Generations of home-bakers have known the secret: You can achieve an exceptionally moist
and dense yet light and fluffy cake by adding instant pudding powder to your batter. I'm
going give you a recipe for just such a cake, and we're going to learn the science of how
and why this works so well. Also, if you don't want to put a box of instant pudding in your
cake, I'm gonna show a DIY method for achieving the exact same effect.
So we were just up in the Tennessee foothills of the Great Smoky Mountains — visiting
my mother-in-law, Gretchen. This is her signature cake. She got it from her mother, who got
it from a neighbor lady named Hattie.
"So we've always called it Hattie's cake. And a 75-year-old woman in my Sunday school
class tasted it and said she calls this 'the better-than-sex chocolate cake,' so I think
that kinda describes it."
Now sneer all you want, but this starts with a 15-ounce box of yellow cake mix. Damn good
stuff. Then comes the 6-ounce box of instant chocolate pudding powder. It's important that
it be "instant" — I'll show you why in a minute. Then come three eggs, an 8-ounce tub
of sour cream, 3/4 of a cup of water, 2/3 of a cup of vegetable oil and a teaspoon of
vanilla. Beat it up until nice and smooth. Oh look at that, it looks pudding-y, doesn't
it? Mix in a cup of chocolate chips, and it's time to put this in a bundt pan, and here
is another secret ingredient:
"Baker's Joy."
Non-stick spray with flour inside it.
"That's what you spray on the pan so that it doesn't stick, and it really is kind of
a miracle."
Bake at 350 F for 50 to 55 minutes. You'll know it's done with the edges start to brown
and pull away from the sides, and a knife or a skewer or something to the center comes
out clean. Let it cool for a few minutes before turning it out onto a plate, and here is when
we'll find out if it stuck.
"So cross your fingers."
"Ah, perfection."
Now what I love about this cake is the texture. Look at how kinda jiggly it is. It kinda moves
like pudding. It's gelatinous. Hence, "Jell-O."
Now I think that I can bake a cake this moist and dense without pudding powder in it, but
it wouldn't be as soft, and it wouldn't be as light — light in the sense of there would
be a lot more fat in it. Furthermore, this stays soft and moist for days after baking,
if it lasts that long. Why is that? Well let's wrap up a piece and take it over to Dr. Curtis
Luckett, a food scientist at the University of Tennessee, Knoxville. He says the secret
here appears to be the second ingredient listed on the pudding box after sugar: modified corn
starch.
"The modified starch of instant pudding is gonna have a higher water-binding capacity.
Basically, they've modified the starch enzymatically, physically or even chemically to better interact
with water molecules. So maybe in this cake, they're binding to the water molecules, helping
to create a more moist, a more dense cake."
If you have any regular cornstarch in your kitchen, you can see this water-binding capacity
for yourself right now. Just whisk it into some water and bring it to a boil. The starch
molecules, which are normally in tight little grains, will open up and form what Dr. Luckett
would call a matrix. That's a structural web that holds all the water inside it in a gel.
How is this different from the "modified" stuff in the pudding box?
"This is probably a pre-gelled starch. To disrupt that granular structure, you often
need to cook in the presence of water to get the amylose amylopectin, the two actual macro-molecules
that make up starch, to leach out into solution and start forming the food matrix."
But in the case of this modified stuff, you don't have to cook it. You can mix it right
into cold liquid and it gels. The manufacturers busted up the starch granules in advance,
with enzymes, or chemicals — maybe even just by boiling it in water and drying it
out again. And look — this, in effect, is what is in your cake — holding more water
and fat than a cake can normally hold without collapsing.
Dr. Luckett figures another way the pudding starch has been modified is to prevent the
amylose and amylopectin from bunching back together into a hard structure. This is a
process called "re-associaiton" that leads to a result called "retrogradation."
"That's the primary mechanism of staling. So, when bread stales, it's because those
starch molecules have migrated close to each other and started to re-associate, and it
kinda pushes water out in that process called retrogradation."
This is why Hattie's cake stays moist and soft for days after you bake it. And there
you go — all the reasons why instant pudding powder is magic inside cakes. Now some people
might be freaked out by the idea of adding a "processed food" to their cake. For what's
worth, Dr. Luckett has little kids, like I do, and I asked him:
"Anything in that ingredient list that you'd pause before giving to your kids?"
"None."
And get this, you don't even have to use instant pudding powder if you don't want to. I mean,
it's got sugar and flavorings and stuff that you might not want or need in your cake. You
can buy unflavored, pre-gelatinized starch on the internet. How much should you use?
According to this 2001 study out of Turkey, the magic number is 10 percent. Replace 10-percent
of the flour in your recipe, by weight, with pre-geletanized starch. Any more than 10 percent,
they found, makes the batter too thin — it can't trap gas when it bakes, and you get
this flat, overly-dense cake.
But yeah, replace 10 percent of your flour with this magic powder and Bob's your uncle,
as the Brits say.
Or you could just buy the boxes and make Hattie's Cake — it's a family tradition for a reason.