Chenpi is dried and aged citrus peel, while fresh mandarin peel is used right after peeling. Their aroma and taste differ in clear ways.
Aroma
Chenpi: The aroma is mellow and layered, with a longer-lasting aged citrus note.
Fresh mandarin peel: The aroma is bright and straightforward, with a fresher fruit scent but less depth.
Taste
Chenpi: A balanced mix of mild bitterness, spice-like warmth, and sweetness, with more rounded aftertaste after aging.
Fresh mandarin peel: More bitter and astringent, with a simpler flavor and a touch of rawness.
Overall, the choice depends on the desired flavor profile in dishes or drinks.