Based on my limited research most kashrus organizations say Raspberry's are not recommended, but I found this from the OU :
Raspberries
DESCRIPTION:
Considered by many the most intensely flavored member of the berry family, the raspberry is composed of many connecting drupelets (individual sections of fruit, each with its own seed) surrounding a central core. There are three main varieties — black, golden and red, the latter being the most widely available. Fresh raspberries are typically available from May through November.
INFESTATION:
Raspberries can be heavily infested with small mites and thrips. These insects can be nestled on the surface of the berry as well as inside the open cavity of the raspberry. Occasionally, small worms may be found in the cavity of the berry. Note that tiny, dark-colored, leaf-like or seed-like protrusions in the berry’s cavity may appear similar to insects, making the true insects difficult to discern.
INSPECTION:
Due to the very delicate nature of raspberries, they cannot be placed in water nor may they be extensively handled. Therefore, we recommend the following procedure as the most practical and effective way of checking raspberries:
1. Stretch a white cloth or sheet of white freezer paper over a light box or on a countertop with ample overhead lighting. Raspberries should be dropped one by one onto the white surface. This will dislodge at least some of the insects that may inhabit the berry.
2. If insects are found in a pint of berries, the pint might be infested and may not be used. There is no washing procedure that will guarantee removal of all of the insects.
3. If after dropping the berries no insects are found, the berries should be visually inspected one by one. Pay careful attention to the cavity of the berry where insects often hide.
The above article is based on the OU Guide for Checking Fruits, Vegetables, and Berries-2nd edition.
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