Blackberry is structurally a cluster of small drupelets held on a core, and that structure is what makes it fragile. The quality question on a frozen lot is not the calibre of the berry but whether the drupelets are still attached to each other after freezing, handling and transport. A lot that arrives as loose drupelets and cores is technically the same fruit and commercially a different product. Whole grade is bought for visible use and crumble for processing, and the grading definition has to say what proportion of intact fruit the whole grade actually contains.
Seasonality and availability
Harvest runs from July into September. Cultivated blackberry dominates commercial volume. As with the other soft berries, the product is frozen at harvest and drawn from store through the year, and the fruit frozen at the peak of a heavy week is the fruit most likely to have had a slow temperature pull-down, so ask about tunnel loading if the lot will be used in a visible application.
What the buyer checks at intake
- Drupelet integrity on a weighed sample. Count intact fruit rather than judging by eye.
- Core temperature at minus eighteen degrees Celsius or colder.
- Colour, including the proportion of red or underripe fruit against the tolerance.
- Free-flowing behaviour and clumping.
- Free ice and glaze in the bag.
- Foreign vegetable matter and stalk content.
Related standards and routes
Direct road reefer loading is preferable for blackberry because every additional handling point costs drupelet integrity. Suppliers are normally BRCGS or IFS Food certified.