linda smith is a very well known lactation consultant. she lectures and holds lactation consultatant exam prep course on a yearly basis. people who have heard her speak say she's great- extremely knowledgable. anyways- she has a web site that has lots of great articles about breastfeeding. she also has alot of articles by jack newman md - another breastfeeding consultant guru. if you go to her web site, check out the article entitled "don't shake the milk". it explains how shaking breaks up the amino acid chains, leaving only pieces - thus ruining many of the beneficial properties of breast milk. the link to her site with that article is: http://www.bflrc.com/ljs/ls-arts.htm i only recently learned about the problems with shaking the milk. i used to "shake vigorously" to get the fortifer to dissolve. now i feel torn between maintaing cellular components or serving my babies a lumpy meal ! we don't charge for fortifier but i do know that it is very expensive. i wish someone would come up with a liquid additive! i've never heard of enfacare powder- what is it?