Mix the vinegar and water with milk agitation. Dry blend the starch with 0.5 of the sugar and add to vinegar solution; mix and allow to hydrate under mild stirring. Dry blend the Methocel gum with the remaining sugar and other dry ingedients (salt, mustard). Add to vinegar solution. Mix and allow to hydrate for 15 min under mild stirring. (Note: Methocel product is approximately 90% dissolved after 5 min.) Disperse the egg yolks and add the oil last. Homogenize.