Apple, nuts, and spices ground together and mixed with wine are symbolic of the mortar used by Hebrew slaves to build Egyptian structures. There are several variations in the recipe for charoset. The Mishna describes a mixture of fruits, nuts, and vinegar, for example. In order to enhance the symbolism of mortar, it is customary in some communities to mix in a small amount of sand. The charoset is sweet because sweetness is symbolic of God's kindness, which was able to make even slavery more bearable. According to legend, the use of apples in charoset stems from Pharaoh's decree that all male Hebrew children were to be killed at birth. Mothers would go out to the orchards to give birth, and thus save their babies (at least temporarily) from the Egyptian soldiers.
Apples and nuts can usually be found in the produce section.
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