I have canned butter using this 
method,(http://simplicityfirst.wordpress.com/2008/04/24/canning-butter/#comments),,however
 I was warned about the possibility of botulism..
  I understand it is near impossible to detect before ingesting.Any 'silver' 
method to insure my canning methods or
preventing it in the 'cooking' process ?? I believe Brooks has
discussed treatment somewhere,,but I am still waiting for my
collection on CD from W.( hint)
tanks in advance..
aka Jhon