To be honest, she didn't expect him to know. After all, the people here did not know that saltpeter could make ice.
However, he had been reborn. If he knew this, it meant that someone in this world probably discovered that saltpeter could be used to make ice in the future.
As expected, he continued to hang up the mosquito net as he said in a low voice, "It was discovered a few years ahead, and later on, more people discovered it. As more and more people discovered it, it no longer became a secret."
"That's fine," Jiang Yue said. "I just want our house to be cooler in the summer." After a pause, she continued, "Things like rice noodles and liangpi are actually very simple. Although no one knows how to do it for the time being, someone will figure it out sooner or later."
As long as Sifu could seize the initiative and occupy the market first, even if someone found out later, it would not have a big impact on his business.