What would your preference be, to pickle onions in clear distilled vinegar or dark malt vinegar? My gut feeling is to go with malt as I feel pickled onions should be in a dark jar. Is there any benefit to pickling in either vinegar type in terms of taste?
I much prefer malt vinegar for onions, I think it has a stronger flavour that complements the onions well. White vinegar is fine for more delicately flavoured vegetables such as cauliflower and cucumber
The dark pickling vinegar seems to always have a load of sediment in which I don't like, so I always use the clear stuff but top it up with a glug of balsamic. This gives you the dark colour but without any cloudiness, and tastes great too.
I always use malt vinegar option and chuck in lots of pickling spices and a number of dried chillis....I am a firm believer that more is best...and then add a bit more...!!