You'll need 12 tablespoons of white mustard seeds to prepare your mustard. Place these in a jar, cover them with boiled water, and let them sit overnight. The next day, drain the seeds and grind ...

Store mustard seeds in a cool, dark location away from direct sunlight, such as a pantry or cupboard. Use airtight containers, such as glass jars or sealed plastic bags, to prevent moisture and ...

(The mustard seeds will soften and soak up most of the beer.) Sterilise the jars for the mustard. Wash in very hot water or on the hot cycle of a dishwasher. Preheat the oven to 160C/325F/Gas 3.