Monkey blood tends to be red.
What other liquid is red?
It contains alcohol.
Red wine would work, if only you could find it.
This ship doesn't have a wine cellar.
It has a wine chest.
In a wine hold.
Have you visited the hold through the hatch in the floor on the sub-deck?
Open the chest at the front-right of the screen to get some fine red wine.
Now add it to your Monkey Island Mix.
Don't forget: the recipe asks for two doses of monkey blood.
And another dose to your Monkey Island Mix.