We’ll have plenty more about the FDA gluten-free labeling rule that came out Friday. 

While I’m still digesting the 95 pages of the release, I wanted to point out something in the FDA’s update that echoed what was in my last entry.  In describing why the FDA chose 20 ppm as the level below which an item would be deemed "gluten-free", the FDA said,

This is the lowest level that can be consistently detected in foods using valid scientific analytical tools.

Well, exactly.  We can’t measure what we can’t measure.