Science Interviews


Mon, 27th Jun 2016

Chocolate emulsions for dessert

Adam Geileskey, Hotel Chocolat

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The best course of any meal? Dessert! To find out a bit about the physics of Chocolatechocolate emulsions, and how to make the perfect ganache, Georgia Mills invited Adam Geileskey, Head of Chocolate Development at Hotel Chocolat for a 'ganache-off'...

Adam - Okay Georgia, so weíve got a couple of things on the go at the same time. Weíve got some chocolate melting. Iíve got some orange juice which is actually Sicilian blood orange warming up and Iíve got some cream warming up and weíre trying to get all of these to the same temperature, about 45 degrees centigrade. So as we know chocolate is sold at room temperature, and then as we warm it up to 45 degrees, it goes a lovely liquid, and what weíre going to do is how we can combine these ingredients together to make some interesting desserts and maybe even chocolates.

Georgia - So whatís the name of the dessert weíre making?

Adam - Okay what we're going to do is have a go at making a ganache. A ganache is when you add chocolate and some kind of liquid. So normally traditionally thatís cream but you can do some interesting stuff and weíre going to try orange juice today but you could easily do this rum, tea and, in fact, any kind of liquid you can think of we could have a go at making this.

So the science of this is weíre making an emulsion. An emulsion is a mixture of two immiscible liquids, so in this case weíve got cocoa butter, which is a fat and at 45 degrees itís going to become a liquid, and weíre also adding thereís water in the orange juice and in the cream. And weíre going to be combining both to those, trying to mix it really thoroughly to break the cocoa butter down into tiny little pieces and surround that with a sea of water. Adding the cream and the fruit juice will also give it some extra flavour.

Georgia - So when you say immiscible, you mean they canít mix together?

Adam - Normally no. They canít mix together so if you drop one on top of the other they would separate.

Georgia - Like oil and water, something like that?

Adam - Exactly, like oil and water. And what weíre doing with the ganache is very similar to what you do if ever youíve had a go at making a mayonnaise, or even paint!  The way it works is the cocoa butter will get broken down into such small pieces that itís then held by this sea of water.

Georgia - Great, so weíve got some bowls here.

Adam - Right, so weíve got two bowls. Weíve got the cream and theÖ Youíre going to have a go at the cream and Iím going to have a go at the fruit juice, OK - weíre going to have a ganache off! So Iím just going to now pour some of the melted chocolate into the cream and now Iím going to put some of the melted chocolate into my fruit juice.

Georgia - Chocolate and juice, it just doesnít seem right.

Adam - Itís definitely going to work. Iím going to hand you a spoon. You need to get stirring. Get the spoon right in the bottom and get that moving.

Georgia - Oh gosh! Iím spilling ganache everywhere!

Adam - Itís going everywhere, itís going everywhere! So you can see whatís happening now. To start with it goes really lumpy and whatís happening there is the water lovingÖ youíre doing really well nowÖ the water loving cocoa powder in the chocolate sucking all the water and then the more you mix it the smoother it gets. And what youíre looking for is something thatís really nice and shiny and glossy, which actually, yours is looking better than mine.

Georgia - But on the other hand I have splashed it all over you and Iím very sorry about that.

Adam - Iíll be having that later. OK so, actually, we can stop now. Youíve got a beautifully soft and glossy ganache. Actually, that looks really professional - if youíre looking for another job weíd be happy to talk to you! Would you like to try some of it?

Georgia - I would love to. I was just waiting for you to say.

Adam - I recommend with your one, I recommend try it with a strawberry.

Georgia - Dip the strawberryÖ itís nice and warm.

Adam - While youíre eating that now, you could use this as it is. This is still really nice and warm - itís like 45 degrees and his is perfect for dipping fruit and stuff like that into and just eating as it is or even a cracker or something like that, which Iíve also got. But if you left this and you left it overnight to set up properly, the cocoa butter then starts to crystallise. So it starts to go solid again and that firms the whole mix up and thatís what weíd use for the centre of a filled chocolate, so a nice soft chocolate. If you then took a scoop of that and rolled it in cocoa powder or dipped it in chocolate, youíd have a nice filled chocolate.

