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.