Yes, nitrites do create a pink colour in the meat, and they do contribute a flavour, and they do help preserve the meat. But they are not necessary. You can get incredible colour and flavour by using just sea salt. Italian prosciuttos are made with sea salt only and are nothing if not rosy and delicious. I've done lots of cured sausages and a prosciutto with nothing but salt and a good basement--they were amazing, tasty as hell. I guess that depends on what you're making! It certainly isn't needed for its preservative effect in this day and age, but it does contribute its own distinctive flavour. Doesn't one of the pork/charcuterie suppliers mentioned in the Au Pied de Cochon cookbook have a stall at the Jean-Talon Market? (I'm thinking they're right next to the fishmonger in the new building.) They might be able to help you out. Alternatively, you could do what I did and order it from Stuffers.com. They have the benefit of being in Canada, so you don't have to deal with the border crossing. ← ←