Sunday, February 14, 2016

Chocolate espresso dacqoise (gluten free), and science of egg whites!


Valentine's Day Menu
Lots of things are happening. My rank list is in. Tyler and I are going to Peru this week with a tenuous plan at best. Formation came out and I loved it. Hillary Clinton is running for president and is BOSS. Oh yeah, and I finished my last clinical rotation in medical school. It's weird -- it's almost like yesterday when I stepped on the wards for the first time, with a clean white coat (it's an odd shade of yellow-brown-white now), a stethoscope around my neck (which has since been replaced after losing it), and a pocket full of snacks and books (still there). I started on the Heart Failure service on my medicine clerkship with my "cohort" for the clerkship being Dave Cholok, Jason Kung, and Kira Masco, people I had never really talked to much or thought about much before the start of third year. My first presentation was...not good...and I spent at least 45 minutes preparing it. And now my next patient presentation will probably be as an intern, hopefully a little better than it was two years ago.

We'll see.

Look at all those layers!
Anyways, I made a dacqoise for valentines dinner! It's a french dessert made with almond and hazelnut meringue that seems super complicated to make, but it's really not. I made it, I know the pitfalls, now I can share them with you! And realistically...my future self. Anyways. It's simple. It's meringue, buttercream, and ganache. It just takes a full day mostly because you have to rest it and allow it to soften. Then at the end of the day, or the next day, you have a delicious, delicious cake. Arguably the best cake I've ever had.

Some science: Beating eggs

What is Cream of Tartar? 
It's an acid. It is the salt of tartaric acid. There are a few definitions for an acid two of which are that acids can be a proton donor, or an electron acceptor -- but this is a little too detailed to matter right now. What you need to know is that tartaric acid has a bunch of protons in it (or that it can accept a lot of electrons).

What happens when you beat eggs? 
You agitate it with a whisk enough that you (A) incorporate air bubbles that have water on their surface and (B) denature the proteins, meaning you make then go from gooped up blobs to unraveled. The proteins, since they are made up of a bunch of different atoms, start attaching to each other. Particularly, the sulfur ions that help stabilize the structure of the proteins start attaching to each other. These bonds surround some of the air bubbles, and "squeeze" the water off the surface of the air bubbles. This is why when you whisk egg whites sometimes you get that pool of water at the bottom if you let them sit for a minute.

What's the point of adding Cream of Tartar to egg white when you beat them? 

They "stabilize" the proteins. What that means is that the acid (protons) in the Tartaric acid bind to the sulfur ions and prevent them from bonding too tightly and keep them in an "open" loose formation. They keeps the water in the meringue for the most part and keeps your egg whites from deflating.

What does this mean?

This means that you can add any acid and achieve similar results! Lemon juice, etc. The upside to the tartaric acid is that (A) you don't add liquid volume and (B) you don't impart (much) flavor other than the tang of the acid if you add too much...which I've done before.

So wait...it doesn't increase the volume of the egg white?

Nope, beating it just does that, cream of tartar just stabilizes the proteins by donating a protein (or accepting electrons!). Another thing you can do to make your egg white beating go faster is not add sugar at the beginning.  This is because sugar attracts water (hygroscopic) and the crystals can get in the way of the egg proteins unravelling and finding each other. So if you add the sugar part way through, it can help keep the water in, and won't slow down your egg white beating.

Whew, now that we're done with the science...on to the delicious!

Chocolate-espresso dacquoise
Modified from Treats-SF

My advice when starting this --

  • read the directions for each component first and get your mise en place (ingredients ready to go). 
  • Actually put everything in the fridge for the resting times. 
  • Really make sure your meringue has a smooth top when you put it in the oven, it really makes life so much easier when you are putting the whole thing together later. For reals. FOR REALS. 
  • All components can be made ahead of time up to two days. Even the whole cake can be made a whole day ahead of time. 
Meringue

  • 4 egg whites (save the yellows, you need them for the buttercream) 
  • 3/4 cup almond meal
  • 1/2 cup hazelnuts, toasted
  • 3/4 cup plain white sugar
  • 1/4 tsp cream of tartar
  • 1 tablespoon cornstarch
  • 1/8 tsp salt 
Preheat oven to 250F 

Line a baking sheet with wax paper. Measure out a rectangle of 10x13inches and draw it in with a pencil. Then place the pencil side down on the baking sheet. This is important because it'll let you make a perfect rectangle, which will help with the dacquoise. You can get your parchment paper to stick by spraying the bottom of your baking sheet and then putting the parchment paper down.  

