We had our sights firmly set on the Bohemien one, though (hey, free chocolates, who could turn that down?) and on the day, after having our delicious lunch from the stalls outside we located the Moore Wilson Chat room and nabbed front row seats (actually there were only three rows, each class was limited to 20 so we couldn't have been too far away). Jiri, or George, as he introduced himself, is the man behind Bohemien, and told us how he became fascinated with chocolate, due to its very precise chemistry
Our little package of chocolates was on our seat when we arrived so of course by this stage I had already scoffed one. They are what he calls his 'Seventy' truffles (hmm, just realised I didn't take any photos of these, I guess I was more focussed on the eating), so called because they are made with 70% cocoa solid chocolate. He uses Callebaut chocolate for all his truffles. I love Callebaut chocolate. Mr Cake hates this fact because it comes in 2.5kg bags which cost about $60 from Moore Wilson's. 2.5kg is quite a lot of chocolate... But somehow not enough to last very long in my kitchen. Hmm...
George explains that today we'll cover the two techniques used in making these truffles - tempering chocolate (yay, I've been wanting to learn this properly for ages) and making ganache. To start with he melts the chocolate to temper, and explains as it needs to cool a lot he'll set this aside, then we'll do the ganache.
I thought I wouldn't learn much from this part of the class, as I have made ganache dozens of times and thought I had it down pat. Turns out that those occasional failures are all easily explained away, and a large part of my technique was pretty wrong. Oops!
He explains that the cream should only just come to the boil, then add the chocolate and gently fold through. As soon as about half the chocolate is melted take it out of the pot to reduce the heat being applied to the chocolate, and continue to gently stir until the chocolate is melted. The ganache shouldn't ever get hotter than 34 degrees C.
This ganache is destined to be dipped in chocolate to make truffles so you then either pour or spoon the ganache onto a tray lined with baking paper, depending on whether you want to cut it into squares or roll it into balls.This should then be left to set at room temperature - not in the fridge - and takes quite a while so it's preferable to do this step the day before you dip the chocolates.
George is very enthusiastic and energetic and explains to us the molecular structure chocolate has, depending on the temperatures and conditions it sets in. He tells us that the fats in cocoa butter have a polymorphous crystallisation process, and can form 6 different types of molecule. Depending which of these form the resulting chocolate has different attributes - but only one of them gives the smooth, glossy finish and satisfying snap that makes chocolate magical.
We got the recipe for the truffles and a guide to chocolate when we came in, and included in this is a graph showing the "pre-crystallisation curve", which shows the temperatures needed to properly temper the chocolate. Essentially tempering involves heating the chocolate to 45 degrees (for dark chocolate), cooling it to 27 degrees, then warming it to 32 degrees. However, it's not as simple as it sounds!
The initial heating isn't so hard, but once it has cooled to about 34 degrees constant stirring is required to encourage the correct type of crystals to form. There's a lot of stirring going on in this class!
George shows us his fan, which he uses to aid the cooling, stirring all the while. I can see why this is an essential tool, as it takes quite a while even with the little fan trained on the bowl. Eventually his jazzy little instant-read thermometer (I want one!) tells him his chocolate has reached the correct temperature, and then he whips out the next toy - his heat gun. He recommends this over a more concentrated heat as it's more controlled. He tells us we can use our hairdryers but he burnt his out doing too much chocolate so went for the gruntier heat gun. It shouldn't be too hot - he demonstrates holding his hand in front of it - and gently does it as far as warming the chocolate goes - a degree too hot and you can destroy all those carefully created molecules!
Of course, even as you warm you have to keep stirring. Stir, stir, stir... So you might have to come up with some creative ways of holding your tools. ;-)
Once the chocolate is ready he tests it to make sure - he drops some onto a piece of baking paper, and lets it set for five minutes. If it sets without streaking and is nice and shiny it's good to go.
He has some pre-made ganache, though it's a little too soft as the room is quite warm so rolling it doesn't work too well. However, he uses gloved hands to make the blobs into balls, then lets them sit to form a thin crust before dipping into the chocolate. We are told that as we are working with the chocolate we can warm it slightly again, so long as it stays between about 32 and 34 degrees.
He has a box of chocolate shavings, which he rolls the dipped truffles in to give them a textured finish. He tells us if we ever want some of these we can ring him and he'll sell us a box. That's what I've been doing wrong all these years, trying and failing to make my own chocolate curls! ;-)
He also quickly shows us how easy it is to make molded chocolates using a silicon mold and nuts - he drops a couple of almonds into each case and spoons chocolate on top. It takes hardly any time for the chocolate to set and then he pops them out. We also learnt that you can re-temper - even if you messed up and your chocolate has formed the wrong sort of crystals you can start over.
It was an awesome workshop and I learnt tons - and you can be sure there will be some chocolate posts here in the near future! (and even Mr Cake was fascinated - for all he complains about the places I drag him I think he loves it really)