Processing Details

The production and manufacturing of California Raisins for consumption is a fascinating process. Understanding all the aspects of raisins, the products made from them, benefits of their use, and the differences as they are manufactured – all that information resides right here.

Storage

Temperature

California Raisins may be stored at room temperature without noticeable loss of color or flavor for a few months. The stability at room temperature will be dependent upon the moisture levels of the raisins and the relative humidity of the atmosphere. If the storage room temperature exceeds 10ºC (50ºF), the relative humidity should be kept below 55%. Raisins should be stored away from grain products such as wheat flour and corn meal. If the storage room temperature and relative humidity are high, refrigerated storage may be adopted for short periods of time.

Relative Humidity

The optimal relative humidity for storage of raisins is in the 45-55% range. Raisins then neither gain nor lose moisture. Controlling the relative humidity is particularly critical if the storage temperature is not optimal. Lower temperatures slow the moisture transfer rate from the air to the raisins. Poly-bags and proper packaging help to protect raisins in high humidity conditions.

Purchasing Specifics

  • Parent Grape: Seedless
  • Description: Naturally sun-dried.
  • Approximately 2000-2400 berries/kg (1000-1200 berries/lb.)
  • Packaging: Available in 12.5 kg cases, 11.3, 13.6 and 18.1 kg containers (25, 30 and 40 lbs.)
  • Availability: Excellent supply year-round.

California Raisin Storage & Handling Tips

  • Controlled, cool storage is the best way to keep raisins. Raisins will retain their color, flavor and nutritional value for up to five months if stored at 45° F or less.
  • To maintain optimum freshness, keep raisins sealed in an airtight container in the refrigerator or in your coolest storage area.
  • Raisins freeze well for long periods of time. They also thaw quickly at room temperature for a quick, convenient and healthy snack.
  • When raisins become dry or when a recipe calls for plumped raisins, cover the amount needed with very hot tap water and soak for 2 to 5 minutes. (Do not soak any longer than five minutes. Flavor and important nutrients can be lost.)
  • When chopping raisins, always use a lightly oiled knife or blade.

Benefits of California Raisins

From their consistent color and flavor, to extending product shelf life, there are many advantages to using California raisins regularly in your recipes. We’ve outlined a few of those below

Characteristics Value Benefits
Natural No surface treatment is used to aid in drying. The drying process is all-natural, performed 100% in the sun.
  • Consistent color and flavor
  • No chemicals, no additives
  • 100% natural
Structural Integrity Because of hand harvesting and sun drying the California raisin develops a firm, unbroken skin.
  • Holds up to manufacturing processes
  • Will not collapse
  • Builds volume
Consistency Careful harvesting and state-of-the-art processing ensure a consistent product crop to crop year.
  • Consistent chewiness
  • Meaty and firm
  • Substantial particulate
Sweetness Natural sun drying creates a sweet and fruity morsel. Sugar/Acid Ratio: 40:1 (approx.)
  • An intense natural sweetener
  • High fructose content
  • Fruity taste
Humectancy Natural sun drying creates a consistent moisture content. The water activity is low.
  • Inhibits staling
  • Softens products
  • Extends shelf life
Color Natural sun drying creates a consistent dark bluish/black color.
  • Natural caramel color
  • Won’t bleed
  • Adds visual contrast
Chemical Properties Naturally occurring organic acids provide valuable side benefits to manufacturers. Tartaric acid: 1.5-2.2%, propionic acid.
  • Enhances flavors
  • Inhibits mold growth
  • Natural preservative
Quality Control Quality backed by strict inspection procedures makes CA raisins tops in the world.
  • Aflatoxin negative
  • Low microorganism count

Processing

Processing of California raisins involves a multi-faceted process, including inspection by the USDA to ensure the raisins meet federal standards. Part of the crop is selected to make raisin juice and raisin paste for commercial applications.

Before raisins are unloaded, government inspectors gather samples from the middle of each box to make sure they are free of imperfections.

Then they’re “processed”, size-graded, washed in pure water and moved through a laser sorter to remove any unwanted material.

After final inspections, raisins are automatically weighed and packed in a variety of convenient sizes and shipped around North America and the world.

Part of the crop is used to make raisin juice (a minimum of 70 percent natural fruit soluble solids) and raisin paste (made from 100 percent raisins), which are added to a variety of foods, including dairy, confectionery and bakery items.

