3. Inventories

The following table sets forth the components of the Company’s inventory balances (in thousands).

	March 31,		December 31,
	2017		2016
Raw materials
Corn	$	212	$	108
Enzymes and other inputs		217		309
Nutrients		14		10
Finished goods
Ethanol		190		72
Isobutanol		994		755
Jet Fuels, Isooctane and Isooctene		726		519
Distiller's grains		18		-
Work in process - Agri-Energy		245		274
Work in process - Gevo		161		62
Spare parts		1,401		1,349
Total inventories	$	4,178	$	3,458

Work in process inventory includes unfinished jet fuel, isooctane, isooctene and isobutanol inventory. During 2016, the Company chose to classify isobutanol as a component of finished goods due to the increased production of isobutanol at our Luverne Facility and the positive market development and customer demand for isobutanol being sold directly into the market as a gasoline blendstock.