Pour 2 liters of water into a large saucepan. Add the lemon slices, onion slices, bay leaves, juniper berries, and carnations. Pour in the vinegar and white wine. Bring to a boil over medium-high heat, then reduce to medium and simmer for 15 minutes.
Gently add the carp to the simmering liquid. Reduce heat to low and poach for 30 minutes, keeping the liquid below a boil.