Raisin Juice Concentrate

From part of the crop, the processors make raisin juice and raisin paste. Raisin juice is a pure extract of raisins. Throughout several processing stages, raisins are leached with water to produce raisin juice. The liquid then is evaporated in a vacuum pan to produce a self-preserving concentrate. Raisin juice concentrate contains a minimum of 70 percent natural fruit soluble solids. It’s added to a variety of foods, including dairy, confectionery and bakery items. Raisin juice extends the shelf life of bread products; it is a natural substitute for preservatives; and it sweetens and colors natural baked goods. For confectionery items, raisin juice acts as a sugar substitute and a filling for hard candies and molded chocolates. In crisp cookies and crackers, raisin juice helps control breakage. With chewy or soft cakes and cookies, the raisin juice can help maintain moisture. It also is a natural binding agent in cereal bars. Raisin juice serves as a natural syrup for yogurts and ice cream. It enhances the color and flavor of chocolate milk and ice cream. It also brings out the flavors of condiments and is an all-natural coloring agent.

Characteristics

  • Color: Amber to dark brown
  • Flavor: Inherent fruity flavor
  • Viscosity: 260-500 cp at 21ºC (70ºF)
  • Weight: 1.35 kg/liter (11.25 lbs/gallon) at 70º Brix
  • Specific gravity: 1.348
  • pH: 2.0 to 3.5
  • Rich in tartaric acid (2%) and propionic acid (about 500-600ppm)
  • Reducing sugars: 85 to 90% of dry solids
Applications
Bakery
  • Extends the shelf-life of bread products
  • Sweetens and colors natural baked goods
  • A natural substitute for preservatives
Confectionery
  • A sugar substitute
  • A filling for hard candies and molded chocolates
Snacks
  • Controls breakage in crisp cookies and crackers
  • Maintains moisture in chewy cakes, soft cookies
  • A natural binding agent in cereal bars
Dairy
  • Natural syrup for yogurts and ice cream
  • Enhances the color and flavor of chocolate milk and ice cream
Condiments
  • Enhances the flavors of sauces
  • All-natural coloring agent

Availability

  • Raisin juice concentrate is available in 18.9 liter pails (5 gallons), 208 liter drums (55 gallons) and tank cars.
  • 18.9 liter pail:
  • Net weight: 26.5 kg (59 lbs)
  • Gross shipping weight: 28 kg (62 lbs)

Storage

Because of its low pH, high sugar and soluble solids content, raisin juice concentrate is self-preserving. It is recommended that it be stored at temperatures between 15º and 21ºC (60º to 70ºF). Although, extended storage may affect its color and flavor, this change is slow.

Composition

Nutrients
Carbohydrates (total by difference) 68.00 g
Sugar (reducing sugar) 65.00 g
Protein (N x 6.25) 2.10 g
Ash 0.60 g
Fat 0.20 g
Fiber 0.02 g
Total Acid (tartaric) 2.00 g
Nutrients / 100g Energy 225Kcal/100 g
Minerals
Sodium 25 mg
Potassium 110 mg
Calcium 37 mg
Magnesium 37 mg
Phosphorus 99 mg
Iron 3 mg
Copper 0.2 mg
Zinc 0.2 mg
Vitamins
Vitamin C 3.70 mg
Niacin (by microbiological assay) 0.80 mg
Riboflavin (by microbiological assay) 0.02 mg
Thiamin 0.10 mg
Vitamin A 5.00 IU
g = gram, mg = milligram, Kcal = kilocalorie, IU = International Unit

Quality Assurance

The Finest From California

It’s August in the San Joaquin Valley. Another bountiful season is coming to a close. Trucks are taking loads of raisins from the farmers’ yards to the packing plants – a mark of the season’s end.

Before raisins are unloaded from their bins, government inspectors take long prods to gather samples from the middle of each box. United States Department of Agriculture (USDA) standards must be met to ensure that each box is free of imperfections. Next, raisins are processed, which means they go through a series of conveyor belts and drums to remove remaining stems, chaff or lightweight fruit. The raisins also are sent through a vacuum air stream to catch any other undesirable materials. Finally, they’re size-graded and thoroughly washed in pure water. In preparation for packaging, the raisins are moved through a laser sorter. The sorter’s light beams, along with a computer, see if anything besides raisins is passing through the stream. If material other than a raisin is present, the computer sends a burst of air to knock it out of the stream of raisins and down a trough. California raisins are inspected under the most rigid standards. Quality control technicians inspect the raisins by hand throughout the packing process, thus assuring that California raisins are the cleanest, highest quality in the world. After final inspections, raisins are automatically weighed and packed in a variety of convenient sizes. California raisins are then shipped around North America and the world for consumers to enjoy.

Question & Answer

Q. How many raisins to lb/kg?
A. 1000-2000 raisins/lb (2,000-2,400/kg)

Q. Package sizes?
A. 25, 27.5 and 30 lb containers (11.3, 12.5 and 13.6 kg)
Other package sizes are available, contact a packer

Q. Water activity of raisins?
A. At 25° C, water activity is 0.51-0.56 at 13-15% moisture and 0.55-0.62 at 15-18% moisture.