Whipping cream, the luxurious layer that rises to the top of nonhomogenized milk, contains at least 36 percent milk fat and is sometimes sold as heavy cream. Light whipping cream contains between 30 and 36 percent milk fat. Whipping cream adds a rich flavor and creamy consistency to both desserts and savory dishes. It should have a smooth texture but might contain chunks. The reasons are as varied as a minor manufacturing glitch to overcooking.
The most common reason whipped cream would have chunks in it is because you whipped it too much, causing tiny bits of butter to form in the whipping cream. When this occurs, you can simply remove the lumps with a spoon. In the future, place the whipping cream in a cold bowl and whip it just until stiff peaks form. Watch it closely so that it doesn't turn to butter. Flavor whipped cream with powdered sugar, vanilla or cocoa, depending on the dessert.
Another reason whipping cream might be chunky is if the product has expired. Check the expiration date and give the whipping cream a whiff. If you detect a sour smell, especially after the expiration date, the whipping cream has curdled and thickened. At this point, there's nothing to do but throw the cream out. Occasionally, though, whipping cream may contain a few chunks even when the cream is fresh. These chunks are bits of butter. If you are certain the cream doesn't taste or smell sour, it's safe to use. Strain the butter chunks out if you're making whipped cream. If you're using the cream in a sauce or soup, the butter will melt and add flavor.
When dairy products are heated, the proteins in them can cook and develop chunks -- similar to the process of scrambling eggs. Low-fat dairy products are more likely to curdle than whipping cream, but in rare cases, cream can curdle. Add whipping cream to soups and sauces at the end of the cooking time, and heat it slowly and gently. Avoid boiling whipping cream unless a recipe specifically directs you to do so. If heated whipping cream has curdled, you might be able to save it. Heat more whipping cream over low heat, and slowly stir the curdled sauce into the new portion of whipping cream.
Less frequently, whipping cream may become chunky if it's mixed with acidic ingredients, such as wine, vinegar or lemon juice. Perhaps you've reduced a wine sauce for meat and you want to add cream to the sauce. Reduce the heat so that the sauce isn't boiling before you add the whipping cream. Add just a few tablespoons of the cream at a time to prevent chunks from forming.
Perhaps the chunks in your whipping cream are caused by bits of gelatin. Stabilized whipping cream, often used for frosting cakes, has a bit of unflavored gelatin added to it to give the cream structure and preserve its freshness. Soften the gelatin in warm water, and then add a bit of whipping cream to the warm water. If you pour the gelatin water directly into your bowl of whipping cream, the gelatin may form clumps.