Inexpensive and High-Quality Plant Oils

Lunch included some unique pastries, and Aunt Li placed a full plate in front of Beibei, giving each person a piece. "Miss Bei, this is the radish powder cake you love. It was pickled in a clay jar buried in the ground before the New Year. Now the radish seeds are dried, and you'll have to wait for them to grow again, which will take a season. So, please eat more from this plate. Although it lacks the radish's fragrant aroma that you love, the sweet and soft taste is still there."

"Aunt Li, are you saying the vegetable seeds in the ground have dried up? How many radishes have we harvested from our own cultivation?" Beibei recalled the mature crops in the terraced fields outside the village, realizing she had overlooked an important question. Those were not unharvested rice grains but probably radish sprouts left behind, flowering and seeding, naturally replenishing, and Mrs. Zhang's next response confirmed Beibei's speculation.

"Oh, we've never harvested them. However, this year, we got some red and sweet turnips from Nanyang. People don't like these small and spicy white radishes, so the sprouts in the eastern fields have aged and produced seeds. I was thinking of leaving two plots for Miss to make new cakes and pulling out the rest to plant glutinous rice."

"Hulu Bu (胡芦菔) is the ancient name for carrots. It was brought in by the Huns through the Silk Road, so it carries the 'Hu' character, like Hu Ma (胡麻, sesame) and Hu Bing (胡饼, a kind of pastry). It's quite a 'Buddhist' way of survival, relying on natural seed falling for vegetable cultivation. In this manner, just growing radishes is something to be grateful for, let alone being small and spicy. Aunt Li, earlier, Jingjing asked you for some green oil. What kind of oil is that?"

"Jingjing said the ingredients you use for making 'Yi' (possibly a local specialty) are not good. Luckily, I had some leftover sesame oil and tea seed oil mixed together, preparing to make lamp oil, so I gave her some."

"How much tea seed oil do we have left?"

"We really don't have any left. Before the New Year, Biaozi saw wild animals digging tea seeds on the ground in the mountains, thinking it was something good to eat. He brought back a basket, and when he ground it with a stone mill, oil came out. It seems inedible, so they used that oil for lighting lamps."

"Now I understand," Beibei recalled reading an article online during her university days about the chapter on oils in 'Tiangong Kaiwu' ("天工开物"), a Ming dynasty encyclopedia. Before the Song and Yuan dynasties, people in the Tang dynasty didn't understand techniques like steaming, roasting, or refining oil. They only used a simple cold-press method. Oil tea took advantage of harvesting large fruits before the first frost, pressing a small amount of green oil for the use of nobility in skincare. Therefore, people of this era are likely in the early stages of exploring various plant oils and processing techniques. Beibei was quite excited about this primitive stage.

"Listen to me, everyone. We have something to do. As you all know, the fat we used for making 'Yi' earlier was from hunted animals, and the green oil we added is fragrant sesame oil. Actually, we can use other oils to make even better and clearer 'Yi.' That includes the tea seed oil and radish seed oil Aunt Li mentioned." Beibei clapped her hands to grab the attention of those at the table. "Radish seeds, like sesame seeds, can produce oil. However, they need to be roasted or steamed before pressing. For tea seeds in the mountains, we should look for small or pale-colored medium-sized fruits. The ones that crack open and turn black on the ground after the first frost have the best oil content. If we can find some seeds like that in the mountains, it would be great."

"Harvesting honey is best in the late afternoon. Now we still have two or three hours. How about we go and collect vegetable seeds first?"

Seeing the visibly excited and expectant expressions around the table, she continued, "After pressing the vegetable seeds for oil, we can not only make 'Yi,' but I can also make something even more delicious than Fuhai Tower. Mr. Qiao taught me a dish called 'Zha Tian Fulo' (炸天妇罗), I guarantee you've never tasted anything like it, and you'll love it so much your tongue will bite itself off." As it was now the transition from spring to summer, Beibei was concerned that the radish seeds in the ground might have burst open and fallen. It was essential to harvest them early, so she had to use the temptation of delicious food.

"Great! Let's go now, Jiawei. Let's hurry and call our fathers to join us." Surprisingly, the first to respond was the young Southern Inspector, but calling both Tong Father and Uncle Li suited Beibei's intentions, as they were both strong and capable workers.