It takes up to three years for the soybean mix to produce oil. [Photo by Jiang Wanjuan/chinadaily.com.cn]

The factory has been through many ups and downs in the past, amid market pressure, he said.

"The nature of our production means we are high in cost and low in quantity, so our marketing cost is much higher compared to other businesses" he said, "I had the idea to give it up about six years ago, but somehow I persuaded myself that good things never come easy, just like our soy sauce."