In a medium stainless steel saucepan, bring vinegar to a boil over high heat. Remove from heat and add mustard seeds.
Cover and let stand at room terperature until seeds have absorbed most of the moisture, about 1 1/2 hours.
In a blender or food processor fitted with a metal blade, combin marinated mustard seeds with liquid, water and Worcestershire sauce.
Process until blended and most seeds are well chopped. You want to retain a slightly grainy texture. Add cranberries and blend until chopped.
Transfer mixture to a saucepan and bring to a boil over medium heat, stirring constantly. Reduce heat to medium-low and boil gently stirring frequently, for 5 minutes. Whisk in sugar, dry mustard and allspice.
Continue to boil gently over low heat, until volume is reduced by a third, about 15 minutes.
Ladle hot mustard into hot jars leaving 1/4 inch headspace. Remove air, wipe rims.
Add hot lids/rings and process in a water bath canner for 10 minutes once the water has come back to a full boil.