After extensive experimentation, I have developed an aged Manhattan recipe that I truly love.
This recipe makes 750ml - 1 liter of aged Manhattan cocktail, with a little bit of left over ingredients.
Shopping list:
1 bottle of either 4 roses yellow, small batch, or single barrel
1 french oak or cherry stave
1 375ml bottle of antica forumla sweet vermouth
1 bottle of angostura bitters
Directions:
1) Build a small fire and char the bottom 1/4 - 1/3 of the stave to a medium level (level #4 char). I recommend using tongs so you don't burn yourself.
2) Rinse the charred end of the stave off under the faucet with a brush for 30 seconds.
3) Mix the four roses with the antica forumla in a ratio of 2-2.5 : 1 to antica forumla vermouth.
4) Add roughly 8 hard dashes of bitters to the mix.
5) Place stave into the bottle that you want to use to age the cocktail. Either 750ml or 1liter bottles work.
6) Fill up the bottle with the mixed cocktail until the bottle is filled up all the way to the brim.
7) If you are using a french oak stave in 750: let it age 2 weeks and 2 days, then remove the stave. If you are using French in 1 liter, let it age closer to 3 weeks. If you are using a cherry stave, let it age at least 2 weeks in 750, 3 weeks in a Liter bottle, longer is ok too.
8) When serving, pour into a shaker glass or stirrer glass filled with ice. Smoothly stir for at least 30 seconds, strain into your favorite glass and enjoy!
(substitute Rittenhouse for a spicier mix, and cocchi vermouth di torino for an even lighter blend. As with all manhattans, the choice of bitters and garnish etc is up to you!)