How i make conusmption to raw material = 0 to purchased item

Hi guys i want to set consumption to raw material in my company to 0
how i set consumption to 0 to specified raw material
Example
I purchasing aggregate with 200000 and details quantity 2000 kg and unit price is 100
I make consumption to 800 kg but details of these 800kg is more than one transaction
Now i want to make consumption =0 how i make that