In *Kingdom Come: Deliverance 2*, the side quest "In Vino Veritas" offers a delightful blend of intrigue and exploration, though it can be a bit complex with its multi-layered steps and a nested side quest. Let's break down how to navigate this quest effectively.

Speak with Casper and Havel

Your journey begins with Casper Rudolf, who you'll find tending to his drink cart on the east side of Kuttenberg City. Simply enter through the east gate and proceed straight ahead to meet him. Casper's curiosity about the secret behind the monks' superior wine sets the stage for your adventure. Engage thoroughly in dialogue to uncover information about Havel and a book he left with Adleta, which will shape your approach to impressing Havel.

If you choose to retrieve the book from Adleta, head to the southeast corner of Kuttenberg's inner wall during daylight hours. You'll find an open garden where Adleta spends her time. Before approaching, gather five Marigolds. Arrive before her brother Hugo, or gain his permission to speak with her. Be kind and mention you need the book for Casper. You can either pass a skill check to convince her or offer the Marigolds as a gesture of goodwill to obtain the book. Once in your possession, take a moment to read it from your inventory.

Alternatively, you can bypass the book retrieval and head directly to Havel at his inn in Kuttenberg City. Prepare by enhancing your drinking skills and dressing to boost your Charisma to at least 18. Engage Havel in conversation and select these options:

• Germany. Let’s do it.
• That’s a very fine gift.
• Steinberger.
• It’s missing ginger.

These choices will impress Havel, prompting him to reveal the monastery's secret ingredient. Return to Casper with this crucial information.

Find the Monastery’s Secret Ingredient

Next, make your way to the vineyard north of Kuttenberg. Initiate the "Under the Straw Hat" side quest by speaking with the recruiter, which allows you to roam the vineyard freely without being considered a trespasser. Inside, locate Jerome, typically found on a bench near the main building.

Sneak into the main building, turn left towards the storeroom, and use your lockpicking skills to access the chests within. Inside, you'll find the Sulphur Wicks that Casper needs. For additional rewards, visit the garden behind the main building and collect five seedlings before you depart.

If you wish to complete "Under the Straw Hat," participate in vineyard tasks such as removing plants and moving sacks. After contributing enough, report back to Jerome to receive some Groschen as a reward. Otherwise, return to Casper with the Sulphur Wicks and, if you've gathered them, the seedlings.

With that, you've successfully completed "In Vino Veritas" in *Kingdom Come: Deliverance 2*. Now, you're free to pursue other quests or perhaps indulge in collecting badges and dice for a change of pace.