Along with tamari and sesame oil, I always use ume plum vinegar. No asian food store seems to carry it - and I'm wondering why not. It's the brine from umeboshi and only Eden brand seems to carry it. Did they stumble onto something good and Americanize this product that is not actually used in any Asian cuisine, or am I missing something? I get blank stares from Japanese storekeepers when I ask about it.