Chapter Thirty-Seven: Twisted

At this time, distillers already existed.

The Tang dynasty revered Daoism, and the status of Daoist priests was exceptionally high. With the emperor's pursuit of immortality, alchemists who concocted elixirs were countless. Their alchemical pills were essentially small toxic pellets made of heavy metals, including mercury, which was obtained using a distiller.

The distiller used for producing mercury was a single-unit device, which easily carried impurities. For distilling spirits, such a single-unit apparatus was inadequate. The distiller and condenser needed to be separated, connected by a conduit, so that the hot vapor from the distiller could enter the condenser through the pipe, re-condense, and liquefy. This method minimized impurities and allowed the condenser to be reheated for secondary or even multiple distillations, extracting purer alcohol.

The structure of this split distiller was not complicated. Wei Renshi had used a small experimental model in his lectures to explain its structure to students in later generations—the design was essentially the same, merely scaled up.

The only difficulty lay in achieving the required airtightness of the distiller without rubber seals. Rubber rings were made of rubber, and at present, not only was there no rubber available, but even if one managed to obtain rubber from Southeast Asia, there was no way to manufacture rubber rings.

Thus, Wei Renshi considered several alternatives.

The first idea was to use wax to seal the joints. However, wax would melt under high temperatures, so this method was unworkable.

The second idea was to wrap a layer of cork around the inside edge of the distiller's joint. Once assembled, as the distiller's temperature rose, the cork would expand from heat and steam, making the joint tighter.

But upon reflection, wrapping cork around every joint inside the distiller posed great difficulty. Using fish glue to adhere it would result in the glue melting as distillation began, causing the cork layer to loosen and fall off, requiring reapplication each time—a tedious process.

Alternatively, nailing the cork in place would compromise airtightness. Furthermore, after the cork expanded from steam heat, opening the distiller would become difficult, potentially damaging the apparatus during expansion. If space was left in advance for cork expansion, initial airtightness would be affected.

So that wouldn't work either.

Wei Renshi furrowed his brow.

He could manufacture the distiller, only to be thwarted by such a minor issue at the joint.

Was there a way to ensure both ease of assembly and airtightness, without worrying about high-temperature steam?

He pondered for a long while but could not find a solution.

“Master, Young Master Li is here to see you,” Xier’s voice suddenly called from outside the door.

Wei Renshi went to open the door. Xier and Li He stood outside. Behind Li He was Li Rong, carrying a bamboo basket wrapped in cloth with something inside.

“If not for Brother Renshi’s help last time, Scholar Zhang would not have recognized my talent. In the future, when I encounter difficulties, I hope to seek advice from a renowned gentleman.” Li He said to Wei Renshi, “My mother asked me to bring this for Brother Renshi to try something new.”

“Why are you being so formal with me?” Wei Renshi laughed, giving him a gentle push.

“I said there was no need for formality, but my mother insisted we must express gratitude.” Li He turned to Li Rong, “Li Rong, hurry before it melts, go prepare it for Brother Renshi to taste.”

“Certainly!” Li Rong quickly headed to the kitchen, well familiar with the place. Xier, curious, followed.

“Melt… ice?” Wei Renshi was stunned. “Changji, where did you get ice? Does your family have an ice cellar?”

Li He shook his head. “My family is impoverished now; there’s no ice cellar. My twenty-eighth uncle brought a few blocks, along with some yellow sugar.”

Yellow sugar was cane sugar—since there was no method for purification at this time, it appeared amber-hued when made, hence the name.

“Twenty-eighth uncle? …Your father…” Wei Renshi was shocked—so many uncles!

“My father is ranked twenty-ninth,” Li He explained, “but most of those uncles have passed away; only the twenty-eighth uncle remains in Fuchang, and he can barely walk.”

As they spoke, Li Rong returned from the kitchen, carrying several bowls filled with pale yellow water tinged with amber, mixed with shards of ice floating within.

“Master Wei, please enjoy. I’ll bring some to the madam,” Li Rong handed over the bowls, then turned to leave.

“Ice water with yellow sugar—delicious!” Li He declared.

Wei Renshi drank his first cold beverage in Tang.

The yellow sugar carried a hint of cane aroma; icy sweetness flowed gently across his tongue, a refreshing coolness sinking to his heart and soul, indescribably delightful.

“Well?” Li He asked.

“I’m going to make ice!” Wei Renshi set down the bowl, speaking each word with solemn determination.

“Make ice?” Li He laughed. “Can ice really be made?”

“Of course, and it’s quite easy.” Wei Renshi’s imagination soared. “Once I make ice, I’ll make ice cream, shaved ice, popsicles, iced fruit juice, sparkling soda… just imagine!”

“I’ve had shaved ice, topped with crushed fruit—very cooling,” said Li He. “But what are ice cream and sparkling soda?”

“Ice cream is especially delicious. When I have ice and milk, I’ll make some for you to try,” Wei Renshi promised. “As for sparkling soda… I can’t make it. The water is fizzy, and when you twist the cap open, it sprays far; gulp down a few mouthfuls, burp, and it’s so satisfying… twist!”

Suddenly, Wei Renshi clapped his hands. “That’s it—twist! Threads!”

Li He was baffled. “Renshi, what’s the matter?”

“Changji, you came at just the right time!” Wei Renshi excitedly slapped Li He’s shoulder, laughing. “You’ve helped me out greatly!”

When he mentioned twisting off the bottle cap, inspiration struck Wei Renshi—he realized he could use threads to seal the distiller’s joints.

Though unscrewing would require a few turns, it wasn’t much trouble.

It would ensure airtightness, ease of operation, and eliminate worries about high-temperature steam deformation. The temperatures for distilling spirits wouldn’t deform the threads.

Wei Renshi was elated. “Changji, I must go to the study. In a few days, come again—I’ll make ice to thank you, and teach you how to always have ice at hand!”

With that, he rushed off to the study.

Li He stood outside, momentarily stunned, then smiled helplessly, muttering with curiosity, “Ice—can it really be made? Is it twisted out?”

He even mimed twisting in the air with his finger. “Can this really make ice?”