A day later, Ernest left the house earlier than usual.

But this time, he was not heading directly toward Hollen’s forge.

Instead, he carried a small cloth pouch tied securely around his waist containing part of the money he had saved during the past month.

And for the first time since reincarnating into this world, Ernest finally had enough funds to begin experimenting with something he had wanted since the very beginning.

Soap.

Real soap.

Not just washing with plain water like everyone else here.

As Ernest walked through the streets toward the market district, he could still remember how miserable his first bath in this world felt.

Cold water.

No shampoo.

No soap.

Just manually pouring water over himself using a wooden dipper while hoping the dirt somehow disappeared.

It did not.

The smell remained.

The grime remained.

People here simply accepted it as normal.

Which honestly made sense.

Proper soap production required knowledge and materials most commoners did not possess.

Back on Earth, soap was so cheap and common people barely even thought about it.

Meanwhile here?

It was closer to luxury.

Especially proper cleaning soap.

As Ernest entered the market district, the city was already alive with activity.

Vendors shouted loudly from their stalls.

Workers pushed carts loaded with vegetables and grain sacks.

The smell of livestock mixed with smoke from food stalls nearby.

And now that Ernest understood the city’s economy better after a month of working under Hollen, he viewed the market differently compared to before.

Before, it simply looked chaotic.

Now?

He could see supply chains.

Resource flow.

Material pricing.

Trade specialization.

Actually, markets themselves functioned like primitive economic networks.

Information traveled through prices.

Scarcity changed demand.

And every stall represented a tiny business operation.

Ernest slowed near one particular stall selling oils and cooking fats.

Perfect.

The merchant behind the counter looked middle-aged with thick arms and grease-stained clothing.

Animal fat.

Fish oil.

Rendered tallow.

Clay containers filled the shelves behind him.

"What do you need, boy?" the merchant asked.

Ernest looked around carefully first.

Back on Earth, soap production required several basic ingredients.

Fat or oil.

Alkaline substance.

Water.

Then heat and mixing.

Primitive soap existed for thousands of years already.

Even ancient civilizations produced rough forms of it.

The challenge was making usable soap consistently.

"I need rendered animal fat," Ernest said.

The merchant raised a brow slightly.

"For cooking?"

"Something like that."

The man shrugged before pointing toward several containers.

"Pig fat is cheaper. Beef tallow costs more."

Ernest mentally calculated immediately.

Cheaper first.

This was still an experiment.

"How much for pig fat?"

"I’ll give you about 100 riel for it."

"Good, I’ll take three."

He purchased several containers afterward before carefully storing them inside a cloth sack.

Next problem.

Alkali.

Modern soap production used sodium hydroxide directly for controlled industrial manufacturing.

But obviously, that did not exist here.

At least not commercially.

Primitive civilizations instead extracted alkaline solution from wood ash.

Especially hardwood ash.

When water filtered through ash repeatedly, it created crude lye water rich in potassium compounds.

Not perfect chemically.

But enough for basic soap production.

So Ernest headed deeper into the market toward the fuel and charcoal section.

The atmosphere changed immediately.

The air smelled heavier here.

Smoke.

Burned wood.

Charcoal dust.

Men unloaded firewood from carts while merchants weighed sacks using hanging balance scales.

Ernest approached an older vendor selling charcoal and bundles of hardwood ash collected from ovens and furnaces.

The merchant looked confused the moment Ernest asked his question.

"You sell ash?"

The old man blinked.

"...Ash?"

"Yes."

The merchant scratched his beard slightly.

"What for?"

Ernest could not exactly explain medieval chemistry casually without sounding insane.

"Cleaning," he answered simply.

That at least sounded believable enough.

People already used ash occasionally for rough cleaning purposes historically.

The merchant eventually shrugged.

"I usually throw most of it away."

Interesting.

Waste product.

Meaning cheap acquisition cost.

"How much?" Ernest asked.

The merchant waved dismissively.

"Fifty riels for an entire sack."

Honestly, Ernest nearly smiled hearing that.

From a production standpoint, low-cost raw materials dramatically improved profitability.

And if soap production worked properly, this could become far more than a personal hygiene project later.

He purchased one sack immediately afterward.

Now came another requirement.

Containers.

Soap-making required controlled mixing and heating.

Metal pots existed already, but Ernest needed something cheap enough for experimentation without angering Anna for ruining kitchen cookware.

Eventually he found a pottery stall selling crude clay containers and thick mixing bowls.

Back on Earth, modern industrial chemistry relied heavily on specialized equipment.

Temperature control.

Pressure regulation.

Stainless steel reactors.

Meanwhile here?

People solved problems using clay, iron, and fire.

Primitive.

But workable.

After purchasing several clay containers and a wooden stirring rod, Ernest finally stepped away from the market carrying his materials.

Pig fat.

Wood ash.

Clay mixing bowls.

Basic tools.

As he walked back through the streets, his mind already began mentally organizing the production process.

Step one.

Extract alkaline solution from ash.

Step two.

Heat rendered fat.

Step three.

Combine carefully while stirring continuously.

Then allow saponification to occur.

Simple in theory.

Difficult in practice.

Because soap chemistry depended heavily on proportions.

Too much fat and the soap became greasy.

Too much alkali and it became harsh enough to damage skin.

Primitive soapmakers historically learned through repeated experimentation rather than exact chemistry.

Thankfully, Ernest already understood the scientific principles behind the reactions.

The real issue was adapting modern understanding to medieval materials with inconsistent purity.

Still, even rough soap would already outperform plain water.

And if successful?

The implications went far beyond hygiene.

Cleaner workers meant reduced odor.

Potentially fewer skin infections.

Better sanitation overall.

Even productivity could improve indirectly.

It’s going to be exhilarating.