I cover mine in salt overnight. The next day I gently warm up chosen vinegar, and I use alsorts for different tastes - balsamic is great, so is cider vinegar, add whatever spices I fancy, along with some sugar and a few dried chillis, then once the sugar has dissolved I leave the vinegar to one side to go cold. Rinse and dry the shallots, pack into sterile jars tightly and cover completely with the vinegar and spice mix. Seal, label and store in a cool dark place. We open ours after a month as we don't like them to vinegary. I don't like vinegar in it's raw state, can only take it in home made chutneys and home made pickles. I have my first jar ready and have shallots drying, hoping they will store until the end of October so I can make a jar or 3 for Christmas.