Georgia - OK. So as they are now, theyíre kind of just a bit liquid and soft and ohÖ. Youíve got some here you made earlier Blue Peter style.

Adam - Yes, Blue Peter style - so the one Iíd like you to try this is the orange ganache. This is the one that I made that didnít come out as well as yours but it does taste very good.

Georgia - This is on a nice cracker.

Adam - So tell me what you think.

Georgia - ...Oh.

Chris - Can we all try some?

Georgia - MmmÖ thatís fantastic.

Chris - Alex and Sue look like theyíre going to kill someone here if they donít get a chance to try it.

Adam - Hereís some crackers and some chocolate.

Georgia - Well, I stand corrected. The orange juice and chocolate work lovely together. Does this mean itís a bit more healthyÖ Sorry youíre wiping off all the chocolate I sprayed on you earlier. Does this mean itís a bit more healthier than the cream one, the traditional ganache?

Adam - Yes. If you think about chocolate. Half of the chocolate is cocoa butter and the other half itís a mixture of milk powder and sugar. So, obviously, adding water into that dilutes the energy parts of the ingredients so, if you were using a fruit juice, that then reduces the amount of fat in the chocolate.  But then, if you were making this say with a tea, so maybe something really interesting like a matcha tea or an earl grey tea, youíre just adding really water and flavour and that would do an even better job in terms of reducing the calorie count in that filled chocolate.

Georgia - I canít wait to experiment with all the different liquids. And so, just to summarise, itís basically as simple as melting the chocolate to 40 degrees, mixing it in with the liquid of choice and then leaving it to set in the fridge or just eating it all immediately with strawberries, as I tend to do with these ones.

Adam - Yes, pretty much. So the important thing is melt you chocolate, Iíd melt it to just over 45 degrees, make sure you combine all your ingredients at the same temperature. Imagine if you add cold cream to warm chocolate it just sets the chocolate and makes your grenache go really lumpy, and then get on and mix those as fast as you can, and then just sit back and enjoy it. The advantage of this as a dip at the dinner table is that it takes a lot longer for it to set so you can enjoy it for longer.

Georgia - And this is the friend of the chocolatier. You can use this to make fillings for chocolates like those mojito chocolates we were eating naughtily before the show?

Adam - Ah we use all sort of things in this type of recipe, so we add all sorts of alcohol. So I would have a go with gin, I think that would work really really well. We use all sorts of vodkas and then equally we have a recipe with carrots, like carrot cake type recipes. Weíve got some really interesting cocktails like mojitos and then in some of our recipes weíd use real champagne and make things like champagne truffles, so itís really versatile.

Chris - Can I ask you a question though? How do you get the alcohol to stay inside the chocolate without sort of eating itís way out?

Adam - If youíre making a ganache you donít really have a problem with that. What you do is you make your ganache up to this stage and then you add your alcohol. Donít try and hear everything up with your alcohol. Make your ganache first and then add your alcohol into it so it goes in last - it lasts really well. But do keep your ganache... If you are going to have a go a making them keep your grenache in the fridge because this is a really simple recipe and it needs to be kept refrigerated otherwise it will eventually go off, and it lasts for a few day.

Chris - What do you think Will?

Will - It looks, and sounds, and tastes delicious. Iím a fan!

Chris - Youíre tucking in Sue.

Sue - Oh yes. Iíve just tried a little bit and itís perfect!

Chris - Youíll be going back for more. Alex - is that something you could serve up in the restaurant?

Alex - Yeah, I think itís a great idea. We make all our own petit fours and chocolate truffles to go out with coffees at the end of a meal and I think this is a great addition to it.


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