Those muggy Boston summers inspired many cold soups with numbers. Another favorite was Cold Cucumber Soup III from The New York Times Natural Foods Cookbook, published originally in 1971. My paperback copy, the ninth printing, was probably purchased two or three years later.
There's not much evidence of strenuous use (scarcely stained--binding intact). I think I tried a number of recipes, in pursuit of wholesome, healthy eating (oh how ahead of the times we young lefty hippies were), but the only one that I repeated regularly was this cucumber soup. The recipe calls for chicken broth, and I always used homemade soup, but if I made it today, with the likely prospect of vegetarians in the house, I’d use a good vegetable broth.
Heat two tablespoons butter in a heavy skillet and add 1 onion, finely chopped 1 clove garlic, finely chopped, and 3 large cucumbers, peeled, halved lengthwise, seeded and chopped (I remember thinking it quite extraordinary to be cooking cucumbers for a cold soup--but as I say, this dish did win my heart). Cook about ten minutes.
Sprinkle with 3 tablespoons flour. When flour is cooked a bit, gradually stir in 4-6 cups good vegetable (or chicken) stock. You can play around with these amounts, depending on how big the cucumbers, how thick you want the soup, etc. Add 1 teaspoon salt and bring to a boil. Turn heat down, cover and simmer until cucumber is tender. You can then puree it with an immersion blender. (If using a regular blender, cool before blending in batches) Stir in 3/4 cup sour cream or yogurt, a few tablespoons fresh dill, and 1 teaspoon grated lemon rind. Chill.
Endless variations are possible. In the summer of 2011, when I once again find myself on the humid east coast, I remembered this soup. Sam is no longer a vegetarian so I could go with chicken broth--which is, I think, richer and more satisfying--or maybe just more familiar. The quantities of liquid in the original recipe seemed very meager--so I kept adding more--as now recommended above). In a complete abandonment of past procedure, I left out the sour cream, and served a bowl on the side to be added at will. The soup was rich and delicious enough without the added cream, though there were those who happily stirred in as much sour cream as they desired.