Mana stands.
This was a concept Jin had been nurturing for a long time, but finding the right opportunity to introduce it had proven difficult.
In modern Japan, it would be comparable to the charging infrastructure for electric vehicles or hydrogen fuel stations. As long as there was little to no demand, the pace of adoption would remain sluggish. Jin believed that mana stands would only become truly relevant once the opportunities to use mana in the average household increased.
Mana was refined from ether, and that ether was supplied by the sun, Celane. Given the current rates of consumption, there was no fear of it ever running out. It was a resource one could rely on with total peace of mind. If anything, Jin worried that if this world chose to rely on fossil fuels like Earth had, the resulting environmental pollution would devastate the pristine nature of Ars.
A mana supply unit would be significantly—no, considerably—larger than a standard ether converter. Because its conversion efficiency was relatively poor, replenishing a storage device took a significant amount of time.
Jin’s plan was to downsize the technology slightly, improve the efficiency, and attach a metering device so mana could be sold for a fee. This would give rise to a new profession—the mana stand employee—thereby generating new jobs.
"...Hmm, that sounds interesting," Elsa said, nodding with an intrigued expression.
"I’m planning to discuss it with Reinhard at some point."
Among the members of the Jin Family, Reinhard possessed the keenest political mind; Jin felt he could provide excellent advice on the matter.
"So, the plan is to build a prototype mana stand first, while simultaneously reaching out to the Celuroa Kingdom and the Shouro Empire."
『My Lord, will you be using a Double?』
Laojun, who had been listening to Jin’s explanation, thoughtfully offered his assistance. Jin nodded.
"That’s the plan."
If possible, he also wanted to establish contact with the Kingdom of Elias, the Klein Kingdom, the Kingdom of Egerea, the Kingdom of Franz, and Mitsuho.
To hammer out the broad strokes of the policy, Jin entered a consultation with Laojun, Reiko, Elsa, and Taihaku.
＊ ＊ ＊
"Assuming we build the first unit for each country here, do you think we can leave the rest to the local magi craftsmen?"
『Yes, I believe that would be appropriate. However, there is one issue.』
"Hmm? What is it?"
『The meter.』
"Ah..."
To charge for the mana, they needed the price to be proportional to the volume dispensed. However, if the construction of the units was left to individual nations, the possibility of fraudulent meters arose.
"On the other hand, it doesn't feel right for us to manufacture every single unit ourselves."
"Jin-nii, what if the price was based on how long it took to fill the tanks?" Elsa suggested.
She argued that since time was a constant, there wouldn't be much room for significant discrepancy.
"Hmm. It might be harder to cheat than a meter, but they could still find ways... like intentionally slowing down the supply flow to pad the time."
If someone was determined to be dishonest, they would find a way.
"Ideally, we’d have a standard price for filling a mana tank of a specific size, but..."
Since mana tanks weren't standardized yet, that was currently impossible.
"Is it too much to ask for people to act in good faith?"
《Indeed. In fact, any plan that does not account for human malice is inherently flawed.》
Taihaku was biting in his assessment. Having served as the brain of a magifortress, such cynicism was perhaps only natural.
"...It doesn't look like we'll reach a conclusion on this right away, does it?"
"Yeah, probably not."
Elsa looked a bit drained.
"Jin-nii, in that case, why don't we shift focus and make that pressure cooker?"
"You're right."
Jin knew that when your thoughts hit a dead end, a breakthrough often came while focusing on something else. He judged that developing the pressure cooker was a necessary task anyway, so the time wouldn't be wasted.
"Alright. Elsa, Reiko, and I will get to work on the new pressure cooker. Laojun, Taihaku, could you two continue looking into the mana tank situation?"
『Understood.』
《As you command.》
With their tasks divided, Jin, Elsa, and Reiko moved from Jin’s workshop to Elsa’s. Edgar was already there waiting for them.
"Elsa-sama, Jin-sama, I have been expecting you."
Edgar explained that Laojun had already sent word. Jin felt a wave of gratitude for Laojun’s thoughtfulness; he had wanted to avoid acting as if he owned the place while in Elsa's workshop.
"...Jin-nii, about the pressure cooker. If we aren't sealing it with a physical lid, are we using... a barrier?"
"Yeah. I think a weak wind-attribute barrier should suffice."
The internal pressure of a typical pressure cooker was about 2 atmospheres, reaching 2.5 at the highest. The ones used on Hourai Island operated at 3 atmospheres or more—some even reaching 10—but those could only be used safely because the pots were made of adamantite and the gaskets were crafted from magical beast leather.
"...In that case, would this magi-sequence work?"
Elsa began sketching a magi-sequence mixed with magi-formulas onto a Ground Spider resin whiteboard used for brainstorming.
"Yeah, that looks perfect. You've really improved, Elsa."
"...Thank you."
At Jin’s praise, Elsa couldn't help but blush.
"N-now then," Jin stammered.
He wanted to say something more to the blushing Elsa, but since a clever remark didn't immediately come to mind, he settled for a rather disappointing pivot.
"Let’s decide on the material for the pot itself."
"If the barrier is maintaining the pressure, can we just use ordinary metal?"
"Yeah, I think so."
"In that case..."
The standard material for pots used by the general public was brass. However, brass had surprisingly—or rather, "considerably"—poor thermal conductivity. Jin wasn't entirely sure how much that would negatively impact cooking, though. After all, the stainless steel used on modern Earth had less than one-twentieth the thermal conductivity of copper, yet it was the standard for pots and kettles.
"Hmm..."
Copper cost between 1,800 to 2,700 tolls per kilogram, while iron was 5,000 to 7,000 tolls. This was largely due to the abundance of native copper in this world. Setting the raw cost aside, Jin was determined to use stainless steel for these pots.
Copper-based cookware oxidized quickly, turning black and requiring constant polishing. Among the commoners, there was even a saying that a wife’s character could be judged by the shine of her pots. It wasn't just about debunking that superstition; Jin simply preferred stainless steel for kitchenware because it was resistant to acids and alkalis and didn't rust easily, even if it was a bit more expensive.
"To bring the cost down, we’ll eventually have to increase the raw production volume."
But that wasn't something they could achieve overnight.
"Father, isn't it unavoidable for it to be a little expensive at first?" Reiko asked.
"Hmm, I suppose you're right."
『My Lord, it appears that iron ore is being mined in great abundance in the Mitsuho territory.』
If that was the case, it could become a major trade good. Since nickel and chromium weren't widely utilized yet, they were relatively cheaper than they had been on modern Earth. This gave Jin a viable path toward lowering the price of stainless steel.
"We have a lot on our plates, but for someone who considers craftsmanship their calling, it's incredibly rewarding."
All that remained was the integration with the barrier. The pot would be made of 18-8 stainless steel, with a magi-crystal mounted on the lid. The pressure would be set to 3 atmospheres.
"I want to try it out," Elsa said.
"Yeah, let's do it."
Without a moment's delay, Elsa prepared to test the prototype pressure cooker with some actual cooking.