Chapter 40: Refining Table Salt-Mataram minha mulher, me forçaram a me rebelar. Agora tenho cem mil soldados às portas da cidade!(Namorado de Yu Jimin)

Half an hour later, Qin Xuan arrived at the training grounds in the west of the city.

This area was vast, featuring not only a martial arts training field but also a horse-training facility, where the Divine Strategy Army conducted their daily cavalry drills.

However, he was not here to inspect the troops. Instead, he had the iron cauldron delivered to a large, makeshift workshop constructed behind the horse-training area. Inside, there was a newly built, massive stove, along with several objects that Zhao Luoying found rather bizarre.

"Your Highness, you ordered such a massive iron cauldron—surely you don't intend to use it for cooking rice?" Unable to fathom Qin Xuan's actions, Zhao Luoying could only make a wild guess.

Qin Xuan playfully tapped her dainty nose and chuckled, "This is for refining high-quality salt."

"High-quality salt?"

Zhao Luoying froze, her beautiful eyes widening in astonishment. She stared at Qin Xuan in disbelief and exclaimed excitedly, "Your Highness, can you truly refine high-quality salt?"

Two years ago, when they were still fighting on the border, Qin Xuan had mentioned some strange ideas to her. At the time, she had simply dismissed them as whimsical delusions. Qin Xuan, for his part, hadn't bothered to explain, as he had only brought them up in jest and had no time to put them into practice.

But now, with Beining City facing hunger and cold, if he didn't produce some real results, how could he save the thousands of people suffering in the crisis?

"The foreign tribes—the Jurchen, the Hangus, the Khitan, and others—do not truly lack grain; what they lack is salt and iron," Qin Xuan said, smiling at Zhao Luoying. "Beining City is currently under a blockade enforced jointly by the Jurchen and the Great Qi, cutting off our trade. But if we can provide high-quality salt and refined iron, do you think people from other nations would still heed the demands of the Great Qi or the Jurchen and refuse to trade with us?"

Zhao Luoying was stunned, her mind reeling. It took her a long time to steady her emotions. Ignoring the presence of their subordinates, she grabbed Qin Xuan’s hand and said softly, "Your Highness, then those things you told me about before—firearms that can pierce a willow leaf from a hundred paces, explosives that can split mountains, and fireworks that can fly into the sky and scatter light like stars—are those all real too?"

"Of course, and I will have them produced soon," Qin Xuan nodded with a smile.

With high-quality salt and refined iron as trade goods, he naturally needed to further enhance the defensive power of Beining City. Otherwise, disaster would surely befall them.

As they spoke, the soldiers and craftsmen placed the iron cauldron onto the earthen stove and lit the firewood.

"Your Highness, is it time to pour in the brine?" a man in his forties asked respectfully as he approached. He had once been an infantryman in the Divine Strategy Army, but after losing a leg during the defense of the city, Ning Yuanfeng had assigned him to oversee the salt refining process.

Qin Xuan nodded, and five or six craftsmen carried large wooden barrels, pouring the brine into the cauldron, bucket by bucket.

Zhao Luoying, not understanding the process, asked curiously, "Your Highness, why does this brine look so black?"

"This is the color of crude mineral salt after it has been crushed into fine particles, dissolved in clear water, and allowed to settle," Qin Xuan said, circling the iron cauldron and nodding slightly to himself.

Zhao Luoying knew what mineral salt was. Whether in the Great Qi or the Jurchen lands, it was the only kind available. Because it contained many impurities, it tasted bitter and astringent and even held toxic elements. Yet, even so, salt was a luxury usually enjoyed only by the nobility; ordinary people might not even taste it once a month.

"Your Highness, the brine is about to boil," the limping veteran reminded him.

"No rush. Control the heat well. We won't add the soy milk until we see crystals forming," Qin Xuan instructed, followed by a long wait.

Though curious, Zhao Luoying was afraid that asking too many questions might ruin his important work, so she waited anxiously and quietly. It wasn't until white crystals began to appear around the edges of the cauldron that she exclaimed in excitement, "Your Highness! Your Highness, there really are crystals appearing!"

Qin Xuan smiled slightly. This method of refining salt was known as the "brine-boiling method," which was no secret in the later ages. The reason for adding soy milk was that as the proteins formed into tofu curds, they would effectively absorb the impurities, accelerating the refining process. In this era, however, constrained by productivity and limited conditions, people had yet to discover or understand such principles.

"Yes, it is time to add the soy milk. Remember to use the bamboo ladles to scoop out the tofu curds that form," Qin Xuan said, feeling a touch of anticipation himself. Although he knew the theory, this was his first large-scale experiment.

The veteran nodded immediately and signaled three craftsmen, each standing at a different side of the cauldron, holding the prepared bamboo ladles. They used bamboo because the gaps in the weave acted as a filter.

After a flurry of activity, Zhao Luoying was delighted to see that the brine, which had looked so dark, was now becoming clear.

"Your Highness, how did this happen?" she asked.

Qin Xuan hesitated. He understood the chemistry, but explaining it in scientific terms would only confuse her further. He simply brushed it off: "The tofu curds absorb the pigments in the brine, so the water naturally becomes clear."

"Oh! And what happens next?" she pressed.

"Next, we continue to boil it until the remaining brine evaporates completely, and we will be left with salt frost," Qin Xuan explained, while silently keeping track of the time.

The key to the brine-boiling method was the temperature and timing; if the heat was too high, the refined salt would turn yellow.

As time passed, and more and more snow-white salt frost appeared, not only was Zhao Luoying thrilled, but Qin Xuan himself let out a long sigh of relief.

"Heavens! This method can actually produce such snowy, white salt?"

"This is nothing short of a miracle! Our Prince of Chu must be a celestial being reincarnated."

"I have never seen such a huge pot of high-quality salt in my entire life!"

At this moment, both the guarding soldiers and the working craftsmen were teary-eyed, looking on in utter disbelief. The salt frost before them was a miracle.

"Long live the Prince!"

The craftsmen knelt on the ground, kowtowing and shouting. To them, Qin Xuan was a god-like presence.

"Everyone, get up. Quickly use the bamboo ladles to scrape off the salt frost, then let it dry, and you will have true refined salt."

The newly refined salt frost still contained moisture and had to be dried. The craftsmen stood up and began to scrape off the salt with extreme caution, moving as if they were cradling infants, terrified of damaging even a single grain.

"Luoying, pass the order: from this moment on, this place must be heavily guarded. Furthermore, those responsible for producing the salt must be given separate living quarters and managed independently. The brine-boiling method must never be leaked."

With the experiment a success, Qin Xuan naturally had to make arrangements. Realizing the gravity of the situation, Zhao Luoying immediately ordered the entire workshop to be placed under tight security.