Method of making raisins/dry dehydrate Grapes:

  Raisins are natural healthy snacks, containing a variety of minerals, vitamins, and amino acids. It can be eaten alone or added to various foods, such as making oatmeal raisin cookies. The method of making raisins is very simple. You can easily make raisins by putting them in the sun or putting them in the oven. The traditional drying method is to dry in the sun, but the raisins are prone to sour, poor color, and easy to emit sugar. At present, dryers are often used to dry grapes, instead of traditional drying methods. Next, let us learn the specific steps of the various methods.

The traditional method of making raisins:

• 1. Remove the larger stalks, and then wash the grapes with water.
• 2. Arrange the grapes evenly on the baking tray, cover the grapes with a cloth, not only to drain the grapes but also to prevent insects from approaching.
• 3. When the weather is hot and dry, place the bakeware in the sun. Sun grapes only when the weather is hot and dry. The hotter and drier the weather, the easier it is for the grapes to dry. When the weather is cool, cold, or particularly humid, the grapes need to be dried for a longer time, and may not even be dried completely. If the place where you live in foggy or dew at night, bring the bakeware back to the house after dark and put it outside to dry the next morning.
• 4. Put the grapes in the sun for 3-4 days and turn them over frequently to ensure that each side is exposed to the sun. After 3 days, you can taste whether the grapes are dry enough. If you are satisfied, you can take them back to the house. If it is not dry enough, you can dry it for another day. The grapes are sun-dried for up to 5 days, not more than 5 days.
• 5. After the raisins are dried, put them in an airtight container, and put the container in a cool place or the refrigerator.

Making raisins in the oven

• 1. Wash the grapes and remove the larger stalks.
• 2. Put the grapes evenly on the baking tray. Adjust the oven temperature to about 110℃, preheat for 15 minutes before putting the grapes in, otherwise, the quality of the raisins will be affected, and then bake in the oven for 4 hours. It can also be baked at 65℃ for 36 hours. Although it takes a long time, it reduces the risk of drying too much.
• 3. During the roasting process, check the grapes more. If the grapes are dry enough, you can take them out even if they have not been roasted for 4 hours. The specific roasting time depends on the size of the grapes and the degree of dryness you like.
• 4. Take the raisins out of the oven and let them cool for 30 minutes. Put the raisins in an airtight container and put them in the refrigerator. Raisins can be refrigerated for up to 3 weeks.

Hint：

1. Overripe grapes will take longer to dry, so it is better to choose grapes that are about to ripen and have a sweet taste.
2. Pay attention to whether the grapes are wet or rotten.

How to making raisins/dry dehydrate Grapes in large quantities with a dryer:

1. Choose fresh seedless grapes with thin skin, soft flesh, and sugar content above 20%.
2. Use 1.5-4.0% sodium hydroxide solution to clean grapes to wash away the wax and harmful microorganisms attached to the peel. At the same time, it can be disinfected and cause small cracks in the peel to facilitate the evaporation of water and promote drying.
3. Drying:
The initial temperature is between 40-50℃, the time is 2 hours, and the skin moisture evaporates.
The mid-term temperature is 55℃ and the time is 10 hours. At this time, the grape dehydration rate is about 70%.
Deep drying, heat up to 60℃, strengthen dehumidification, humidity is 55%, time is 10 hours.
The latter temperature is 55℃ and the time is 5 hours. At this time, the moisture content of the grapes is less than 12%.
4. Classification according to color and sweetness, packaging, storage, and sale.

Precautions:

  The roasted grapes must be ventilated and dissipated and can be stacked together after cooling. If the grapes just taken out of the drying room are piled together, the raisins are prone to spoilage. Therefore, after drying, it must be completely cooled before storage.

  If you want to produce raisins in large quantities, Baixin Machinery’s drying equipment is a good choice. Baixin Machinery is a manufacturer specializing in the production of dryers. It has 20 years of rich experience. For grapes drying, it has professional drying equipment and mature drying technology to ensure the perfect drying effect.

  Baixin Machinery’s most popular grape dryers are heat pump dryers and continuous mesh belt dryers.I would be happy to introduce these two dryers in detail for you:

1:The first method:grape heat pump dryer

Household Commercial All-in-one drying equipment without installation for any material
  Drying essence is take moisture away, but takes away the moisture temperature is not the most critical factor. The key for drying is depending on relative humidity within certain space, Baixin Company took advantage of the dry essence, originality developed a "Closed Cycle" dryer, changed the traditional heat pump dryer "bake" to "dehumidifier”. Its several advantages were unmatched by the traditional heat pump dryer.
  Baixin Food Dehydrator has a compact structure, great energy-saving, wide application, high drying quality, easy operation, simple installation and removable. it is the best drying equipment for small firms, drying experiment and scientific research. The users only connect the power to use, is the easiest operation heat pump dryer.

2:The second method: grape continuous mesh belt drying machine

Large amount of dehydration 200-5000kg/h grapes drying machine continuous automatic work easy operation
  Grapes dryer machine is a kind of continuous production drying equipment, the main heating way has electric heating, steam heating, hot air heating. Its main working principle is to spread the material evenly in the network. The material is moved in the dryer by the operation of the machine, and the hot air draws out the water vapor of the material. so as to achieve the purpose of drying.
  The operation temperature is 40-120 degree centigrade. And the dry cycle is 1-5 hours.

Grapes drying video：