Layered, citrusy, lingering taste. Mandarinquat is the bigger, mellower cousin of kumquat, with milder, sweeter skin and a party-in-your-mouth tangy, juicy interior. This marmalade is made with rare mandarinquats that were tree-ripened and hand harvested from a private Napa garden. We used the whole fruit (sans seeds). Cooked in orange juice and a purée of ume plums added.