I THINK I had real buttermilk once, when I was little. I think I remember my reaction. Yecch.

I probably wouldn't have liked yogurt either. It only goes to prove that mother is always right. My mother insisted my tastes would change when I grew up. Otherwise, how can you explain why I like baked potatoes with yogurt now instead of sour cream?

My reaction, and obviously that of others, to buttermilk is summed up perfectly by America's foremost author on the subject of food, M.F.K. Fisher. More than 40 years ago she was writing about a cold buttermilk soup in "How to Cook a Wolf":

"It is one of my growing number of Things I Do Not Mention Gastronomically. If I tell the smiling people who sip at it that it is made of mashed shrimps and especially buttermilk, they wince, gag and hurry away. So I say nothing, and serve it from invisible hogsheads to unconscious but happy hordes."

As an adult, I've never had real buttermilk; and if you don't live on a farm with a cow and a butter churn, and you are under 30 or 40 you probably never have tasted real buttermilk either. What you buy in the store today isn't.

Real buttermilk is the liquid that remains after the cream has been churned into butter, the whey. (How many of you have ever seen cream on the top of the milk in a bottle?) The bacteria that clung to the old-fashioned wooden butter churns naturally produced the lactic acid which soured the buttermilk.

How and when it was discovered that the buttermilk was not only drinkable, but produced a more tender and tangier baked product than regular milk isn't recorded in any book that I have found. But it isn't surprising that thrifty farm women found some use for the liquid in the bottom of the churn. The use of buttermilk as a refreshing beverage is found in Sanskirt writings. And Persians never drank sweet milk. They preferred buttermilk, with the cream skimmed off. They also liked the curds, mast , or yogurt.

Today's buttermilk is skim milk which has been cultured with bacteria to produce lactic acid. Sometimes flecks of butter are added to make it look like old-fashioned buttermilk. Unfortunately, those flecks add calories to what is essentially a low calorie drink (80 per eight ounces). Some people say the flavor of cultured buttermilk bears no resemblance to real buttermilk. Most people don't know. Some people claim that cultured buttermilk doesn't produce as fine a product as real buttermilk. Some of these people include the manufacturer of a new consumer product, cultured buttermilk powder.

Saco, a Wisconsin company, is doing for the home cook what the manufactures of butter have been doing for years for commerical users of buttermilk -- drying the whey that remains after the butter is churned, and selling it.

Over the years the number of butter processors has declined substantially in this country, and it became economically unfeasible to transport the residue of the churning to plants that could turn it into liquid buttermilk. By the '40s they had begun to dry it and sell it to commercial users. Until now, home cooks have had to rely on the cultured skim milk version.

Ray Sanna, vice president of Saco, says that product isn't as good as his company's dried cultured buttermilk powder. His product, made from real buttermilk and then cultured to make it more acidic, contains the emulsifiers found in real buttermilk but not in skim milk, emulsifiers known as lecithin. According to a company press release, "emulsifiers allow the shortening, flour and liquid to blend easier in the batter. This is the most important advantage of using real buttermilk in cooking and baking."

We decided to conduct a taste test to see if those emulsifiers made a difference. We cooked pancakes made with liquid cultured buttermilk and with the Saco Cultured Buttermilk Powder. If there was a difference it was negligible. Then we tried buttermilk biscuits. If there was a discernible difference, it was in the slightly greater degree of tanginess in the biscuits made with the liguid buttermilk.

What the dried product really has going for it is its convenience. If you don't drink buttermilk, what do you do with the remaining of the quart after you've made the biscuits (less than a cup) or chocolate cake (1/2 cup)? The dried product has a shelf life of a year. It also costs less.

But if you like to drink buttermilk or want to use it in a salad dressing, cold soup or sherbert, this product is not for you. It doesn't taste good unless it has been cooked.

Now that Americans are returning to their cooking roots, perhaps buttermilk will enjoy a renaissance. After all, we have taken to eating yogurt as if it were ice cream. Let's hope that what happened to yogurt won't happen to buttermilk. Can you see it now: buttermilk in 26 flavors, ranging from prune to cherry vanilla?

Whether you use liquid buttermilk or powdered, buttermilk adds a delicous tang to many dishes. If you are worried about your family's reaction, why not take a leaf from M.F.K. Fisher's book? While you are at it, why not set aside her delightful recipe for cold buttermilk soup, along with this other for plum sherbert, until the warm days of summer are here. They will come, you know. M.F.K. FISHER'S COLD BUTTERMILK SOUP (6 servings) 1 1/2 pounds shrimp, cooked and chopped 1/2 medium cucumber, finely diced 1 tablespoon minced fresh dill 1 tablespoon prepared mustard 1 teaspoon salt 1 teaspoon sugar 1 quart buttermilk

Mix together shrimp, cucumbers, seasonings; stir in buttermilk and chill thoroughly. PLUM SHERBERT (4 to 6 servings) 2 cups whole ripe red plums, about 7 3-inch stick of cinnamon 1 cup sugar 3 tablespoons lemon juice Grated rind of 1 lemon 1 1/2 cups buttermilk

