- 1). Purchase lye and methanol from a chemical or laboratory supplier. Lye can often be purchased from soap-making companies as well. Be sure the lye is KOH (potassium hydroxide) that is at least 85% pure.
- 2). Scoop the lye into a plastic bag and measure its weight on the scale. The purity of the lye will dictate the amount required. If it is 99% pure, measure exactly 4.9 grams; if it is 92% pure (most common), measure 5.3 grams; if it is 90% pure, measure 5.5 grams; if it is 85% pure, measure 5.8 grams.
- 3). Measure 200 ml of methanol and use a funnel to pour the liquid into the white plastic container. Close the cap to the methanol source container because it evaporates quickly. Add the pre-measured lye to the container using another funnel. Screw the cap on the container and shake in a swirling motion to mix the lye and methanol. Be patient--it will take about 10 minutes for the lye to dissolve completely.
- 4). Pour one liter of clean vegetable oil into a pot and heat to 155 degrees Fahrenheit. Use a thermometer to check the temperature. Pour the warmed oil into the blender. Pour the methanol-lye mixture into the blender. Secure the blender's lid and blend the mixture on low speed for at least 30 minutes.
- 5). Pour the blended mixture into a clean two-liter bottle. Screw the cap tightly and allow the mixture to settle for 12 to 24 hours. A dark by-product, glycerine, will settle to the bottom of the bottle. The bio fuel will fill the majority of the bottle as the top layer of liquid. Carefully pour the top layer of biofuel into another clean bottle or glass jar. If any of the glycerine pours with the biofuel, you need to settle the liquid and separate again.
- 6). Test a fuel sample for quality by washing with water. Pour 150 ml of bio fuel into a glass jar and add 150 ml of water. Place the lid on the jar and shake the contents for 10 seconds. The fuel and water will combine. Place the jar on a counter to settle. The contents should settle within 30 minutes, and the result should be a cloudy layer of bio fuel on top of a milky layer of water. The line between the two substances should be distinct. If the liquid appears creamy or has a thick, white layer separating the fuel from the water, the fuel is not good and most likely contains too much lye. Start a new batch and measure carefully.
- 7). Wash the remaining bio fuel with water if the test results show a quality product. Prepare a two-liter plastic bottle for draining by puncturing the bottom of the bottle to make a small hole. Cover the hole with duct tape. Pour equal parts bio fuel and water into the bottle. Replace the cap and shake the contents for 10 seconds. Allow the contents to settle for 30 minutes. If your test batch separated as described, the full batch should also. Drain the water layer from the bottom of the bottle by removing the duct tape so the water can pour out. Replace the duct tape when all the water is removed.
- 8). Allow the bio fuel to settle until the fuel is clear. It will have a tinted color, but it will not be cloudy. This can take several days. When the liquid is clear, it is ready to use as fuel in your diesel-operated vehicles.
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