How to compare moisture, grade and size in bulk prunes

Start with the prune style and what the count represents

A size label is useful only when its counting convention is clear. Prunes are often sized by the number of fruits per pound, but buyers should not assume every supplier or specification uses the same unit or counting rules. Ask whether the stated count refers to whole fruit as received, and whether it applies to pitted or unpitted product. Pitting changes fruit weight, so the two styles should not be compared by count without checking the basis.

Specify the physical style separately from size: whole, pitted or unpitted, and any required appearance or processing condition. If the product will be sold or packed as visible fruit, shape, skin condition and consistency of size may matter. If it will be chopped or further processed, a tight whole-fruit size range may be less important than the condition of the fruit and the downstream cutting or blending step.

Read grade as a description of defects—not a size label

Grade and size answer different questions. Size describes fruit dimensions or count under a stated convention; grade describes quality factors such as condition, uniformity and the presence of defects. A larger-count fruit is not automatically a higher grade, and a grade name alone does not establish a particular size.

Make the defects that matter explicit. Depending on the product and use, buyers may need to evaluate damaged or misshapen fruit, skin defects, stems, foreign material, and the presence of pits in a pitted style. The specification should say how defects are defined, how they are assessed, and whether limits apply to individual defect types or a combined total. Request the actual grade definition rather than relying on a grade label without its criteria.

Compare moisture on the same basis

Moisture affects the character of dried fruit, including softness and handling, but a moisture figure cannot be compared fairly unless its basis and test details are clear. On a wet basis, water is expressed relative to the sample as received; on a dry basis, it is expressed relative to the dry solids. The same lot can therefore have different stated percentages on these two bases.

For a meaningful comparison, identify the test method, sample preparation, reporting basis and whether the result is a lot specification or a measured result for the offered lot. Moisture content and water activity are different measurements; one should not be substituted for the other when a process or finished-product requirement calls for a specific test. Also consider how the fruit’s moisture and texture behave in the intended application and package, rather than treating a lower number as automatically better.

Treat low-moisture prunes as a separate specification

Ordinary dried prunes and separately specified low-moisture prunes should not be evaluated against one assumed moisture limit. A low-moisture designation describes a distinct product requirement, not a universal grade or a guarantee of a particular texture, shelf life or packaging condition. The applicable limit and test basis need to be stated for the specific offer.

If a process requires low-moisture fruit, define the acceptable moisture measure and test method, then check that the product’s style, texture and packaging are also appropriate. If the requirement is driven by a formulation or process-control target, have the technical specification identify the exact measure used to accept the lot. Do not compare a supplier’s result with a limit unless both refer to the same basis and method.

Build a specification that can be checked at receiving

A useful bulk prune specification names the style, sizing convention and unit, grade criteria, defect limits, moisture limit and basis, and required test method. It should also state how the lot will be sampled and which records or analysis accompany the shipment. These details let purchasing, quality and receiving teams compare offers on the same terms instead of trying to reconcile broad labels after delivery.

Before accepting an offered specification, verify that the current document applies to the product and lot being quoted. Ask for the lot’s size/count definition, grade criteria and moisture result with its reporting basis and method; check whether the document describes a guarantee, a typical value or a test result. Once those comparison points are set, use the [prunes ingredient page](/ingredients/prunes) to continue sourcing the form that fits your process.

Common questions.