Oh, I’m glad you said something before I accidentally got the food coloring stuff. I’ll see what Sunset Super and New May Wah have next week.
Some restaurant, is it MY China in SF?, serves their Xiao Long Bao with a red vinegar that I ignored. That would be a missed opportunity if it were Zhejiang vinegar and I didn’t bother to even try it.
If I can find the right vinegar, I’ll try her pickled ginger with both plain rice vinegar and red rice vinegar and do a blind taste test.
She uses red rice / rose vinegar in the following dishes (thank you, eatyourbooks.com) :
West Lake fish in vinegar sauce (Xi hu cu yu)
“Squirrel fish” in sweet-and-sour sauce (Song shu yu)
Shanghai soy-pickled radish (Jiang luo bo)
Shanghai pickled radish skin
Sweet-and-sour pickled ginger (Tang cu pao jiang)
Slow-cooked pork hock with rock sugar (Bing tang yuan ti)
Shaoxing “small stir-fry” (Shao xing xiao chao)
Shengjian Mantou sounds like a Christmas project, so you may have to wait a few months for a report 
