Naem (or nem), also known as jin som in the northern Thai dialect (jin = meat, som = sour) is a common way of preserving pork meat In Thailand, it is mainly done in the northern and northeastern parts of the country – the land-locked regions
where a lot of pigs are pork features prominently in the local cuisines.
In the days before refrigeration, when a pig was slaughtered, there was usually too much meat to cook and eat up fresh in dishes like laab, soups, curries and stir-fries. The remaining meat would be chopped up and preserved with salt. Pork skin, also often too much to eat up by cooking fresh, was added to improve texture.