Cream's ability to whip up light and frothy is one of the culinary world's happiest accidents, a random quirk of fat and physics. The heavy cream's high fat content enables it to trap air as your whisk passes through it, creating millions of fine bubbles that double the cream's volume. Real whipped cream is rich, but its flavor is infinitely superior to that of its artificial counterparts. It's easy to make at home, with a mixer or manual whisk.
Refrigerate a glass or metal mixing bowl, as well as the whisk or beaters you'll use to whip the cream. This step is optional, but cream whips best when very cold, and chilling the bowl and beaters for as little as 20 minutes can make a decided difference.
Lock the bowl into your stand mixer, or -- for a hand mixer or whisk -- set the bowl on a damp cloth or rubber mat to keep it from moving. Pour in a cup or 2 of very cold heavy cream. If you like your cream sweetened, add up to a tablespoon of granulated or extra-fine sugar for every cup of cream.
Start your mixer at moderate speed, and beat the cream until it loses its initial bubbly appearance and begins to form a finer mousse. This takes 3 to 5 minutes with a power mixer and often a few minutes longer with a whisk.
Increase your whisking speed to moderately high. The cream will increase noticeably in volume and start to thicken. Initially, it will have a soft, batter-like consistency that barely holds the mark of the beater as it passes. After a few more minutes, it will begin to hold its shape -- "soft peaks" -- and you can add a splash of vanilla or other flavorings if you wish. At this stage, the cream can be spooned onto desserts.
Continue whisking for a few more minutes, if desired, until your cream arrives at the characteristic, soft-but-firm "stiff peaks" stage. At this point, if you lift out your whisk or beater, the cream should form a stiff peak that holds its shape and has a clean, sharp edge. Stiffly whipped cream can also be spooned onto desserts, but for a more decorative effect, it can be piped from a pastry bag to make rosettes, shells or other shapes.
When you whisk or beat heavy cream, the physical force of your whisk or beater passing through the cream disrupts the bonds holding the fat molecules together in tight globules. Those molecules quickly re-connect, but the whisk leaves an air bubble in its wake that's trapped inside the fat.
Whipped cream will deflate within a few hours at room temperature, as the fat globules soften and lose their ability to contain their trapped air. It retains its shape and volume better if refrigerated, or can be stabilized with unflavored gelatin to last until the next day.
Cream can be whipped quite successfully in a plastic bowl, but plastic doesn't retain the refrigerator's chill and therefore won't help your cream whisk more effectively.
If you continue to whip your cream past the stiff-peak stage, it will become grainy as small flecks of butter form in the cream. Stop as soon as your cream holds its shape to minimize this risk.