Since the pre-Qin Dynasty, sea salt has been prepared by cooking, and seawater has been evaporated by manual heating. This salt-making process consumes a lot of fuel, namely firewood.

However, when it comes to heating, there is another way to save firewood, which is to let the sea water bask in the sun. Compared with the salt cooking method, this is the salt drying method.

The method is also very simple, which is to introduce seawater into a large salt field composed of salt ponds. With the help of strong sun exposure, the seawater is evaporated and the remaining salt is finally obtained. This process does not require manual heating at all, so it can save a lot of costs.

Of course, Yuwen Wen knew the salt drying method, but he had never actually operated it. Therefore, after the novel salt making process was proposed, the reborn stove owners found ways to make it practical.

In short, two pools are dug on the tidal flats by the sea, and when the tide water level is high, the sea water is drawn into the first pool, and then after the sun is evaporated to a certain level, the pool water is introduced into the second pool to continue to dry.

At this time, the pool water (brown) is very salty. After being dried for a period of time, there will gradually be precipitated salt at the bottom of the pool.

It is indeed very simple, but the process is not that simple to formally carry out large-scale salt drying. However, this is not a problem for the stove owners. They may not be able to read at all, but they have accumulated rich experience in salt making when dealing with seawater for generations.

Because the debt is exempted and the family situation has been greatly improved, the enthusiasm of the stove owners to think about new processes has increased unprecedentedly. Several salt fields are thinking about the salt drying method at the same time, and they also exchange experiences with each other, so they quickly sorted out an effective salt drying process.

First, build a beach, and build a square beach pool at a certain size on the flat coastal tidal flats. The beach pool is dug from top to bottom step by step, and the drop is generally several inches. There is a pool door between the upper and lower pools to guide the pool water downward.

A platform is built in the bottom pool to store the precipitated sea salt, temporarily called the salt platform.

Large ditches on both sides or three sides are dug around the beach pool to prepare for tide storage and water storage, which is temporarily called salt ditch. A water door is opened on the ditches on the one side of the sea to set up a gate so that the switch can control the water flow.

A tide trench is opened outside, which leads directly to the sea to attract trench into the ditch and prepares salt ditch to absorb tides.

After the salt flat (pool) is completed, it is necessary to organize it. The soil in the pool is loose, dried, and then put it in the sea water to soak it thinly. Use your feet to step on the soil evenly in the pool, then use a scraper to level the bottom of the pool, then discharge the sea water in the pool, and use a stone mill to compact and flatten the bottom of the pool.

After the salt flat (pool) is ready, the tide can be absorbed. When the tide reaches the highest tide level, the sluice gate is opened to draw the sea water into the salt ditch, and then use the vertical axis windmill or manpower water wheel to introduce the sea water from the salt ditch to the highest level in the salt flat (pool).

After a day of drying, the seawater in the first level pool is introduced into the second level, and after a day of drying, the seawater is introduced into the third level, and at the same time, the seawater is drawn into the first level, and so on, using sun exposure to the seawater, so that the concentration of brine in the pool is increased step by step.

When the brine flows into the lowest salt platform, it is close to the maximum salt concentration. If it is dried for a while, the salt will be precipitated, which is "salt output".

Of course, the process of increasing the concentration of brine by step by step requires technical operation. It depends on people to judge whether the concentration reaches the level of "salt output", because when the brine flows into the last level of salt platform, insufficient concentration will lead to low salt output, and excessive concentration will also lead to low salt output.

This requires experience, but it is not a problem for the stove owners. In fact, except for the difference between human and non-human forces in the evaporation process, there is no difference in judging the concentration of brine.

Hundreds of years of experience in boiling salt have allowed the stove owners to know how to judge the concentration of brine. They divided the concentration of brine into ten percent, and ten percent brine is the brine with the largest concentration, which has met the conditions for salt production.

How to judge the concentration of brine? It’s not impossible to taste with your tongue, but there are too many disadvantages, so the stove owners have a method that is to use brine floats.

This is a special float, divided into two, one is "five percent float" and the other is "ten thousand float". If the five percent float rises in the brine, it means that the concentration of the brine is about 20 to 30%. If it floats flat on the brine surface, it is 50 percent brine.

If the tenth float floats float obliquely in the brine, it means that the water is 70 to 80% halogen. If the float floats flat on the brine surface, it means that the brine is 100% halogen and salt can be produced.

Yuwen Wen looked at the two floats in his hand, and thought of a modern device for measuring the salinity of seawater: a salinity hydrometer. Looking at the sincere-looking stoves in front of him, he couldn't help but feel a lot of emotion.

These stove owners are ignorant of the name, and it is impossible for them to know that the sea water has "salinity" and "specific gravity". They do not know that there are chloride salts such as sodium chloride and magnesium chloride in the sea water. However, they rely on generations of experience to make a very low-end brine float.

Without any theoretical basis, no scientific masterpiece, brine floats made purely by summarizing experience are actually the prototype of a hydrometer that can measure the salinity of seawater, and appear silently among the people.

Experience science, father and son passed on, and it ended abruptly in troubled times. Brine floats are still good. After all, the salt industry will not be cut off, but how many technologies that have sprouted from the people have disappeared in obscurity in the long river of history?

Seeing that Yuwen Wen was in a daze, Yang Ji was so angry that the others dared not show up. The scene was stalemate, so he coughed dryly, which made the other party come to his senses.

"Things are good, then what?"

"King, these are two kinds of salt, one is boiled salt, and the other is dried salt."

Two small plates each hold salt. One plate looks very white, it is boiled salt, and the other plate looks impure in color, which is dry salt.

Yuwen Wen tasted the salt in the plate separately. It was obvious that the salt was purified and basically had no miscellaneous flavors. The smell of salt was mixed with bitterness. Although it was not the same as yellow lotus, it could be felt.

"King, the salt drying method saves effort and firewood, but the coarse salt smells bad. If it is compared with boiled salt, I'm afraid that ordinary people will choose boiled salt if they have any choice."

Yuwen Wen nodded. He understood what the stove owners meant, and as a person who had received compulsory education, he also knew why this situation happened.

In addition to sodium chloride, there are also salt components such as magnesium chloride, calcium chloride, and potassium chloride in seawater. The reason why salt has a bitter taste is mainly because these magazines are at work.

How to eliminate this kind of impurity interference? He didn't know, and the stove owners knew it, but in the end he figured it out.

"King, the salt cooked in the same sea water is relatively salty and the salt produced is a bit bitter. After thinking about it for a few days, Caomin came up with a solution."

"That is to dissolve the coarse salt that has been dried with purified water, and cook it on fire. The refined salt obtained in this way tastes the same as the previous boiled salt."

Another dish of salt was served, and the color was white and the taste was obviously much better than the coarse salt that was exposed, and there was no difference between it and boiled salt. Yuwen Wen tasted it, but there was no bitter taste except salt. In terms of the purity of salt, it was slightly better than ordinary boiled salt.

When it comes to boiling, the salt produced by the secondary dissolution of the brine is higher than the salt produced by the natural brine on the mudflat. Therefore, if the coarse salt obtained by the salt drying method is not treated twice, its taste is not as good as the common boiled salt.

Not far away, there is a row of newly built houses, which are the place where coarse salt is processed. It uses a brand new iron pot, which saves firewood and has a roof to block the sun. The new stove has a good insulation effect. The salt cubes can no longer have to endure high temperature baking when cooking salt.
Chapter completed!