Concord Grape Juice Production: A Step-by-Step Process

The Concord variety of grape, primarily used in the manufacture of grape juice, undergoes a precise, multi-step process to ensure quality and safety. Initially, the grapes are thoroughly washed using an acid or alkaline solution to remove any pesticide residues. They are then rinsed with water, destemmed, and crushed mechanically.

Once crushed, the grapes are heated to approximately 180°F to extract pigments from their skins, which gives the juice its distinctive deep color. The heated grape material is then placed in cotton press cloths and subjected to mechanical pressure to separate the juice from the pulp.

After the juice is extracted, it goes through a filtration process to remove solids and impurities. To ensure safety, the juice is pasteurized by heating it to around 179°F. Following pasteurization, it is stored in bulk in covered tanks at a cool temperature of about 40°F. This low temperature promotes the separation of tartaric acid salts (tartrates), which can crystallize and settle at the bottom of the tanks. Once this process is complete, the juice is siphoned off, leaving the tartrate behind.

For further clarification, the juice is treated with enzymes to break down pectin, a substance that can cause cloudiness, or with casein, which aids in achieving a clear product. The clarified juice is then filtered again and bottled. The bottles are sealed and pasteurized a second time by heating them in water at 170°F for 30 minutes.

To produce grape juice concentrate, the juice is subjected to heat and evaporation, which reduces its water content and increases the concentration of flavor and sugars. During this process, volatile components, which contribute to the flavor, may be recovered and added back to the concentrate. The concentrate is either frozen in retail-sized containers or shipped in bulk to food processors for further production.

This careful process ensures the production of high-quality grape juice and concentrate, preserving flavor while maintaining food safety standards.
Concord Grape Juice Production: A Step-by-Step Process

Concord grape fruit juice

Most of the unfermented grape juices consumed in the United States is made from Concord and Niagara grapes.

Grape juice concentrate is used frequently as a food ingredient and has the advantage of being a means of adding sugar to other products in a natural form. 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.

The quality of grape juice can be described almost entirely by its chemistry. Juice color is caused by anthocyanins, their glucosides and condensation products, its taste, by acids, sugars and phenolics and its aroma by diverse moisture of volatile secondary metabolites in very low concentration.

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

Today Concord grapes are grown in the US states of New York, Pennsylvania, Ohio, and Michigan, with the largest producer being Washington.
Concord grape fruit juice