Put the blanched almonds in a blender with 1/4 cup of the lemon juice. Puree until totally smooth, then add the bread and melon and puree again. You will most likely need to puree the melon in batches. After pureeing one batch, pour out all but one cup of the liquid and then add the next batch. Season well with salt and white pepper. If the soup needs more acid, add the remaining lemon juice. If the soup is too thick, you can add a little water, but if the melons are really ripe, this shouldn't be a problem. Serve slightly chilled. Garnish with toasted almonds, grapes, and a swirl of creme fraiche.
Recipe courtesy of Bay Wolf Restaurant Cookbook (10 Speed Press, 2001) by Michael Wild and Lauren Lyle