Locations: Nexus, Hyperion, Havarl, Kadara
After your initial introduction to the Vortex (the club in the Docking Area of the Nexus, reachable after establishing an outpost on Eos), talk to Anan at the bar.
She'll ask you to gather ingredients for Dutch's imbibable experiments. The first batch, according to the quest log, is the Atrium of the Habitation area aboard the Hyperion, but really it's just outside.
Scanning the hops is as good as picking them up, apparently. Return to the bar for some XP and drink called the Tall Moose.
When you gain access to the Angaran planet Havarl, follow the objective marker to a monolith southeast of the initial landing site (the same place you'll go to rescue the stasis'd scientists).
You'll have to clear some Remnant guardians, as per usual, though note that this is one of the first places in the game you can encounter a Nullifier.
When the bots are dead, scan this one very particular mushroom to get the exotic alien hops Dutch needs for his next concoction.
Drop it off at the Vortex next time you're by. Note: if Dutch serves you a Lucky Leprechaun in return, think very carefully before accepting.
Equip this quest on Kadara to note that the marker is right next to one of your Forward Stations, due west of the city. Scout this area (keeping a ware eye out for roaming raiders), and discover an odd black flower in the flats here.
Scan it and return to Vortex when ready. And that's it. No big finish, no special reward or alcohol related perk; the barkeepers will barely even remember who you are. Yay.