In the spring of Jiangnan, the rape blossoms are golden, attracting colorful butterflies and bees to fly among the flowers, and the rich floral fragrance is intoxicating. The fields and mountains are full of oceans of rape flowers. With the rise of sightseeing tourism, the rape flower is more famous, and people slowly forget its important economic value, squeezing oil.
The history of rapeseed oil pressing can be traced back to a thousand years, as early as the Northern Wei Jia Sixun's "Qi Min Zhi Shu", there are records of pressing oil. Since the Yuan Dynasty, which has accurate historical data to check, the old-fashioned wooden oil press has prevailed in China for more than 700 years, and with the progress of the times, the soil method wooden oil press has gradually disappeared due to less oil... But its fragrance and pure, the taste of my childhood, made me dream and drove me to look for rapeseed oil on the tip of my tongue.
Early summer in June is the best season for oil pressing. There are still many mechanized oil mills in the countryside, and you can smell the aroma of rapeseed oil from time to time. Driving all the way to look for it, often looking for incense, disappointed, the real indigenous wooden oil mills are very rare. Kung Fu did not live up to the painstaking people, and finally let me find it, Anqing City Tongcheng Old Plum Oil Mill. The adobe façade, the wooden frame, is old, but it does not lose its quaint atmosphere.
The oil mill was busy, but orderly, and the workers were all elderly. After harvesting rapeseed straw after 5 days of sun exposure, the pod shell becomes brittle, after threshing, black rapeseed is filtered down from the bamboo sieve, the color is dark and shiny, the particles are round and full, do not contain impurities, especially the dryness must be checked, the moisture content should be less than 11%, so that it is convenient to store and squeeze oil.
They are all familiar co-workers, each responsible for his own responsibilities. Screening is the first process, blowing away dust debris lighter than rapeseed through a windmill. Then use a coarse sieve to remove inclusions larger or smaller than rapeseed, respectively.
Grinding. The mill should be flattened, the grinding core should be adjusted, the unloading should be even, the large and small seeds should be ground separately, and the whole seed should not be produced when grinding; the milled seeds should be turned over and swept diligently.
After grinding the rapeseed, pour it into a large pot and steam. Steam the billet for about 2 minutes. The second blank is steamed for 25 minutes, and water is constantly added to the pot to replenish the loss. The steaming waist must not leak air, burn the fire and add coal evenly, and repeatedly copy until it is steamed through.
Wrap the cake, squeeze the head road to play double circles, two lanes to play single turns. Disperse the bread and concentrate on the press. Wrap the cake fast, and the cake should be stepped on flat. Bread is made of loose grass.
The blank is hidden, the ground rapeseed is fumigated by steam, the control of moisture and temperature is all based on experience, and whether the billet is pressed evenly or not directly affects the oil yield.
This is the Qi lao style, which is 65 years old this year, and it is the old style invited outside the oil mill. He controls the billet link, which is a major matter related to the amount of oil produced.
The vegetable cake blank should be compacted by hand, and many people repeatedly pressed it many times to narrow the gap as much as possible.
Loading is also a key task, or it must be personally fought by Elder Qi.
The placement of the cake and the control of the gap are very exquisite, which is also related to the oil yield.
Qi Lao's partner cooperated with him on the other side of the oil press. One load, one in the adjustment. At the rear of the oil press, it is embedded with square strips of wood, squeezed from the back to the front, and compacted one by one.
After all the installation, the final commissioning is done, and the oil pressing is about to begin.
Pressing is a heavy physical work, and it can be seen that this old man must have been a strong man when he was young. Pressing is also a complex process: light beating, frequent beating, so that the cake is quickly pressed; after the oil is lightly pressed, diligent pressure, after 1 hour, most of the oil is squeezed out; heavy beating, slow beating, increase the pressure. The impact bar should be flattened and evenly pointed up and down. After 3 hours of beating, 90% of the oil is squeezed out.
The golden vegetable oil gradually seeps out, diffusing a seductive fragrance.
The wood oil pressing process is complicated, consumes a lot of manpower, the cost of man-hours is high, and the oil production rate is lower than that of the machine, and the remuneration obtained is also less, so now all the machine is used to press oil, and wood oil is rare. When he was off work, Elder Qi chatted with me and said: This may be the last time he pressed oil, and he really can't move when he is older... I didn't know how to persuade him, so I asked him: Can you take an apprentice? He replied to me: In the early years, I brought a lot of it, but now none of them have done it... Alas, perhaps what the old ancestors left behind is really going to be lost.
Postscript: The second episode of "Heart Biography" of "China on the Tip of the Tongue 2" once showed the ancient method of oil pressing from Huizhou, and the picture taken was very exquisite and vivid, especially the section of tapping oil pressing was similar to a martial arts film, and a feast was prepared for the audience in the visual. However, after the program was broadcast, many netizens believed that it was easy to produce substances harmful to human health in the process of this oil pressing method, and the smoke point was too low during use. In fact, I personally think that this is a one-sided understanding. The mid-Qing Dynasty cookbook "Tuning Ding Ji" also has "Oil Theory": "Vegetable oil takes its thickness, sesame oil takes its fragrance, and it must be used both to make dishes." The hemp oil altar is buried in the ground for several days, and the oil and gas are removed before it can be used. Also, the sesame oil boils up the water vapor, that is, smokeless, and cold and available. Again, the small mill will be fried sesame burnt, the oil is fragrant, and the big car sesame oil is not as good as it is. Soybean oil, vegetable oil into the water boiled, known as 'cooked oil', to make dishes, do not damage the spleen and stomach, can be buried in the ground better. It is not difficult to see from this that the ancients have found a solution. Reality objectively speaks: the mustard oleosides and erucic acid of rapeseed oil are indeed harmful to human health, but at present, after variety improvement, many rapeseed oils used for oil pressing are now "double low" products. The ancient method of oil pressing is an expression of the inheritance of ancestral wisdom and is a tribute to the acquisition of delicacies through labor.