Display SKU on order post-confirmation?

I'm sure I'm just looking over the obvious, but I can't seem to find anywhere that allows me to add the SKU to the field list for the order form. Using the standard issue Commerce Kickstart V2 shopping cart, when the order is confirmed and email fired off, there is no sku on the line item. It would be very helpful to know exactly what those item sku's are considering the product line is in excess of 20,000 items. Any thoughts?