Howdy from a new member, RNF. I got my start in charcuterie about 3 years ago and have been hooked ever since. As explained on Len Poli's site, dry milk powder helps minimize shrinking and aids moisture retention but I think that's mostly in cooked sausages. If you do want to make a substitution, you could try soy protein concentrate...unless that's also an allergy concern...at the low end of the range suggested on Len's site. I've had good results with it but admit I've never used it in a dry-cured product.