Grain Drying Cost Per Bushel: Complete Breakdown

Grain drying is the most expensive post-harvest operation on most farms. For corn harvested at 25% moisture and dried to 15%, the drying cost typically runs $0.25-$0.55 per bushel — and on a 500,000-bushel operation, that is $125,000 to $275,000 out of pocket every fall. Yet most farmers cannot tell you their actual cost per bushel within 30%. The cost hides in four places: fuel, electricity, labor, and the one almost everyone forgets — shrink.

The Four Cost Components

1. Fuel (Propane): The Dominant Cost

Propane is the primary fuel for grain drying in the Corn Belt and across most of the US. Natural gas is cheaper where available, but the majority of on-farm dryers burn propane (LP gas). The cost per bushel for fuel depends on three variables: initial moisture, target moisture, and propane price.

The rule of thumb: 0.015-0.020 gallons of propane per bushel per point of moisture removed for a well-tuned high-temperature dryer. Older or poorly maintained dryers can use 25-40% more fuel. A dryer with dirty burner screens, worn fan belts, or incorrect plenum temperature will cost you $0.03-$0.08 more per bushel than necessary.

2. Electricity: The Overlooked Cost

Every grain dryer uses significant electrical power to run fans, augers, and controls. A typical continuous-flow dryer with a 30-40 HP fan motor draws 25-35 kW while operating. Over a drying season:

• High-temp dryer (continuous flow): 0.8-1.5 kWh per bushel dried
• Batch dryer: 0.5-1.0 kWh per bushel dried
• Natural air (bin drying): 1.2-2.5 kWh per bushel dried (long fan runtime)

At $0.12-$0.15 per kWh (typical rural electric rate), electricity adds$0.06-$0.22 per bushel depending on the drying method. Natural air drying uses less fuel but more electricity because the fans run for days or weeks instead of hours.

3. Labor: More Than You Think

Grain drying requires constant monitoring — checking moisture, adjusting temperature, managing grain flow, monitoring for hot spots, and handling any mechanical issues. During peak harvest, drying operations can run 16-24 hours a day for 2-4 weeks.

• Operator labor: 0.5-1.5 hours per 1,000 bushels dried (high-temp continuous flow)
• At $20-$30/hour: $0.01-$0.05 per bushel
• For natural air drying: Less intensive per hour but extends over weeks — total labor may be similar

Labor is the smallest direct cost component, but it has a huge indirect cost: if the operator is managing the dryer, they are not in the combine. Delayed harvest due to drying bottlenecks can cost far more in field losses than the drying itself.

4. Shrink: The Hidden Killer

Shrink is the reduction in sellable bushels caused by moisture removal and handling losses. It is the single most misunderstood cost in grain drying because it does not show up on any invoice — but it absolutely shows up on your bottom line.

Shrink has two components:

Moisture Shrink (Weight Loss)

When you remove moisture from grain, you remove weight. A bushel of corn at 25% moisture weighs more than a bushel at 15%. The formula:

Moisture shrink (%) = (Initial moisture - Final moisture) / (100 - Final moisture) x 100

For corn dried from 25% to 15%: (25-15) / (100-15) x 100 = 11.76% shrink. At $4.50/bushel corn price, that 11.76% moisture shrink equals $0.53 per original wet bushel.

Handling Shrink (Mechanical Loss)

Every time grain moves through an auger, conveyor, or elevator leg, some is lost to dust, cracking, and spillage. High-temperature drying also causes stress cracks that increase breakage during handling. Typical handling shrink: 0.3-0.5% per handling event. Over the full drying cycle (bin to dryer to storage), handling shrink adds 0.5-1.5% — another $0.02-$0.07 per bushel.

Important: Moisture shrink is an inherent physical reality — you cannot avoid it. But many grain buyers apply a shrink factor that exceeds the actual physical loss. The standard commercial shrink factor is 1.4:1 (1.4% shrink per point of moisture), which is higher than the actual 1.18% per point. That difference is essentially a hidden margin for the buyer. Farmers who dry their own grain and sell at target moisture avoid this commercial shrink penalty entirely — which is one of the strongest economic arguments for on-farm drying.

Total Cost Per Bushel by Drying Method

Moisture shrink ($0.50-$0.55 per bushel for 10 points on corn) applies equally to all methods — it is a physical constant, not a cost you can manage away.

Crop-Specific Differences

Corn

Corn is the highest-volume dried grain in the US. Typical harvest moisture is 20-28% depending on variety and harvest timing. Target moisture: 15% for storage, 15.5% is common for immediate sale. Corn tolerates high drying temperatures (180-220°F plenum) without significant quality loss, making it well-suited to fast, high-temperature drying.

Soybeans

Soybeans are harvested at 13-16% moisture and sold at 13%. Drying requirements are typically modest — 1-3 points of moisture. However, soybeans are more sensitive to heat damage. Maximum recommended drying temperature is 130°F for seed and 140°F for commercial. Natural air drying is more commonly used for soybeans. Cost per bushel for soybean drying: $0.05-$0.15 for typical 2-point removal.

Wheat

Wheat harvest moisture ranges from 13-18%, with a target of 13.5% for storage. Wheat can be dried at moderate temperatures (140-160°F) but is prone to kernel cracking if dried too aggressively. Wheat drying costs less per bushel than corn because less moisture is typically removed: $0.08-$0.20 per bushel for 2-4 points of moisture removal.

Reducing Your Drying Cost

• Lock in propane early: Pre-season propane contracts (June-August) typically save $0.15-$0.35/gallon versus spot prices during harvest.
• Maintain your dryer: Clean burner screens, tight fan belts, and calibrated moisture sensors can reduce fuel consumption by 15-25%.
• Use combination drying: Dry corn to 18-19% with high-temperature, then finish with natural air in the bin. This captures 60-70% of the fuel savings of natural air while maintaining throughput.
• Monitor and adjust: Over-drying by even 0.5% wastes fuel and shrinks sellable bushels. A $500 inline moisture sensor pays for itself in one season.
• Harvest timing: Every day corn stands in the field after black layer, it loses 0.5-0.75 points of moisture naturally (in warm, dry weather). Delayed harvest can reduce drying costs — but increases field loss risk.

Use our grain drying cost calculator to estimate your exact cost per bushel based on your crop, initial moisture, drying method, fuel price, and electricity rate. See where your money is going and identify the biggest opportunities to reduce your drying costs.