The sultana is a white oval seedless grape variety also called the Sultanina. It is also the name given to the raisin made from it or from larger seedless grapes; such sultana raisins are often called simply Sultanas or Sultanis. The Sultana is grown mainly in and around the northern region of Karnataka. DSK’s facility is strategically placed in Vijaypur where the best quality sultanas are grown. Once the grapes are ready for harvesting bunches are cut from the vine and are dipped in a solution of water, oil and potassium carbonate which accelerates the drying process. After the application of the solution bunches are placed on the rack to dry naturally. An average Sultana takes 7/10 days to dry whereas the Thompson that is not dipped in the solution takes around 20/25 days to dry and is also darker in color than the conventional Sultana. Depending on the weather conditions and the harvest in the North Karnataka region bunches are cut from the vines to be dried in natural conditions around February of every year.
Sultana is dried in the shade by using thenet to protect them from direct sunlight to natural sun drying. The drying period takes around 10 to 12 days depending upon the temperature. After drying, the Sultanais removed from the shade and sent to the production unit for further grading, sorting and packaging.
The production management starts from the initial stage of pruning and harvesting where proper inspection and quality control is done through every stage of the same. Pruning is done in October and it takes 120 days to harvest after that. Once the grapes are ready to harvest, they are cut with scissors with manual labor and are filled in plastic crates and brought to the drying area where they are dried in shade. After drying, the initial part of the process starts with the raw material being placed into the hopper. Once the raw material has passed the hopper, it is transported via conveyor belts which pass through magnets to remove any metallic foreign elements to the Dry Capstemmer. The Dry Capstemmer uses centrifugal force to remove the capstem which is attached to every berry in the bunch.
After this process is complete the Sultanas are transported to the second section of DSK's facility, the Washing Department.
In the Washing Department of DSK's factory the raw material travels under several aspirators which remove minute foreign materials such as stems, branches and stalks.
After the Aspiration Process, the sultanas are submerged in Chlorinated Water for Sterilization. In order to remove any heavier foreign material from the sultanas the sultanas are transported to the cascade washer via water pumps. This process uses the flow of water and the pull of the gravitational force to remove materials such as stones. To achieve the maximum level of cleaning, the semi-processed material is placed in to the Wet Capstemmer.
After the oiling process, the raisins are split into two different lines and then four different lines the two different lines are split into four lines under the aspirators. As DSK focuses on quality based facility, before the sultanas are further sent to the Mechanical Sorting Department, the produce is tested by experienced workers who visually inspect the Sultanas for any foreign material and non-conformities in or on the Sultana.
The Sultanas that have passed through the Laser Scanners then go into the X-ray Scanners. The X-ray Scanners are used to identify any foreign material that may be embedded inside of the berry. The second function of the X-ray is to reject any Quartz Crystals in the product. This second function is used because in some conditions due to reflective and refractive qualities of the Quartz Crystal, the Laser Scanners have been known to miss these crystals. Once the X-ray scanners have cleared the Sultanas they enter the final stage of DSK's process. Next in the Metal Detection and Weighing Station the almost ready Sultanas are passed through an Online Throat Metal Detector which then if cleared only moves them on to the highly sensitive Weighing and Boxing Station. Once the boxes are filled to the correct weight they are closed and sent under an Online Case Metal Detector. This process is to identify any foreign metallic material that may have been in the corrugated box.