Place raspberries in a large stainless steel or enamel saucepan. Add sugar, orange zest and orange juice. Combine. Bring to a full boil over high heat, mashing berries with a potato masher as they heat. Boil until the mixture has thickened and the temperature reaches 220 degrees with a candy thermometer.

Ladle or funnel the raspberry jam into hot, sterilized jars, leaving 1/4 inch headspace.

Process for 10 minutes in a boiling water bath.