Hi, I am not so sure about the physics store - because I received mine as a gift from a relative but I saw that RedMart has quite a number of options of different price range too. So I am not sure if u are looking for a particular brand of the red wine vinegar or just any brand will do. I think those tcm herb & goods store will also carry and make a better recommendation too yar
You can also try Hock Hua? My mum get a lot of stuff there. Otherwise the traditional market should have it.
Try Neighbourhood provision shops or Chinese medicine hall
Most provision shops or supermarkets will sell this.
I have contacts of someone who make and sell it
If its 红糟,Ustar supermarket
Ive seen it at redmart.. can try
Ntuc