Put the cups of milk, condensed milk, cloves, cinnamon and blueberries in a medium pot.
Heat over medium-high heat, carefully, since milk rises easily. Once the milk is warm, take a bit and dissolve the coffee in it, put everything back in the pot, and keep heating and stirring occasionally.
When the milk comes to a boil, lower the heat to minimum and simmer for 5 minutes.
Strain the cola de mono with enough strength to mash the blueberries and leave the peel behind. Add aguardiente (to make it stronger, add a bit more and taste).
Bottle and keep refrigerated. It lasts for 10 to 12 days.
