In a slightly high-end room, in an inn that was introduced to them by the Adventurers Guild, Tor poured the white wine into Euphie and Mailey’s cups.
“Cheers.”
They clinked their wine glasses together and took a sip. Just like the one he had drunk in Durande, it had a flowery scent that tickled his nostrils before fading away. At the same time, there was a smooth sweetness and subtle sourness that stimulated the tongue just right.
Euphie held her glass against the light of a candle.
“It is delicious and easy to drink.”
“I like that it’s a little sweet.”
Mailey seemed to enjoy it as well, and her face broke into a smile.
Tor had bought some cheese to go with it, which he now stabbed with a small fork as he got to the subject at hand.
“Can you really make a carbonated drink so easily?”
If the twins said they were going to make it, then they must have a reason for believing they could. And while Tor understood that the things they bought today at the glass workshop and wine store were materials for it, he did not understand how it all worked.
Mailey wrapped some vegetables in slices of smoked cod as she began to speak.
“First, what is a carbonated drink?”
“In this case, it’s liquid with dissolved carbon dioxide.”
Tor had that much knowledge, at least.
The carbonated hot spring they had stopped by also contained dissolved carbon dioxide. While the content was not exactly the same as the drinks Tor was familiar with on earth, it was still carbonated water.
Mailey continued.
“In other words, you can make carbonated drinks by dissolving carbonic acid in liquid. But in this world, people do not even know what carbon dioxide is, so it is not something that anyone could just make.”
“Mr. Tor. Do you know how it was invented on earth?”
“No, I don’t know.”
When asked this by Euphie, Tor shook his head.
People often didn’t know the history of things, even though they were so close by.
And so Euphie told him what she had learned from their library of fallen items.
“The discovery and invention of carbonated water was the result of experiments by Joseph Priestly, an English scientist. While hanging a bucket of water over a brewing barrel of beer, he discovered that you could make carbonated water. This was because the beer yeast had broken down the maltose and turned it into glucose. Furthermore, as this change generates carbon dioxide, the density of the carbon dioxide inside the brewing barrel rose and dissolved into the water.”
“I see. Well, beer is also a carbonated drink.”
He had forgotten about that, since he was still a highschool student and did not drink alcohol back on earth. But the beer was indeed quite bubbly.
Now that he was satisfied with this, Tor’s eyes then moved to the ‘tartar’ crystals that Euphie and Mailey had bought.
“But that isn’t beer yeast, is it?”
“No, it is tartar. It is not a microorganism. But you understand that in order to make a carbonated drink, we need a source for the carbon dioxide?”
“…Ah, baking powder!”
Upon hearing her talk about a source, Tor finally and suddenly reached the answer, much to Euphie and Mailey’s surprise.
Baking powder was used when making bread, as it caused carbon dioxide to be released into the dough. It was mainly made of bicarbonate and weak acid.
As Tor knew about the acidity of wine, he realized that that was why they had bought the tartar.
“And I suppose the kelp ash is the bicarbonate?”
“Ye-yes, exactly.”
“Talking to someone who is born on earth makes things much simpler.”
“Though, I don’t know anything about the chemical formula.”
Mailey began to write the chemical formula on a sheet of paper while she explained it.
“As you said, Mr. Tor, the basics are the same as baking powder. But in this case, it might be more accurate to call it effervescent powder.”
“Effervescent powder?”
“It is a powder that existed from the Meiji era and was used to make carbonated drinks. Bicarbonate, in other words, the crystals that result from making sodium hydrogen carbonate and wine is mixed with potassium tartrate and sold as effervescent powder.”
Mailey said this much and picked up the cork from the wine bottle and showed the bottom-side to Tor. There was a small, semi-transparent crystal. So that was tartar.
“When the sodium hydrogen carbonate and tartaric acid react, they release carbon dioxide. Since we are prepared, allow us to demonstrate.”
“Uh, demonstrate?”
It seemed like they were going to start with some science experiments. Tor pulled back, as he never did like to study. But before he knew it, Euphie was standing next to him, and she then took his wine glass.
As he looked at her in surprise, she drank all of its contents.
“Hey, that was mine…”
“Now, let us begin.”
“So you’re just going to ignore me?”
The empty wine glass was placed in front of Tor.
