Soak the almonds in enough water to cover them. Let them soak for 30 minutes.
Break the bread into pieces and soak in a bit of water.
In the bowl of a blender place the almonds and the almond water, the garlic clove, the bread, the sherry vinegar and 1 tsp salt. Blend until smooth. Add more water depending on desired thickness (I added 1/2 cup).
With the blender running, drizzle the olive oil in a very slow stream to help it emulsify.
Chill in the refrigerator a minimum of 2 hours. Just before serving, taste the soup to adjust for seasoning (salt and/or vinegar).
Ladle into small bowls, place 2 grapes cut in half and drizzle with 3 or 4 drops of extra virgin olive oil.
Notes
Optional: boil the garlic clove for 1 minute (this will make its flavor less pungent)