I answered this question in the forum and thought it warranted saving, so here it is.

You have a unique problem concerning the loss of item qty when roasting.

What needs to happen is that the cost of the 150# needs to be transferred to the cost of 120#-roasted.  Not an easy one step thing to do in QB Pro.

I would create the two items as inventory items, coffee and coffee-roasted.  Then do your roasting.

Create a clearing expense account to use for this activity.  Bring up inventory adjust, set the adjustment to a value adjustment, set the adjusting account to the clearing expense account.  Lower the coffee from 150 to zero and click in another block so the math gets done.  Then look at the bottom right side and see what QB says the value is, find the coffee-roasted item increase the qty to 120 and the new total value to what you saw QB said the adjustment was.  Click save.

That takes the 150# and the value and moves it to the clearing expense account, then when you increase the coffee-roasted to 120 it take that same value out of the clearing expense account and assigns it to the coffee-roasted.

Sell the coffee-roasted item.