Manipulation of (the rate of) fermentation? That would be fascinating as hell to see. Go for it.
It's moe than just that, he can also control how strong it is from really weak to liver fail lol.
Ok nere it goesa

Name: Kyousei Takisake (loosley translated to Great Sake Waterfall XD)
Species: Hermit (nobody knows :derp:)
Title: The human with Oni's Scent
Age: Unknown, suggested to be very old.
Ability: The power to control alchohol (like potency and how long it takes to make it

)
Appearance: Apeears as a young male with brown hair and a slightly drunk look on his face, and blue eyes. wears and Edo era kamishimo set.
carries a giant gourd, probably filled with sake.
Personality: Although he looks drunk, he seems quite sober and easy to get attention of. but is easily angered like a drunk and can make your sake really strong without you looking :]
Storytime: Rumored to be the original creator of the Ibuki Gourd, Suika 'borrowed' it and never gave it back, so he made a bigger one for himself. He owns a bar in the center of the Human Village which is immensley popular and is visited by Humans and Youkai alike.
He is best friends with Yuugi, who always orders sake for him to bring to the former Hell.
People also take him very lightly, thinking of him as a very weak 'HUMAN', until they up getting extremley drunk by making his sake lethal to humans and some youkai, Oni only get knocked out by it.
No one knows where his origins are from, but udging by his outfit, he probably came from a long line of Edo era people and carried there traditions, which he didn't since he's from the Edo era...
He's known to be rough if rubbed the wrong way and could probably beat some lesser Youkai in battle.
Spells,
毒性のサイン、酒の空想的な霧 (Toxic Sign, Fantastic Mist of Sake): He takes his gourd and spills sake into the air and instantly makes it mix in with the air, making people drunk by inhaling it.
特別なヒョウタン、伊吹ヒョウタン (Special Gourd, Ibuki Gourd): Takes his own Ibuki Gourd and jams the top into the ground, which makes giant ruptures of sake burst from the ground.
フェスティバルサイン、100万Oni集会 (Festival Sign, Million Oni Gathering): He blows into his Ibuki Gourd which makes a very painful noise to humans and youkai but can attract Oni to help him in battle.
最終的なワーズ、不明瞭に発音された死 (Final Words, Slurred Death): This ability is quite brutal, he takes his Gourd and jams it into his opponet's throat and Suika comes to jump up and down on it, not know why she's doing this. He tries to get her off but only makes her angry and into a siisy fit and keep kicking the gourd into the opponents throat. At the end, the opponet had either died of choking or had been fatally drunk.
Relationships
Suika Ibuki (Theif, Customer)
Reimu Hakurei (Customer)
Marisa Kirisame (Customer)
Reisen U. Inaba (Customer)
Yuugi Hoshiguma (Friend, Customer)
Sakuya Izayoi (Customer)
Yukari Yakumo (Customer, Regular)
Win quotes
Reimu: ' Geez, after a few drinks the great Hakurei Maiden is downed...'
Marisa 'Hey! watch were your aiming that thing! your not that drunk!'
Suika: 'Give it back... now'
Sakuya: 'So you can make things happen instantly, I can only age good sake instantly... you make me jelous'
Remilia: 'Did you know your maid drinks?'
Flandre: 'Now I know why they don't give youngsters sake!'
Yuugi: 'Come on! you can take more than that! I know you can!'
Utsuho: 'Never seen you before, but Yuugi talks about you a little... do you like sake?
Suwako: 'Oh! a God? We should have a festival up here some time!'
Sanae: 'Good girls need to take it easy sometimes, pop down when your feeling overworked.'
Yukari: 'Wow your strong, but unfortunatley your drunk too...'
Yuka: 'Eep! *runs away*'
Reisen: 'Little bunnies can drink alot can't they? So have some more!'
yays done :]