r/AskCulinary • u/Apart_Value9613 • 2d ago
[Custard?] Recipe calls for mixing egg yolks, milk, sugar, then boiling it for four minutes. Why don’t the egg yolks become scrambled? Technique Question
The closest term I could find was custard. When you boil egg yolks they become solid and powdery. But why don’t they split when boiled over the stovetop? (The recipe is an Ottoman dessert called “Keşkül” if anyone is wondering)
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u/thymiamatis 2d ago
Boil may be a translation error. You heat the eggs for custard and boiling would indeed curdle the custard. If the ratios are the same as an average custard recipe (there can be small variations), just make custard out of those ingredients.
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u/Apart_Value9613 2d ago
Thank you, today I learned that “boiling” and “simmering” are different words. But still, why doesn’t simmering cause the eggs to curdle?
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u/GlassHoney2354 2d ago
Simmering is still not the correct term. Simmering is basically almost boiling, like 90-95C in this case.
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u/Apart_Value9613 2d ago
What would “slowly bubbling” be?
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u/FlamingTelepath 2d ago
Any recipe worth following will tell you an exact temperature
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u/Grim-Sleeper 2d ago
Yes, this is generally true.
But then again, custards are such a basic technique, a lot of recipes assume you already know what you are doing and they just need to give you the ratios for the particular variation of custard that you are making today.
This is like boiling an egg. A recipe for tea-eggs might give you all the ingredients for the brining solutions or marinade. But you won't find anyone spelling out the temperature of the water to boil the eggs. They might or might not give you guidance on number of minutes to boil, if they want to stear you towards hard- vs soft-boiled eggs. But that's about.
So, I do agree with you in principle. Temperatures are important and should normally be spelled out. But some things are so basic that a recipe author might just skip to the important parts.
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u/thymiamatis 2d ago
Heating eggs in the custard too high causes the proteins to separate from the water in the eggs. At a low heat, this doesn't happen but it will still cook and thicken the mixture. I love custard from scratch, it's worth doing.
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u/weedtrek 2d ago
I wonder if it was meant to be "double boil" as in a double boiler, which was the traditional way to make custard.
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u/bhambrewer 2d ago
I had a look at three different recipes, and two of them temper the hot milk into the eggs, the third did it all in one go. I default to tempering a custard, but I would guess the all in one technique relies on slow gentle heating to achieve the same end as tempering.
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u/Just_Tamy 2d ago
Custard that is thickened with starch has to "boil" (though it happens at 85 degrees c) for at least a minute. This is because of an enzyme found in egg yolks (amylase) that breaks down starch. If you don't cook it enough it will be thick when you make it but the next day will be very thin.
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u/AdDramatic5591 2d ago
Most recipes for Keşkül do have a starch, curious the op one doesnt.
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u/Acrobatic-Ad584 2d ago
Yes, I see that now, it is in fact an almond pudding made with starch in some recipes
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u/Apart_Value9613 2d ago
Sorry I don’t follow, how does starch prevent the egg yolks from cooking?
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u/Just_Tamy 2d ago
Sorry I read your question wrong before answering. Starch makes eggs not cuagulate because the starch molecules swell and gel before the proteins in the egg can tightly bond. They form a physical barrier and limit to which degree the egg can bond, thus making your egg mixture more temperature resistant. With enough temperature your egg will cook though.
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u/Apart_Value9613 2d ago
Sorry I made it difficult due to English and bad communication skills. Thank you for teaching me the “anti-cooking” spell. Have a nice day!
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u/Acrobatic-Ad584 2d ago
there is no starch
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u/Just_Tamy 2d ago
Op's recipe uses starch.
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u/Acrobatic-Ad584 2d ago
Maybe I cant see the whole post but I cant see any starch there at all except in egg yolks
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u/AdditionalAmoeba6358 2d ago
Ok, so what everyone is saying here is true, but only PART of the chemistry.
There is this fun deal in Chem called the Vant Hoff factor. This comes into play in four situations you can deal with in cooking (to some degree): boiling point elevation, freezing point depression, osmotic pressure, and vapor pressure lowering.
This is the effect that we are use when putting salt down to melt ice on sidewalks.
So for every molecule of something added to a “liquid” has this effect, some much more than others.
So for every sugar molecule dissolved in the custard, it will raise the pressure on the solution, allowing it to reach a higher temperature before it curdles.
Been a while but I think I explained that properly
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u/Mammoth-Turnip-3058 2d ago
It definitely shouldn't be boiled, it would scramble. Custard needs to be heated slowly and constantly stirred until thickened, it should be able to coat the back of a wooden spoon. It shouldn't go higher than around 80°C or it'll start to curdle. You could add flour to it before cooking but then it wouldn't be custard, it would be creme patissiere.
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u/Acrobatic-Ad584 2d ago
Looks like confectioners custard. I think I would mix the eggs etc in a bowl over boiling water, water not too close to the bowl, rather than in a saucepan on stovetop.
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u/chefkittious 2d ago
Boil, no. Simmer maybe. As others have said you would do best to temper the hot liquid into the yolk to avoid them from cooking too far too quickly.
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u/amvad555 2d ago
Apologies in advance if I'm hijacking this post, but what can you do with custard? I made a batch from a recipe I was interested in but it tastes too eggy. What can I do with it? It's in my freezer now.
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u/Iscan49er 2d ago
Custard should not taste eggy. But all the best ice cream starts with a custard. If it’s already frozen, try semi thawing it, beating it to break up ice crystals, add flavouring like crushed berries, stir through and refreeze. Otherwise a liquid custard is poured hot over sponge puddings or fruit pies.
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u/OberonSilk 2d ago
I hadn't heard of fruit pies with custard. Would you tell us more about those?
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u/thejadsel 2d ago
You serve it with a pouring custard in very much the same way as ice cream. Very popular some places. If you're interested in trying that, it should be easy to find recipes for crème anglaise.
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u/amvad555 2d ago
Well, that's an idea I never thought of. The custard recipe called for eggs. I was hoping it would come out like creme caramel, but wasn't even close!
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u/Mammoth-Turnip-3058 2d ago
Creme caramel is a custard base but not thickened on the stove, it's cooked in a bain marie in the oven with a caramel base on the bottom 😊 same as a creme brulee, bain marie in the oven then sugared and torched or if you need a lot done quickly then a caramel poured on the top 😁
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u/Grim-Sleeper 2d ago
Mix with stabilized whipped cream to make diplomat cream, then fill in egg puffs or beesting cake.
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u/CheeseFromAHead 2d ago
You can also temper your eggs before you cook them for custard and they won't scramble. I saw Alton Brown do it.
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u/texnessa Pépin's Padawan 1d ago
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