In a food processor, pulse 1/2 the sugar, all the hazelnuts, almond meal, cornstarch, and salt together into a fine texture. In the bowl of stand mixer, put the eggwhites and cream of tartar in the bowl, put it on low-medium and with whisk attachment, and whisk until foamy. Then turn up the speed to medium-high and slowly add the other half of the sugar. Keep beating until stiff peaks form. It took me 4-5 minutes. Then fold in the almond meal-hazelnut mixture in two batches. 

Spread it evenly on the parchment paper and make sure the top is as level as you can get it. Trust me, I didn't, and this step is important. 

Pop it in the oven for an hour and a half. Then turn the oven off without opening it (you don't want the heat to escape) and keep it in the oven for another hour to hour and a half to harden. Then pull it out and let it cool. 



German Buttercream 

  • 4 egg yolks
  • 2 tbsp sugar
  • 3/4 cup whole milk
  • 1.5 tsp corn starch 
  • 1/4 tsp salt
  • 2 sticks butter (16 tbsp) 
  • 2 tbsp amaretto mixed with 1.5 tbsp instant espresso or coffee
Basically a german buttercream is a pastry cream mixed with butter. It gives it a creamier texture. So you make the pastry cream first. Mix the egg yolks, sugar, and cornstarch in a medium heat proof bowl. In the small saucepan, heat up the milk until it's simmering, turn off. Then, while constantly whisking slowly mix half the milk into the egg yolk mixture. This tempers the egg yolks and prevents them from scrambling which is what would happen if you added them in right away. Then pour the whole shebang back into the saucepan and turn it back on, whisking constantly until it's thick like pudding.

Put it in the fridge for 30 minutes to an hour to cool down. 

After 30 min, in a stand mixer with a paddle attachment beat the room temperature butter. In three separate batches add in the pastry cream, scraping down the sides to make sure everything is well incorporated. Then add in the amaretto-coffee mixture. Turn it up to high and beat the crap out of that butter until it increases in volume and starts to look like a butter cream. 

You can store that covered in the fridge.


Ganache 

  • 6 oz bittersweet or dark chocolate
  • 3/4 cup heavy whipping cream 
  • 2 tsp corn syrup
Put the chocolate in a heat proof bowl. Heat up the heavy whipping cream and the corn syrup in a small saucepan until simmering. Pour over chocolate, and whisk it to incorporate. Donnnne. That step is easy. Oh yeah, and let it chill in the fridge for about 10-15 minutes until it's still liquid, but not hot. 

Okay, so with the meringue, cut it down with a serrated knife so it's 10 x 12 inches. You want to do this slowly, so you're using the weight of the knife to cut it. Then, make a mark/nick in the meringue to divide it into four equal parts. These will be your layers. Cut them length-wise gently. If it breaks...oh yeah, you can glue that back together with the butter cream/ganache, but try to keep them in one piece. 

Then lay them out on a baking sheet. Put 1/4 cup chocolate ganache on three out of four layers. spread it, save the remaining chocolate. Put it in the fridge for 20 minutes. Then pull it out, and but 1/2 cup of the buttercream on the layer that does not have chocolate. Then place the buttercream side down on top of a chocolate layer, so the buttercream and the chocolate are touching, and you're making a meringue-chocolate-buttercream-meringue sandwich. Then put more buttercream on the top of the sandwich (another 1/2 cup) and put a chocolate piece on top of that, adding to the sandwich. 

By the end of it, you should have a clean (no chocolate,no ganache) top, and a four layer sandwich going on. Then you want to coat the outside in whatever buttercream you have left. The most important part is the top, the sides can be coated kind of mehhh...but the top should be smooth and flat. 

Then refrigerate it for half an hour to an hour. I skipped this step, and boy did I pay for it. My stuff still turned out tasting amazing, but I mean, it was defffinitely not as pretty as it could have been. When you're about to pull out the dacquoise, pop the remaining chocolate in the microwave for 10 seconds to melt it so it's pourable but not hot. 

Pull out the dacquoise. Pour the chocolate on top, and quickly spread it over the top into a smooth layer. Then spread the chocolate that dripped on the sides. 

Almost done...

Topping


  • Hazelnuts
  • Toasted slivered almonds
Then you want to coat the side of the dacquoise in almond. You can do it with it sitting on a tray, or you can lift it up if you're so bold (I did, it's no big). Just press the almonds into the side. 

Then use the hazelnuts on top. You can line them up in a row to "mark" the pieces so it is easier to eyeball pieces when you cut. I put the slivered almond on the entire dacquoise because I wanted to...but you don't have to. 

Then refrigerate for hour or two before slicing. Or you can let it sit over night. Stays good for 2-4 days covered in the fridge. 

Best. cake. ever.