Did this pudding go wrong?

Made this custard from the latest issue of Food & Wine:

http://www.foodandwine.com/recipes/nati ... my-custard

The final texture was, for want of better words, fine-grained. Either this is correct (not mentioned in the recipe) or something went wrong in the cooking. I am experienced in making custards, from creme anglais to creme brulee, and have not had this problem before. However, I don't think I've ever made one with corn starch.

I carefully tempered the eggs; there was no scrambling during that time but I strained the liquid anyway. Early in the final cooking the liquid was quite foamy but there was no sign of graininess during thickness and taste testing. The liquid never boiled or simmered and cooked for the suggested length of time only. I did change the whole milk to 1/2 cream and 1/2 low fat milk because I had some leftover cream.

I know there can be a problem with the thickening power of corn starch if overcooked but the final consistency was quite acceptably thick and was a success except for the graininess which was offputting for me in a custard.

Any ideas? Thanks in advance for any help.

This is basically a recipe for a cinnamon-flavored pastry cream. The classic technique would be to whisk the sugar, egg yolks and (sifted) cornstarch together. Then temper that mixture with the hot liquid. Then return the enitre mixture to the stove and bring to a boil. As soon as the mixture boils it is done. I don't understand where the 18 minutes comes from in this recipe. BTW - the cornstarch is what allows you to bring this mixture to a boil without curdling. Do make sure to sift the cornstarch and make sure the egg mixture is nice and smooth before tempering or you will get little lumps.

Just a guess, but I think your temperature for cooking the custard may have been a bit too low. The cornstarch did not fully gelatinize and merely swelled up because of the moderate heat, making the custard grainy.
As chefmike said, letting it boil, at most a minute or two, should be enough to finish it off. The recipe should've provided a temperature for the 18 minute cooking time. 185 maybe?

Hi,

Just for fun, I looked at two pastry cream recipes, one from Epicurious with ingredients listed as:

2 1/4 cups whole milk
6 large egg yolks
2/3 cup sugar
1/3 cup cornstarch
1 vanilla bean, split lengthwise

as well as pastry cream on Cook's Illustrated with the following ingredient list:

Pastry Cream
2 cups half-and-half
1/2 cup granulated sugar
pinch table salt
5 large egg yolks, chalazae removed (see note)
3 tablespoons cornstarch
4 tablespoons unsalted butter (cold), cut into 4 pieces
1 1/2 teaspoons vanilla extract

The proportions of both cornstarch and egg yolks are greater in the other recipes than yours from Food and Wine. Plus there is no need for added water, when the cornstarch can be dissolved into the egg yolks.

4 cups whole milk
One 2-inch strip of lemon zest
1 cinnamon stick
1/4 teaspoon salt
1 1/4 cups granulated sugar
8 large egg yolks
1/4 cup cornstarch, dissolved in 1/4 cup water
1 teaspoon pure vanilla extract
Ground cinnamon, for garnish

The Food and Wine recipe boils the mixture for 18 minutes, while the other two recipes have the cooking stop once the sauce has thickened citing 1 minute and 30 seconds respectively.

If the information What is the difference between thickening with flour and corn starch? is factual:

Too Much Stirring: Excessive or rough stirring with a wire whisk or even a spoon may break the starch cells and cause the mixture to thin out.

Excessive Cooking: Simmering or boiling a corn starch thickened mixture for an extended period of time may cause the starch cells to rupture and the mixture to thin.

Ultimately, I would borrow the ideas for flavoring a pastry cream with cinnamon, then find a better recipe. The problem wasn't you, it was the recipe.

Regards,

Two things come to mind:

Did the sugar sit with the uncooked eggs without being whisked, for any length of time? If, while you are waiting for the milk mixture to simmer, you combine the sugar and eggs too early but do not whisk often, the sugar can start to coagulate the eggs, which will result in a grainy final texture.

Also, I agree that the 18 minutes thing is wierd. Over moderate heat, the eggs would scramble. At the same time, the recipe only says to 'thicken' the mixture and neglects to mention that cornstarch must be brought to a boil to activate its gelling properties. I always put the tempered egg mixture back on mod. heat, and whisk feverishly just until the mixture thickens and one or two big thick bubbles come up. This takes about one minute. Then i remove it from the heat and transfer it to a new container to stop the cooking.

So yeah, I'd say your recipe is just bad.

bnowell724 wrote:Two things come to mind:

Did the sugar sit with the uncooked eggs without being whisked, for any length of time? If, while you are waiting for the milk mixture to simmer, you combine the sugar and eggs too early but do not whisk often, the sugar can start to coagulate the eggs, which will result in a grainy final texture.

I always like to know more about food chemistry, thank you for this lesson.

Regards,

In my experience, the most common reason for grainy textured pudding is - by far - failing to stop stirring and cooking once the thing thickens up. It's silly for a recipe to call for "18 minutes" of cooking, given how many variables there are which make it impossible to give a precise time. At a minimum, the recipe ought to say "or until it reaches the thickness of mayonnaise," or something like that. Natilla should be cooked over low heat for as long as it takes to get mayo-like, then you have to stop the cooking and stirring right away.

To angrychefmike's suggestion to treat this like a classic pastry cream, which one brings to a boil right away, I say that while that would work, it would not produce natilla. The slow cooking is an integral part of the dish, producing a texture that's less firm and more viscous than a classic pastry cream. With starch-thickened custards, the quicker you heat them up, the firmer the final product will be.

Thanks, everyone for their truly fascinating comments and suggestions. Been away for a couple of days and couldn't respond timely. A couple of additional comments:

1) The heat was moderate/low the whole time. There was never any movement to the liquid which is how I always cooked custards. After a few minutes the foam - should there be foam - had settled down, and it was about the consistency where I would take a custard w/o cornstarch off the heat. It never seemed to get much thicker and I had no further reference point for when it would be finished other than to continue to the time suggested.

2) Interesting about the corn starch gelatinizing/boiling the liquid. I take the point but I've gone over the recipe a couple of times and see no instructions to do that.

3) The egg yolks did sit whipped into the sugar for a couple of minutes while the milk/cream heated up. I had no idea that might happen.

4) Definitely no egg scrambling. Don't ask me how I know what that looks like.

5) The final product was as KennyZ described but grainy.

I hope to try again soon as I still have some cream. My wife thought the taste was delicious. Me, I thought it was good but a little too sweet. I left off the additional cinnamon as the bark gave it enough flavor for me.

I'm sorry i didn't even see what the title of the recipe was-just saw it was a pudding and briefly looked over the ingredients+method. After looking online I see that natilla is traditionally cooked for much longer than a normal pudding or pastry cream , and on a lower heat(as Kennyz pointed out). Sounds more like creme anglaise, which is not meant to be boiled at all, just slightly thickened-although there is no starch in a traditional creme anglaise. Very interesting, this sounds tasty and I will def have to make it some time.

The reason that sugar will coagulate the eggs if left sitting, or so I was taught in school, is that it is actually cooking them. Keeping the mixture moving by whisking almost constantly should keep lumps from occuring, though. I usually do not combine my sugar and eggs until just before i will be mixing them into whatever other ingredients are in the recipe.