After my recent research into buttermilk, I got curious about
its cousins, yogurt and cr
ème fraîche.
After my recent research into buttermilk, I got curious about its cousins, yogurt and crème fraîche.
Most of us are familiar with yogurt. Commercial brands, in colorful 8-ounce tubs, usually line several linear yards of space in supermarket cold cases. They are flavored with everything from berries and bananas to vanilla, key lime and cappuccino, and contain various amounts of other elements such as stabilizers, artificial sweeteners and artificial color.
Crème fraîche, on the other hand, is not as commonly available in our supermarkets. Mainly found in France, it, too, is a fermented-milk product, somewhere between heavy cream and sour cream in texture and flavor. In cooking, it can be brought to the boiling point in a sauce without separating, as sour cream would.
Intrigued with the challenge of making my own yogurt and wishing for crème fraîche to eat with the season’s bounty of berries, I delved into my cookbooks and the Web for recipes.
The ingredients are simplicity itself: most homemade yogurt recipes use a couple of tablespoons of plain commercial yogurt as a starter. Crème fraîche recipes call for either commercial buttermilk or sour cream to start the fermentation. So far, no problem.
But every recipe I consulted also required that the mixture be kept at a temperature of between 90 and 100 degrees for 6 to 8 hours or overnight.
In the midwest or south, you could leave your project on a non-air conditioned porch and have it stay at that temperature. Or, if you have a gas oven with a pilot light, you could leave it there. But I needed another solution.
Handy husband to the rescue: he suggested I buy a styrofoam cooler and a 15 watt lightbulb (not a small appliance bulb, but one that would fit a regular socket). He already had a socket with a plug at the end; you could also find this at a hardware store.
He cut a hole in the lid of the cooler, screwed the bulb into the socket, and plugged it in. I put my instant read thermometer inside and found that the bulb was keeping the interior at about 120 degrees, too hot for my project. So he cut another 3-inch hole in the lid and attached a square of cardboard to it with a nail, so it could swivel open and shut. With this method we could keep the temperature at the required 90 to 100 degrees.
The cooler had been converted into a yogurt incubator. I proceeded to concoct the yogurt and crème fraîche.
Yogurt
(makes about 4 cups)
1 quart whole or 2 percent milk
2 Tbs. yogurt – look for one with active cultures. This is stated on the carton.
Step 1: In a heavy bottomed 4-quart saucepan, heat milk, stirring frequently over medium heat, to 185 degrees.
Step 2: Remove from heat and let cool to 110 degrees. The instant-read thermometer helps monitor this.
Step 3: Place yogurt in a medium bowl that will fit in your yogurt incubator and add a bit of the warm milk. Stir thoroughly, then gradually add the rest of the milk, about 1/2 cup at a time, stirring until smooth between additions.
Step 4: Cover the bowl with plastic wrap and place in the incubator for 6 to 8 hours or overnight.
Step 5: Place bowl in refrigherator until completely chilled.
Step 6: If you want the yogurt to be a bit thicker, you can remove the whey by placing a flat-bottom paper coffee filter in a strainer over a bowl. Gradually pour the yogurt into the filter and the whey will drain off. (Most methods call for cheesecloth, but this is not something I have on hand.)
Step 7: Reserve 1/4 cup of this yogurt to begin your next batch. Refrigerate for up to 2 weeks in an airtight container.
Crème Fraîche
(makes about 1 cup)
1 cup heavy whipping cream – NOT ultra pasteurized, if possible.
3 Tbs. commercial buttermilk or sour cream
Step 1: Heat the cream to about 180 degrees and let cool to about 110 degrees.
Step 2: Carefully stir in the buttermilk or sour cream.
Step 3: Incubate as for the yogurt.
I split the heavy cream and tried half with buttermilk and half with sour cream. There didn’t seem to be any difference in the taste or consistency of the result.
Both had a delicious nutty flavor, deeper than plain cream but in no way sour or tart.
I was a bit disappointed in the consistency: Both had thick layers on top but were not that much thicker than the starting cream. However, the change in flavor made the experiment worthwhile.
Moving out of the lab, here is an easy soup recipe that uses both your delicious crème fraîche and some more of that pesky summer zucchini:
Cream of Zucchini Soup
(adapted from “The Way to Cook” by Julia Child)
Serves 6 to 8
1 to 2 cups sliced onions
2 Tbs. butter
7 to 8 cups liquid: water, plus chicken or vegetable stock and/or milk – 4 cups for the base; the rest added later
1/2 cup raw rice
Salt and freshly ground pepper
1 1/2 pounds zucchini (5 zucchini, 8-inches long)
1/4 tsp. dried tarragon leaves, or sprigs of fresh tarragon
1/2 cup crème fraîche
Decoration: sprigs of fresh tarragon or minced fresh parsley.
Step 1: Make the soup base. Sauté the onions slowly in the butter for 7 to 8 minutes, until tender and translucent.
Step 2: Add 4 cups of liquid and the rice and simmer about 20 minutes, until the rice is very tender.
Step 3: Trim the ends off the zucchini and wash but do not peel them. Grate them on the coarse side of a hand grater or in a food processor.
Step 4: Simmer 3/4 of the grated zucchini and the tarragon in the soup base 5 to 6 minutes.
Step 5: Purée the soup in a blender or food processor, adding more liquid if necessary. You will have smooth, creamy, slightly thickened purée.
Step 6: Return the soup to the pan, add the crème fraîche and the remainder of the zucchini shreds and simmer 2 to 3 more minutes, until the zucchini is tender.
Step 7: Ladle into bowls and sprinkle with fresh tarragon or minced parsley.
