Yuzu crémeux - boil or not?

[Rajala]

I was looking for a yuzu crémeux recipe and found one at callebaut.com (https://www.callebaut.com/en-OC/chocolate-recipe/1357/yuzu-and-white-chocolate-cream-cake)

 

There's one things I find interesting with this recipe, and that is that I should bring eggs, puré, water and sugar to a boil. Do they really mean this? Or is the idea that I should bring it to 82-84 degrees and that's the boil? Or is it sometime safe to bring eggs to the boiling point in certain mixtures? From what I've learned so far is that you never want to boil eggs, to avoid getting a "omelette".

 

Bonus question: recipe calls for 25 grams of gelatin, but it doesn't say what kind of gelatin. Does anyone have any idea what kind of gelatin that are normally used in Callebaut recipes? I guess it's not gelatin mass since they want you to "soften it in cold water".

[pastrygirl]

If there is enough acid, you can boil it without it scrambling.  You probably still want to strain out any little bits that may occur, but I have brought lemon-curd type mixtures to a boil without issue. 

 

As for gelatin, if you have leaves then weigh them and see if that number makes sense.  I have bronze leaves, not at my kitchen right now so I can't weigh them, but I'd guess 4 or 5 grams per leaf?  What type(s) of gelatin do you have available?

[gfron1]

Generally leaves are 2-2.5 g I believe. I know my silver are for sure. As for what the recipe is calling for. That would be 10 sheets of silver...I can't imagine doing 25 g powder in that recipe. You'd have a brick. Even 10 sheets seems high to me but maybe not. For comparison, here's a recipe I use often:

60 gm of sugar for a dry caramel

360 gm of heavy cream

seed from 4 vanilla beans

120 gm yolks

3 gm of gelatin

 

So that would be a sheet and a half (mas or menos) silver for 540g recipe (actually I would consider it a 480 g liquid recipe). A sheet a pound (very crudely).

 

BTW, this is a huge pet peeve of mine with professional recipes. Be clear on your gelatin, cream, butter %, etc. 

[jmacnaughtan]

For the gelatin, that'll be the weight in powder or sheets - it comes to 1.49% of the total recipe weight.  Both forms are essentially identical, and you generally want it to be somewhere between 0.5 and 1.5% of the weight, depending on other thickeners, consistency, etc.

 

It should be fine to bring it to the boil.  Just do as @pastrygirl recommends and strain it out.  I'd recommend hitting it with a stick blender as well when you incorporate the butter.

[Rajala]

9 hours ago, pastrygirl said:

If there is enough acid, you can boil it without it scrambling.  You probably still want to strain out any little bits that may occur, but I have brought lemon-curd type mixtures to a boil without issue. 

 

As for gelatin, if you have leaves then weigh them and see if that number makes sense.  I have bronze leaves, not at my kitchen right now so I can't weigh them, but I'd guess 4 or 5 grams per leaf?  What type(s) of gelatin do you have available?

 

Thanks. Didn't know that. How can one know if there's enough acid? 🤔

 

I have sheets, platinum type. Weighing the sheets doesn't work, from what I've been told. Since a bronze one weights a lot more than the platinum one. You should think like "a bronze one is 5 grams. 20 grams in total which means 4 sheets, which should also be around 4 sheets of platinum." Not sure if that works over the whole chart, but I've learnt that at least.

 

9 hours ago, gfron1 said:

BTW, this is a huge pet peeve of mine with professional recipes. Be clear on your gelatin, cream, butter %, etc. 

 

4 vanilla beans?! That is an expensive recipe.  And I agree with you, how hard can it be to let the readers know that it's gold sheets in use or mass. Reading So Good.. magazine, you can easily see things like here. 10 grams of gelatin, and you stand there with a question mark over your head. Chefs like Coppel are always clear with what they're using though. 

 

2 hours ago, jmacnaughtan said:

For the gelatin, that'll be the weight in powder or sheets - it comes to 1.49% of the total recipe weight.  Both forms are essentially identical, and you generally want it to be somewhere between 0.5 and 1.5% of the weight, depending on other thickeners, consistency, etc.

  

It should be fine to bring it to the boil.  Just do as @pastrygirl recommends and strain it out.  I'd recommend hitting it with a stick blender as well when you incorporate the butter.

 

That's an interesting approach! Looking at the percentage of the total. A chef once told me to use 8 sheets per liter of liquid, and that would make a good mousse. This is not a mousse though.  

[Shalmanese]

certain coagulation inhibitors can cause eggs to remain fluid even at boiling temperatures. Pastry cream, for example, uses cornstarch to keep eggs from scrambling even after being boiled for several minutes (which is required to deactivate the amylase enzyme). Sugar, water, starches & acids all inhibit coagulation and require you to bring the mixture to a higher temperature before gelling compared to plain eggs.

[Rajala]

1 minute ago, Shalmanese said:

certain coagulation inhibitors can cause eggs to remain fluid even at boiling temperatures. Pastry cream, for example, uses cornstarch to keep eggs from scrambling even after being boiled for several minutes (which is required to deactivate the amylase enzyme). Sugar, water, starches & acids all inhibit coagulation and require you to bring the mixture to a higher temperature before gelling compared to plain eggs.

 

That's interesting, thanks.

[keychris]

My gold sheets are spot on 2g per sheet if that's any help

[Cahoot]

I though acidity decreased the temperature at which the proteins in eggs denature and coagulate, not increased it?

 

I found a table for fruit cremeux recipes from Les vergers Boiron, and it also calls for bringing all ingredients except the butter and gelatin to a boil. I found a possible explanation I found for why this is possible from Paula Figoni's How Baking Works: "Dairy proteins also likely interact with egg proteins, firming up the gel. Imagine egg custard made with water instead of milk. The custard would be very soft and barely set."

 

So my theory is by replacing the dairy with fruit puree, removing the dairy proteins is enough to allow the mixture to boil without coagulating. For reference if anyone's interested, the table can be downloaded from their website (scroll down and select the "Download our basic preparations for pastry chefs" option), or I took a screenshot of part of the table:

 

But some follow-up questions I had were:

1) How come some preparations (such as this one) call for bringing everything up to a boil together, instead of the traditional method of heating the liquid first and tempering the eggs? 

 

2) Later in that document, they say "To fill eclairs, we recommend using the cremeux or two fillings: macaroon compote 1/3 – vanilla pastry cream 2/3." Why isn't pastry cream recommended? For cremeux, I can guess that its freezability makes it more flexible in commercial kitchens than pastry cream. A wild guess for recommending compote + vanilla pastry cream instead of a pastry cream made from puree is that you lose the richness from the milk, but they also include milk powder for some of the pastry cream recipes.