What they did was took a sample along with the batch numbers and sent it to the manufacturing plant. They compared the sample I gave them with a sample of the same batch they had a sample of and that's what they told me. Aparently they have samples of every batch they have ever made according to the tech guy. I have another meeting with the sales rep today and will post up what they say. I noticed the other day when you shake the bottles there is rock salt in the bottom. I have some new unopened bottles that have the same problem so that cancel out contamination. I have always been told nutes have a 12 month self life. I wish these companies would put dates on there bottles it would save a lot of head ache.