Whisk in 1/4 cup (60ml) of the whey, vinegar, salt, allspice, and cloves. Continue blending until all the ingredients are evenly dispersed and the mixture is smooth.
Spoon the homemade ketchup into a glass jar, top with the remaining (28ml) whey, and cover with cheesecloth secured with a rubber band or string. Let sit undisturbed at room temperature out of direct sunlight, for 3 days.
After 3 days, uncover the ketchup and stir it throroughly. Cover with an airtight lid and transfer to the refrigerator for storage. You can use it immediately, or store it in the refrigerator for several months.