How to Make and Distinguish Sesame Oil?

Roast method of sesame oil
1. Screening. Remove the dust and impurity among the sesame with a fine sieve, and remove the light dust and immature seeds with dustpan.
2. Rinsing. Pour water into disk or cylinder, and put sesame into water and stir for 10-15 minutes. After removing the floating dregs, take the sesame out of water. Dry them using fine sieve.
3. Roast sesame seeds. Roast the clear sesame seeds inside the iron pan. At the beginning, due to the much moisture, you need the strong fire, and stir them evenly. When the steam disappears, change to the small fire. Until the sesame seeds kernel is maroon, add some cold water which accounting for 2%-2.5% of the total sesame seeds weight, roast and take sesame out of the pan.
4. Lift up sesame seeds and blow impurities away. Because the sesame seeds’ temperature is very high, even if you sprinkle a little water, the temperature would drop to about 150°C. But sesame seeds still need cooling down which is easy to make sesame charred affecting the quality of the sesame oil. Make the sesame seeds falling from a height, at the same time, blow from one side to cool down and blow away the impurities, so as to get the more pure sesame.

Tips:
Before pressing, you should roast sesame seeds until the seeds are brown and along with burst phenomenon. When roasting seeds, you’d better keep small fire at the beginning and at last, keep big fire in the middle. The pressing temperature is 140-150 ℃, and the moisture content is 1-1.2%.

Compare with sesame oil which is pressed using oil press machine and which is made by traditional method
About traditional technology: After roasting sesame seeds, use stone mill to ground sesame into thick liquid. Then soaked in hot water, through stirring and shaking, use the buoyancy of water to make sesame oil float out. It takes more time and more labor to use traditional technology to make sesame oil.

Distinguish the good from the bad
1. Water Identification: Use chopsticks to dip in a drop of sesame oil into the clear water, pure sesame oil will shows a colorless and transparent thin oil slick, and then cementesd a number of small oil droplets. Adulterated sesame oil slick is small and thick, and difficult to spread;
2. Color recognition: Pour sesame oil from the high place to the cylinder. If splashed oil slick is light yellow, it indicates that the rapeseed oil is mixed with sesame oil. The pure sesame oil is red copper color with very clarity and aromatous. Generally speaking, the color of pressed sesame oil is lighter than ground sesame oil.
3. Identification of freezing: Put sesame oil into refrigerator to freeze, take out and place it in the air for dissolving. Pure sesame oil overall would melt quickly, while poor quality sesame oil dissolves slowly. There will be a significant hard heart during the melted stage.
4. Heating recognition: Heat sesame oil in the pan, it will appear precipitate very soon. But if it becomes white which indicates that the oil is mixed with lard. If it becomes very clear, it indicates the oil is mixed with the rapeseed oil. If it becomes hair muddy, it indicates that the oil is mixed with the rice soup.
5. Odor identification: Take a little oil in the hands for friction, if the oil is along with pure flavor, it is sesame oil. If it is along with beans smell, the oil may be mixed with soybean oil. If the oil is along with spicy flavor, it may be mixed with rapeseed oil.
6. Shock method: Take a bottle of sesame oil to shake gently, if the bubble is transparent and disappears quickly, usually it indicates that  it is pure sesame oil. On the contrary, it is sesame oil of poor quality .
7. Taste Method: When you drink pure sesame oil, you will feel fragrant and sticky, and the taste is a little bitterness. Otherwise, it is sesame oil of poor quality .