Of course, Shi Yiwen didn't know Song Qiyu's thoughts. At this time, he was concentrating on trying to make soap.

butter

Natural soda ash

Quicklime......

Although he studied medical school in college, he didn't leave behind his chemistry in high school, not to mention that he also helped his mother when he used waste oil to make handmade soap. He even went out of his way to help his mother search for relevant information on the Internet, at least in theory, he believed that he could make soap.

Although it is now done with the soil method, Shi Yiwen is also familiar with the road.

The clay jar is filled with water, and then the quicklime is thrown into the water, only to hear the sound of "swish", and when the lime reacts with the water, it immediately tumbles up, rising a burst of water mist.

"Quicklime reacts with water to produce calcium hydroxide solution, which is hydrated lime ......"

Talking to himself, Shi Yiwen slowly poured the soda ash into it again.

As soon as the soda ash was poured into the pottery jar, the water in the pottery jar instantly boiled as if it was boiling, and a large cloud of steam came out, and the whole kitchen was shrouded in steam for a while.

Looking at the turbid pottery jar, Shi Yiwen's eyes lit up and said.

"Hydrated lime is calcium hydroxide, which reacts with soda ash, that is, sodium carbonate, to form calcium carbonate, which is the friction agent used in the production of toothpaste......"

Shi Yiwen, who was talking to himself, nodded slightly, he really didn't expect that there was so much connection between toothpaste and soap production. After all, he just wanted to make sodium hydroxide in the first place. As for calcium carbonate, it was a completely unexpected harvest.

"That's fine, the two products complement each other."

Let the turbid clay jar sit for a while, and the calcium carbonate gradually sinks to the bottom of the clay jar, and the liquid floating on it is sodium hydroxide solution, that is, caustic soda.

After taking out the sodium hydroxide solution and putting it in a porcelain basin, and filtering it with a cotton cloth, Shi Yiwen poured the caustic soda into the iron pot on the stove.

When he was about to make a fire, looking at the fire sickle by the stove, Shi Yiwen was dumbfounded.

How does this stuff work?

Holding the fire sickle, he didn't know how to use it, so he had to shout outside the door.

"Little mercy, you come and help me raise the fire."

The young master actually can't start a fire?

Although she wanted to laugh in her heart, Xiao Lian still forced her smile and started a fire.

"Young master, this fire sickle is usually not used, take it, you see, it is usually used with fire folds, this is the ......"

Sitting in front of the stove, Xiao Lian smiled and took out a bamboo pipe under the stove.

"Fire Fold?"

In confusion, Shi Yiwen saw Xiao Lian pull out the lid of the bamboo pipe, and then blew lightly on the fire fold, and after repeating it several times, the fire fold burst into flames.

"Oh, I'm ...... Seen it. ”

Shi Yiwen, who originally wanted to say that he had seen the fire fold in the movie, laughed at himself when he saw Xiao Lian holding back a smile.

"I just didn't use it."

After leading the stove, when the caustic soda solution in the pot was heated, Shi Yiwen put the hard lump of butter into the pot one by one. As the butter melted, Shi Yiwen stirred it with a wooden stick from time to time. The alkali and the grease produce a saponification reaction at high temperature, the grease gradually disappears, and a layer of viscous liquid grows on the top layer of the iron pot.

"Young Master? Is that good? ”

Xiao Lian looked curiously at the yellowing goo in the pot.

"Not yet."

He took out some liquid and observed it, and found that there was still oil in it, so Shi Yiwen continued to add the caustic soda solution. This is repeated several times until the fat reacts with caustic soda and there is no longer any grease in the viscous.

These sticky, earthy yellow objects are soap.

If you just need soap, you'll be fine at this point.

However, because of the relationship between the manufacture of toothpaste, so Shi Yiwen also needs to extract the glycerin, the product of the saponification reaction is a mixture of sodium high-grade fatty acids, glycerin and water, the biggest feature of homemade handmade soap is rich in glycerin, which is a natural moisturizing ingredient. And industrial soap has an additional glycerin extraction process.

"Give me the salt."

Taking the salt from Xiao Lian's hand, Shi Yiwen sprinkled some salt in the viscous mixture. In order for the soap and glycerin to be fully separated, it is also necessary to continue heating and stirring.

While stirring, Shi Yiwen slowly added salt grains to the mixture, and the sodium of high-grade fatty acids was slowly precipitated from the mixed solution, and the process of adding salt to precipitate the soap was salting-out. Finally, after standing for a while, the solution is divided into two layers, the upper layer is the sodium of higher fatty acids, and the lower layer is a mixture of glycerol and salt. The lower solution is separated and purified to obtain glycerol.

However, further processing is needed to obtain crude glycerin, but because it is now mainly used to make soap, Shi Yiwen directly took out the upper layer of high-grade fatty acid sodium, which is "soap".

"Wouldn't that be too rough?"

Looking at the half-solidified soap in the soup basin, Shi Yiwen thought about it, and squeezed it into a square while it was half-solidified. Then it is poured out and placed on the ground to dry.

In the process of waiting for the shade to dry, Shi Yiwen was not idle, but directly took a small piece of thin soap flakes and came to the hall.

"I'm sorry, I've kept Ziyu waiting."

Song Qiyu, who had been waiting for more than an hour, said with a smile.

"It doesn't matter, it doesn't matter. Hey? ”

Seeing the dark yellow thing in Shi Yiwen's hand, he was curious.

"Brother Zhiyuan's hand is soap? How is it so small? Could it be that ten catties of butter are made like this? ”

"Of course not, everything else is frozen over there, and it's dry. I was afraid that Ziyu would be in a hurry, so I took a piece to try first. ”

Smiling, Shi Yiwen turned to Xiaoqing and asked.

"Where's the rag at home? Is it that oily, dirty rag? ”

After a while, Xiaoqing brought a rag, which was not dirty, but it was not clean.

"Young master, this, it's so dirty, can it be cleaned?"

Xiaoqing asked puzzled.

"You just have to wash it with this soap! It's sure to wash it off! ”

Shi Yiwen looked very confident, and even said it deliberately.

"Don't use a hammer to hammer clothes, the hammer will hurt your clothes, just rub it with your hands."

Listening to the young master's instructions, Xiaoqing began to use soap to wipe the tablecloth in her hands. While she was scrubbing, Song Qiyu also stood aside curiously.

Can it really be washed?

Under the gaze of everyone, as Xiaoqing scrubbed, a delicate foam appeared in the rag, the foam was white at first, then the foam turned black, and the water in the basin slowly changed color.

"Ah, why is this rag so dirty?"

Xiaoqing was surprised and continued to scrub vigorously.

In a few moments, the dirt on the tablecloth was washed away.

Really cleans up the dirt!

In everyone's surprise, Shi Yiwen said confidently.

"Little mercy, try another piece of washed clothes?"

Just as he guessed, he took a piece of clothes that seemed clean, washed them with soap, and rubbed them in the water, and sure enough, a lot of ashes were washed out.

"How? Ziyu, what do you think of this soap? ”

Looking at Song Qiyu, who was dumbfounded on the side, Shi Yiwen smiled.

"Can you sell it?"

"Yes, yes!"

nodded again and again, and then Song Qiyu looked at Shi Yiwen in surprise and said.

"Not only can it be sold, I dare to say, with this soap, within a year, Zhiyuan will be able to have a fortune!"