What is the term for material lost when a batch is transferred from one vessel to another?
Not sure what the name is for the actual material lost, but the word for the allowance made for such anticipated waste/spillage is tret
http://www.thefreedictionary.com/tret
Residue is a term for the material left behind when cooking or preparing batches of chemical mixtures. (Yield describes the actual amount produced after residual and other losses.)