First, tear up the pieces of bread and soak them in a bowl with water for about 10 minutes.
In a food processor, blend almonds until they as are as fine as possible. You can also chose to blanch the almonds before hand and remove the skins, but it's not necessary.
Squeeze out the water from the bread and add that to the almonds in the food processor as well as the grapes, onion, garlic, chile, cucumbers, lemon zest and juice, salt and pepper, vinegar and a good drizzle of olive oil.
Start with 1/2 cup of water and blend until everything is incorporated. Add more water as necessary (I used about 1 cup) and adjust seasoning. More salt? More vinegar, etc.
When done, pour a ladle of soup through a fine mesh sieve over a large bowl and use a spatula or large spoon to push the soup through. Then take the solids and blend in the food processor again and continue to strain through a sieve, extracting as much liquid as possible.
Cover bowl with plastic wrap and chill in fridge for at least 2 hours. Garnish with lemon zest, cayenne and grapes and serve.