Put plums and cinnamon stick in pan with 1/2 cup water. Cover and simmer gently for 10 minutes. Cool enough so you can handle the plums. Pit and puree them. You will need 1 cup puree. If all the skin does not puree, that's fine. It adds texture and color to the sherbert. Drain off the liquid. Return puree to pan with cinnamon stick, sugar, lemon juice and rind. lSimmer until sugar is dissolved. Remove cinnamon stick. Cool and add buttermilk. Mix well and pour into shallow trays for freezing. Freeze until almost firm. Remove sherbert from trays and place in chilled bowl; beat until smooth. Return to trays and freeze unti firm. Use within a few days. BUTTERMILK COTTAGE CHEESE DRESSING (1 1/2 cups) 1 cup cottage cheese 1/2 cup buttermilk 3 tablespoons white wine vinegar 1/2 teaspoon finely minced onion 1 teaspoon caraway seed (optional) Salt and pepper to taste

Blend ingredients in blender until smooth. Use with mixed green salad or with fruit. BEEF ROASTED IN BUTTERMILK (8 to 10 servings) 3 to 4 pound bottom round roast Salt and freshly ground pepper to taste 2 cups buttermilk 1 cup water 1 tablespoon wine or cider vinegar 1 large onion, sliced 1 small bay leaf

Rub salt into the meat. Brown meat in its own fat in heavy casserole. Drain off excess fat. Add buttermilk, water, vinegar, onion and bay leaf. Season with pepper. Bring to boil; reduce hear; cover and simmer 2 1/2 to 3 hours, until meat is tender. BUTTERMILK BISCUITS (About 20 biscuits) 1 3/4 cups sifted unbleached flour 1/2 teaspoon salt 2 teaspoons baking powder 1/2 teaspoon baking soda 1 teaspoon sugar 5 tablespoons butter or vegetable shortening 2/3 to 3/4 cup buttermilk

Sift al the dry ingredients together. Cut in the butter, or shortening, using two knives, a pastry blender, or your fingers. Slowly add the buttermilk until the dough pulls away from the sides of the bowl. You want a soft but not sticky dough. Knead the dough on a lightly floured board very gently for no more than 30 seconds. Pat dough to thickness of 1/4 inch. Cut with 1 1/2 inch biscuit cutter. Bake at 450 degrees for 10 to 12 minutes. Serve immediately.

For browner biscuits, brush tops with milk or butter. If you want biscuits that are crusty all over, place them an inch apart on the baking sheet; otherwise, close together. BUTTERMILK WAFFLES (About 6) 2 cups unbleached flour 1/4 teaspoon baking soda 1 1/2 teaspoons baking powder 1 tablespoon sugar 1/2 teaspoon salt 2 eggs, separated 1 3/4 cups buttermilk 6 tablespoons melted butter

Sift dry ingredients together. Beat yolks until light; beat in buttermilk and melted butter. Combine buttermilk mixture with dry ingredients with a few swift strokes. Beat whites until stiff, but not dry. Fold into batter. Prepare waffles according to directions that accompany waffle iron. BUTTERMILK MARINADE (About 2 cups) 2 cups buttermilk 2 cloves garlic, put through press or finely minced Salt and freshly ground black pepper

Use this mixture to marinate beef, pork lamb or chicken. Then incorporate it into a sauce for the meat. BUTTERMILK MIX FOR PANCAKES AND WAFFLES (Makes about 10 cups mix) 2 cups dry buttermilk powder 8 cups unbleached flour 2 1/2 tablespoons sugar 8 teaspoons baking powder 4 teaspoons baking soda 2 teaspoons salt

Combine all ingredients in large bowl and mix until thoroughly blended. Store in tight fitting container in cool dry place. Keeps 6 months or longer.

TO MAKE PANCAKES: Combine 1 beaten egg with 2 tablespoons melted butter and 1 cup water. Whisk in 1 1/2 cups mix until blended. If you want a thinner batter, add more water. Follow standard directions for pancakes. Makes about 10 four inch pancakes.

TO MAKE WAFFLES: Combine 2 1/2 cups mix with 2 cups water, 3 egg yolks and 4 tablespoons melted butter. Beat just until blended. Beat whites until stiff and fold into batter. Bake according to waffle iron instructions. Make 3 or 4 large waffles. DEVIL'S FOOD CAKE (12 servings) 1 pound box light brown sugar 3/4 cup butter 3 eggs 2 teaspoons vanilla 3 squares unsweetened chocolate, melted 2 1/4 cups sifted cake flour 3/4 teaspoon salt 2 teaspoons baking soda 1/2 cup buttermilk 1 cup boiling water

Cream the sugar, butter, eggs and vanilla together until light and fluffy. Stir in the melted chocolate. Sift together flour, salt and baking soda. Add dry ingredients alternately with buttermilk to creamed mixture. Add boiling water (batter will be thin). Pour into 9 by 13 inch baking pan that has been lined with greased wax paper. Bake at 350 degrees for 45 to 60 minutes or until cake tests done. Cool for 10 minutes on wire rack before removing from pan. Frost with chocolate frosting when cooled. CHOCOLATE FROSTING 1 pound box confectioners' sugar 3 tablespoons butter 2 teaspoons vanilla 1 egg 4 squares unsweetened chocolate, melted pinch salt 1/4 cup hot water, approximately

Cream together the sugar, butter, vanilla, egg, chocolate and salt. Add hot water slowly until frosting is of correct spreading consistency. Beat until fluffy. Swirl on cooled cake.