Remove seeds from peppers and chop in a food processor; set aside. Place in a large deep pan, the salt, sugar, mustard and vinegar Boil for 15 minutes; then mix flour and water in a bowl. Add to vinigar mixture in pan and stir Add peppers; cook until thick, about minutes. Put pepper butter in hot jars and seal, but not tight, Plac in waterbath for 5 to 10 minutes. Then retighten rings again. Makes 8 pints.