Ethanol-Corn Crush Spread

The ethanol-corn crush spread is the difference between the revenues from selling ethanol and its co-products minus the cost of buying corn as feedstock. It measures the gross profit margin of dry-mill or wet-mill ethanol production, and serves as a real-time gauge of whether production is economically viable.

How the economics work

A bushel of corn (56 pounds) yields roughly 2.8 gallons of ethanol plus residual co-products—primarily distiller’s dried grains with solubles (DDGS) and corn oil. The crush spread calculation is straightforward: take the revenue side (ethanol sold at a set price plus the value of DDGS and corn oil), subtract the cost of the corn input, and you have the gross margin before labour, utilities, and maintenance.

For a dry-mill plant, the revenue side might look like 2.8 gallons × ethanol price + 17 pounds of DDGS × DDG price + recovered corn oil. If corn costs $4 per bushel and ethanol trades at $2.50/gallon with DDGS at $120 per ton, the spread widens or narrows depending on the co-product yield and market conditions. Traders monitor this spread because it governs whether producers run at full capacity or throttle back.

Why producers care

Ethanol facilities are capital-intensive. Once a plant is built, marginal operating decisions hinge on the crush spread. If the spread turns negative—meaning it costs more to buy corn than you can sell the refined products for—producers shut down or operate at minimal levels. If the spread is healthy, they run flat out and may even bid aggressively for corn to secure feedstock.

This is not purely a commodities question; it also reflects market-making dynamics. Banks and hedge funds trade the spread as an implied volatility play, because ethanol and DDGS prices correlate with crude oil and livestock feed demand respectively. A trader holding long corn and short ethanol is essentially betting the spread will narrow; the opposite position bets it will widen.

The co-product question

The crush spread is only as useful as the co-product forecast. DDGS—the protein-rich residue—is sold as livestock feed and competes with soybean meal and other proteins. Corn oil is extracted and sold as a biofuel feedstock or cooking ingredient. In years when livestock are scarce or soybean yields are high, DDGS prices collapse, dragging the crush spread down even if ethanol is firm. Conversely, tight soy markets lift DDGS prices and widen the spread dramatically.

Wet-mill producers, which extract corn oil and corn syrup as intermediate products, face different economics and more moving parts. Their crush spread is wider but also more complex to calculate, and fewer traders actively monitor it.

Market drivers

The spread moves on three independent axes: corn fundamentals (supply shocks, planting decisions), ethanol demand (fuel blend requirements, export demand, crude oil price tracking), and co-product demand (meat prices, soy crush margins, biofuel policy). U.S. federal renewable fuel mandates—which require a minimum volume of ethanol blended into gasoline—provide a floor on demand but not price.

During periods of tight global grain supply, corn prices spike faster than ethanol prices, crushing the spread. Conversely, when crude oil rallies and ethanol tracks it upward, the spread can approach multi-year highs. Traders sometimes refer to the spread as “showing the real cost of the mandate”—because without policy support, ethanol might not compete with gasoline at current production costs.

Trading the spread

Commodity traders implement crush-spread trades by buying corn futures and simultaneously selling ethanol and DDGS futures (or forwards). The Chicago Board of Trade (CBOT) quotes Ethanol futures (ticker: ZEU) against September and December corn (ZCU, ZCZ). DDGS contracts trade on the CBOT as well, though less actively than corn and ethanol.

A long crush trader bets that the spread will widen—that the ethanol and co-products will rally faster than corn, or that corn will decline relative to ethanol. A short crush trader wets the opposite: that corn will rally or ethanol will weaken. The spread is mean-reverting over medium timeframes but can remain dislocated for quarters if one input faces structural demand or supply disruption.

Limits and nuance

The crush spread assumes a single unit of production and doesn’t account for crush quality, production efficiency, or plant-specific yields. Two identical plants might report different crush results because of processing differences, maintenance downtime, or co-product grading. The market price for DDGS reflects average quality; individual sellers often report basis points of discount.

Transportation and storage costs are also omitted from the textbook spread—a significant expense for landlocked plants. Regional ethanol prices can diverge sharply from the central Illinois reference point where most trading occurs. The spread is a useful signal, not a precise forecast.

See also