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