar from Grapes

Wine and Wine Vinegar from Grapes
Considerable quantities of wines are manufactured in the United States. The European varieties of wines are mainly used for making wines. The various procedures are used in the production of wines. The pressed juice method usually used after treatment with sulfur dioxide or compounds that liberate by natural yeasts surviving the sulfur dioxide treatment. During fermentation, sugars are converted to ethyl alcohol until a level of 12-14% alcohol, and these may be used as such for fortifying wines to obtain higher alcohol content.

In manufacture of wine vinegar, fermented grape juice (containing alcohol) is allowed to drip over wood shavings in an enclosed cylindrical container. The shaving previously soaked in a high quality vinegar. Air may be introduced into the generator under pressure, bacteria of Acetobacter group present (from the vinegar) on the shavings convert the ethyl alcohol in the wine to acetic acid.

The effluent from the vinegar generator may be collected and recycled to obtain a complete conversion of the ethyl alcohol. The finished vinegar may be stored for several months at 40 – 50 degree F, then filtered, bottled and pasteurized.
Wine and Wine Vinegar from Grapes

Grapes

Grapes
In the United States, grapes are grown mainly in California, New York, Pennsylvania, Michigan and Ohio. Washington, Missouri, and Arkansas also produce same grapes. There are many varieties of grapes but there are predominant in this country. Grapes are utilized to produce unfermented grape juice, vinegar, wine, raisins, jams and jellies, and as the fresh product for table. Grapes are planted as vines or cuttings from older plants. The cuttings produce arms bearing fruit, the greatest yields coming after 3 years of growth. Properly pruned and cared for, vines produce fruit for many years.

Grapes to be shipped as fresh are packed in wooden crates, then precooled to about 40F (4.4 C) in railroad cars or refrigerated rooms. Generally, the grapes will be fumigated with sulfur dioxide prior to or during cooling to prevent mold growth. Grapes that are to be stored for future shipment should be packed in crates, precooled to 36 – 40 F (2.2 – 4.4 C0 placed in refrigerated storage, and fumigated with sulfur dioxide, they should be held in this manner until shipped. Periodic refumigation with sulfur dioxide may be required to prevent spoilage by molds. Under these conditions, grapes have a storage life 1 -7 months depending mainly on the variety.
Grapes