With all the recent focus on fermented foods it is all too easy to ignore the oldest of these: vinegar. It is my favourite fermented foodstuff, which I naturally gravitate towards using to add a sour note to savoury dishes. It was only after giving it some thought that I realised the reason: all great dishes contain a balance between sweet, salty, fragrant and sour – with the added magical note of umami. The latter is of course enhanced when the right balance is struck.
Anna-Karien's Books, Cooks and Curiosities 