3. Whipped Cream
Unlike eggs,
in which proteins provide the structure for foam, cream relies on fats to provide the
structure for a foam when whipped. During whisking, fat globules in the cream lose their
outer membranes, exposing hydrophobic portions of the molecules. These exposed parts of
the fat globules either bind with other fat globules or align themselves to orient the
stripped region with an air bubble, forming a stable foam once enough of them have been
aggregated together.
When working with whipped cream, keep in mind that the fats provide the structure. If
the cream gets too warm, the fats will melt. This is why whipped cream can’t be used to
provide lift in most baked goods: the cream will melt before the starches and gluten in
the flour can trap the air. Be sure to chill your bowl and the cream before
whisking.
Note:
Whipping high-quality cream increases its volume by about 80%, while whipped egg
whites can expand by over 600%!
Percentage of fat in dairy products. If the cream doesn’t have enough
fat, there won’t be enough fat globules to create a stable foam.
One thing I notice about your posts is the number of
variations you go through. Do you think people have a fear of trying variations when
they go into the kitchen? I think a lot of times people don’t like wasting food. There is a whole culture
where wasting food is something that you don’t do. I totally agree with that, but when
you’re trying to learn how to do something it’s inevitable that you will make mistakes.
There will be some waste; that’s something people shouldn’t shy away from. When you’re
trying a new fancy dish for the first time and you’ve never used the ingredients, you
might use too much. For example, Vietnamese fish sauce is a wonderful ingredient, but if you use a
little bit too much it ruins the dish. What do you do at that point? If you eat it you
might be turned off from fish sauce for the rest of your life. There is a lot of food
waste that goes through my kitchen. There wouldn’t be as much if I weren’t running
Cooking for Engineers, but it’s really important to experiment. It’s one thing to read a
cookbook, but once in a while it’s important to deviate and try something completely
new. 
Time and activity bar chart for the Original Tiramisu.
Sometimes, these mistakes can be expensive; you might ruin your pot.
Sometimes they will reveal something awesome. In some recipes, you’re told to be sure to
not burn the garlic, but then if you experiment and do overcook the garlic, it becomes
these little crispy bitter pieces that work really well with certain types of
vegetables. People want to get it right the first time. Part of that is due to not
wanting to waste the food or the money, but the other part is they haven’t gotten to the
point where they’re enjoying doing it over until they get it right. Have there been any particular recipes whose success has
caught you off-guard? Tiramisu is the recipe that launched Cooking for Engineers. I posted the tiramisu
recipe, and three days later I was getting maybe 100 page views a day on that article.
Enough people saw it that I got attention from Slashdot, which wrote an article about
this new cooking website geared toward geeky people. Boom, I got a lot of readership. So
much so that I had a little trouble keeping up with the number of people who were
looking at the web pages on the little server that I was running on. The tiramisu recipe that we have on Cooking for Engineers is a bit more simplified
than many of the other tiramisu recipes. I spent a lot of time developing it. I wanted
to come up with something that inexperienced cooks could do without extra steps, so I
came up with a method where the cream is mixed in with the Mascarpone cheese to produce
the lighter, fluffier texture. I modified the amount of ingredients so that it was well
balanced. The tiramisu recipe is probably one of the best we’ve ever tasted, and very
simple to make. It’s called “simple tiramisu.” After the success of the simple one I
included one that was closer to what the original tiramisu was as well, to let people
compare them.
 Time and activity chart for Simple Tiramisu.
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Note:
Cream whippers—canisters that can be
filled with a liquid and then pressurized with gas (usually nitrous oxide)—are also a
form of mechanical leavening. The gas dissolves into the liquid and then, upon
spraying, bubbles back out of saturation, foaming up the liquid. From a structural
point of view, foams created this way are entirely different from foams created by
whisking: instead of a 3D mesh of surfactants holding on to the air bubbles, the air
bubbles are essentially just in suspension. This is why hand-whipped cream is more
stable than whipped cream from a can.
Compare the following two methods for making chocolate mousse. The
egg-white version creates a creamy, dense mousse, while the whipped cream version
creates a stiffer version. |
Chocolate Mousse (Whipped Egg White version)
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Chocolate Mousse (Whipped Cream version)
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In a saucepan, heat ½ cup (120g) of whipping or heavy cream to just below
a boil and turn off heat. Add 4 oz (115g) of bittersweet chocolate that’s been
chopped into small chunks.
|
Melt 4 oz (115g) of bittersweet chocolate in a microwave-safe bowl. Add 2
tablespoons (28g) of butter and 2 tablespoons (28g) of cream and whisk to
combine. Place in fridge to cool.
| |
Separate 4 eggs, putting 2 of the yolks into the saucepan and all the
whites into a clean bowl for whisking. Save the other 2 yolks for a different
recipe.
Whisk the egg whites with 4 tablespoons (50g) of sugar to soft peaks.
Whisk the cream, chocolate, and yolks together to combine. Fold the whites
into the sauce.
Transfer mousse to individual serving glasses and refrigerate for several
hours—overnight, preferably.
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In a chilled bowl, whisk 1 cup (240g) of whipping or heavy cream with 4
tablespoons (50g) of sugar to soft peaks.
Make sure the chocolate mixture has cooled down to at least room
temperature (~15 minutes in the fridge). Fold the whipped cream into the
chocolate mix. Transfer mousse to individual serving glasses and refrigerate
for several hours; overnight, preferably.
| |
Note
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Note
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The egg whites in this are uncooked, so there is a chance of
salmonella. While it’s rare in chicken eggs in the United States, if you
are concerned, use pasteurized egg whites.
|
Try replacing the 2 tablespoons of cream with 2 tablespoons
of espresso, Grand Marnier, cognac, or another flavoring
liquid.
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While steam doesn’t involve
mechanically trapping air as the other methods in this section do, it’s still a
physical process by which air is introduced into food. Most of the recipes given so
far also rely on steam generation as part of their leavening; few baked goods truly
rely on only one method for providing lift. Try this popover recipe, which is a
classic example of a baked good leavened by steam.
Popovers
Traditionally, these are made in specialized popover cups, which are
narrow cups with a slight slope to them and that have some heft to them, giving them
good heat retention. You can use muffin tins or ramekins instead.
Whisk together in a mixing bowl or blend in a blender:
1 ½ cups (380g) whole milk
3 large (180g) eggs
1 ½ cups (180g) flour (try half AP, half
bread)
1 tablespoon (15g) melted butter
½ teaspoon (2g) salt
Preheat both the oven and the popover cups or muffin tin at 425°F / 220°C.
Heavily grease the popover cups or muffin tins with butter: melt a few tablespoons
of butter and put a teaspoon in the bottom of each cup. Fill each cup about ⅓ to ½ full
with batter and bake. After 15 minutes, drop the temperature to 350°F / 175°C and
continue baking until the outside is set and golden-dark brown, about another 20
minutes.
Serve at once with jam and butter.
Notes
How does gluten affect the inside and crust of the popover? As an
experiment, make two batches of the batter, one with either cake or AP flour and
the second with a higher-gluten flour. Fill half the cups with one batter and the
other half with the second batter and bake them at the same time to eliminate the
potential for differences between runs.
Try adding grated cheddar cheese or Parmesan cheese for a savory
version, or sugar and cinnamon for a sweet version. You can also pour the popover
batter into a large cast iron pan (preheated), top with sliced fruit such as pears
or peaches, and bake to make a large, tort-like breakfast
pastry.
Don’t peek while these are baking! Opening the oven door will drop the
air temperature, causing the popovers to drop in temperature and lose some of the
steam that’s critical to their rise.
