Combine mustard, flour, sugar, salt and turmeric in a small bowl.
Add water, a little at a time, mixing to make a smooth paste.
Heat vinegar and celery seed to boiling.
Add about 1/2 cup of hot vinegar to mustard mixture gradually.
Stir mustard mixture into boiling vinegar gradually.
Cook, stirring constantly, 5 minutes.
Add beans and bring to a boil.
Ladle into sterilized jars.
Store in refrigerator.