An acre of sunflowers yields about 800-1,500 lb of seed, which holds 280-675 lb of oil at 35-45% oil content, but a press recovers only 50-70% of that, so the pressed oil is about 140-472.5 lb, or 18-62 US gallons. Plant after the last frost 12-18 inches apart in full sun, harvest when the back of the head turns brown and the seeds are firm, dry the heads 1-2 weeks, and warm the crushed seed before pressing.
Part of Oil Pressing at Scale
Growing and processing sunflower for oil: climate range, planting and harvest, the yield per acre before and after pressing losses, and how the seed is prepared.
Sunflower Is The Default Because It Tolerates Almost Everywhere
The carrier rates sunflower the best all-around choice: it grows in USDA zones 2-11, is drought-tolerant and has high oil content, and the shells make mulch or fuel. It matures in 90-120 days, so it fits any season with that long between the last and first frost.
What The Acre Yields
The carrier’s figures are 800-1,500 lb of seed per acre at 35-45% oil, which it converts to 280-675 lb (35-85 gallons) of oil. That is the oil in the seed. Check the arithmetic and then apply the press:
- Oil in the seed: 800 x 0.35 = 280 lb and 1,500 x 0.45 = 675 lb. At 7.68 lb per US gallon (0.92 kg/L, assumed oil density) that is 280 / 7.68 = 36 and 675 / 7.68 = 88 gallons, close to the carrier’s 35-85.
- Pressed oil at 50-70% recovery (the corpus figure for simple presses; Seed Pressing): low case 800 x 0.35 x 0.50 = 140 lb, high case 1,500 x 0.45 x 0.70 = 472.5 lb, which is 140 / 7.68 = 18 and 472.5 / 7.68 = 62 gallons.
Plan with the pressed figure, 18-62 gallons per acre. The corpus’s chemistry page works from lower hand-worked seed yields and gets lower oil per hectare (Oilseed Crops); use whichever matches your own measured seed weight.
What You Need
- Seed of an oil variety (black oil types have the higher oil content), land in full sun
- Drying space for heads, and threshing by rubbing or beating
- A press and a crusher (Screw Press Design)
Method: From Field To Press
Step 1: Plant after the last frost, 12-18 inches apart, in full sun.
Step 2: Harvest when the back of the head turns brown and the seeds are firm.
Step 3: Cut the heads and dry them 1-2 weeks, then thresh by rubbing or beating the seeds out.
Step 4: Dry the seed to 8-10% moisture for pressing (Seed Cleaning and Drying).
Step 5: Dehull if you can: the carrier says hulls can be pressed with the seed but lower the yield and quality. Impact-beat and winnow, or crack the hulls in a grain mill set wide.
Step 6: Crush, warm and press. Sunflower needs heat pre-treatment for best extraction (Crushing and Heating).
Worked Example: Seed For A Barrel
To press 50 US gallons of oil (50 x 7.68 = 384 lb) from seed at 40% oil and 60% recovery, the seed needed is 384 / (0.40 x 0.60) = 1,600 lb. At 1,150 lb of seed per acre (the middle of the carrier’s range) that is 1,600 / 1,150 = 1.4 acres.
Common Mistakes
- Planning from the oil in the seed. The press takes only 50-70% of it.
- Pressing hulled and unhulled seed together. The yield and oil quality fall.
- Harvesting early. Cut heads only when the back has turned brown and the seeds are firm, as the carrier says.
Combustible dust and moving machinery
Sunflower hull and seed dust is combustible. Sweep it, keep open flame out of the processing area and never test for dust with a flame. The crusher and press have moving parts that crush; guard them and stop the machine before clearing a jam.
What’s Next
- Learn next: Seed Cleaning and Drying - preparing the seed
- Combine with: Oil Yield per Acre by Crop - sunflower against the others