Author's Note

for those wondering what the main character here looks like:

Chapter 1: Unequal measure

Boiling is such a mundane task, but distilling is considered advanced and even fancy. A single drop of condensed fluid clinging to a pot’s lid carries less wonder than a colorful red fluid running down a long glass tube and into a cooling spiral. There's something mesmerizing about it. Probably movement and color, but both together create a sense of elegance that is only surpassed by said drop falling into a flask or beaker to change the color of its contents in a dazzling instant switch.

Scenes like this were why Brewberry loved potion making. Obviously his cutie mark contributed to said affection, but the white stallion with purple eyes and purple mane that flowed in ways not dissimilar to a fluid when you squinted was certain that even if it wasn't his talent, he’d still adore the process.

Flights of fancy like this usually were easily spotted. Brewberry had a tendency to stare off into the middle distance when he mused about these things. His teacher knew this and tended to pull the stallion back with a soft slap to the back of the head. More gesture of friendly mocking than violence on a student.

Brewberry jolted back to reality and fixed his eye back on his teacher, a deer named Barksmee. Barksmee was quite old, but also one of the best potion makers in all of Equestria even by deer standards. This old deer with graying fur was exactly why Brewberry had travelled here into the deer capital all the way in the heart of the Everfree Forest. Initially after he had discovered his affinity for potions he had traveled to nearby Ponyville as a colt to study under the wise Zecora, living at his aunt Berry Punch’s house until he had learned all the wise zebra could teach. On his 17th birthday, he had headed deep into the forest to seek out the undeniably best teachers of the arts of alchemy. At first the deer had been suspicious but a demonstration of his skill quickly earned him the mentorship of Barksmee.

“Eyes on the prize, Brewberry,” scolded Barksmee.

“Oh yeah right, sorry,” he said with a nervous chuckle.

He knew this was a crucial step, so he refocused on the now green fluid in the flask he had just made. He had practiced this potion a lot, one of the hardest known to both pony and deer alike. Its effect was simple but its creation incredibly complex. It was a shrinking potion and Brewberry was about to finish. He knew it was pretty important to actually nail it this time since one of the core ingredients had run out and he wasn't keen on delaying this final test by having to go and fetch more.

“Alright keep your hooves steady, sprinkle in the pulverized bittershroom, not too fast, not too slow.” instructed Barksmee from behind.

Brewberry could practically feel his mentor’s piercing green eyes as he sprinkled in the finely crushed mushroom powder. The grains of the purple powder seemed to fall painfully slowly. The fluid changed color again now to a bright pink. He carefully lifted the final and most essential ingredient from its container. A small flask of water from the Neighagra Falls. This was what he was most concerned about. This water was fairly potent and the supply he had brought with him had been reduced to only this vial over the 6 years with the deer. He knew this water was finicky, prone to flowing faster than you'd expect. A surefire way to mess up dosage. However, one fact gave him a sense of security: he had tracked how much he had used of this last vial. He knew 3 drops were needed and he knew there must be 3 drops left in the vial. So instead of the usual slow pipette work, he tilted the vial directly into the beaker.
As he did, things seemed to happen all at once. Firstly, he could hear Barksmee yelling

“What are you doing?!”

Secondly, as the drops fell he realized it was more than 3 drops that were falling towards his potion. And finally, there was the blast. The solution evaporated the moment the 4th drop of water hit it. The newly green liquid immediately turned into a geyser of putrid smoke. It shot out of the top of the flask and began filling the room as the reaction in the beaker expanded the liquid to millions of times its own volume in an incredibly fine smoke that filled Barksmee’s laboratory faster than both of them could hold their breath.