Euphie then took out two different kinds of powder. One was white and the other was a reddish purple.
“The white one is kelp ash. The sodium carbonate that will replace the bicarbonate.”
Euphie sprinkled the white powder into the wine glass.
“And this red one is the tartar from the red wine barrels. The potassium hydrogen tartrate.”
The red powder was sprinkled into the wine glass as well.
And then Mailey brought over the bottle of white wine.
“And when I pour this in, there will be a reaction, and it will become a carbonated drink.”
Mailey tipped the bottle, and the white wine poured out in a gentle stream, mixing the powders within.
And then bubbles began to appear. The fine bubbles rose until they reached the rim of the glass.
“Here. The first sparkling wine in this world.”
“How very fancy.”
Tor chuckled, both with sarcasm and amusement at this demonstration. Still, he obliged the twins by picking up the cup and tasting the sparkling wine.
The refreshing sensation of bubbles bursting in his mouth. Every burst was like an explosion of aroma.
“Ohhh!”
He had been in this world for nine years. He had nearly forgotten what this was like, and so Tor could not help but raise his voice in surprise.
Yes, this was it. But at the same time, he realized that there was something strange.
“It is a little bitter?”
While the wine was on the sweet side, it wasn’t too distracting. But he did sense an odd bitterness as well.
It didn’t detract from the nostalgia that he felt, but it did seem like a shame, given how delicious the wine was.
The twins pulled their seats from the other side and placed them on each side of Tor as they sat down.
“Bitter? You must have a sensitive tongue.”
“What is that bitterness?”
“I suppose it must be from the kelp ash.”
Euphie said as she glanced at it.
Once he heard that, Tor’s mind immediately went to the times he had accidentally drank sea water.
“Is there anything that can be done about it?”
If this was a carbonated potion that healed wounds, then this bitterness would be nothing. It really wasn’t that bad.
But there was no harm in improving the taste. If the twins could do that, perhaps then they could collaborate with a tavern and offer this sparkling wine to cutomers.
Tor, Euphie and Mailey all smiled together.
“Mr. Tor. Are you aware of Sherlock Holmes?”
“He is a famous private detective from novels.”
“Yes, during Victorian England, which Sherlock Holmes is set in, there was a glass instrument called a gasogene, which allowed you to easily make carbonated drinks.”
When he heard ‘glass instrument,’ what came to his mind was the gourd-shaped glass bottle they had ordered at the glass workshop. So that was a gasogene.
Euphie showed him a rough sketch of the inner structure. The top and bottom were two separate spheres.
“The liquid that you want to carbonate is poured into the lower sphere, and in the upper sphere, you place your effervescent powder. And then you pour just a little water into the upper sphere and close the lid. The carbon dioxide that is then released will reach the lower sphere, where it will dissolve into the liquid. According to the principles of the gasogene, it should not be affected by the bitterness of the kelp ash.”
“You really thought this through, huh?”
“Yes. However, since we do not have the gasogene now, why don’t we just enjoy this slightly bitter sparkling wine?”
“A sparkling wine that only we know about.”
“Well, when you put it like that…”
They prepared enough for all three, and then they made a second toast before Mailey returned to the subject.
“Now, while we have succeeded in creating a carbonated drink, the real problem is the carbonated potions.”
“What is the problem? According to what you said, surely all you have to do is put the potion into the gasogene and dissolve the carbon dioxide, and then it is done?”
“Did potions exist on earth?”
“…I suppose it needs to be tested…”
As carbonated potions existed, they already knew that they were safe. However, as this was connected to an effect brought by magic, which modern science could not explain, there was no guarantee that there wouldn’t be side-effects.
For instance, it was possible that the potions substances might be changed after coming in contact with the kelp ash or tartar.
“And since we cannot afford to be injured during such tests, we will have to perform them on animals first. But how…”
Euphie and Mailey looked quite troubled at this. Tor was puzzled.
“Uh, surely that is simple enough?”
“Well, we could never use livestock. No one would allow that.”
“But there are plenty of creatures in the dungeon. And they are easy to capture.”
“…I didn’t think of that.”
“Yes, Mr. Tor would have no trouble capturing them alive.”
And so for the next few days, the mad trio of Adventurers were sighted, capturing monsters in the dungeon and feeding them potions.