Thursday, July 06, 2006

Tart Practice

While I was in Paris I went to Dehillerin, the famous cooking and baking supplies store in Paris. I bought many things, from rings for individual mousses to tart rings to even more silicone molds to disposable pastry bags... (The quaint wrapping gives you an idea of the old-world style of the store, described in detail here).

My goal last weekend was to make a pretty looking tart using the tart rings I bought. I wanted a perfect cylindrical shape to the crust, and a smooth glossy finish to the chocolate filling.

The tart was good, though I think I could still make improvements. The recipe came from the beautiful and mouth-watering Traveller's Lunchbox. The photo shows something that looks luscious yet sophisticated. But mine tasted more like a candy bar. A very good candy bar, with chewy toffee wrapped in crunchy cookie and melting chocolate. Which is a good start, but I'm not a fan of candy bars. I made it twice, as I was invited out two nights in a row. Tart 2 was better than the first, so who knows, perhaps I should try a third time? But my bathing suits are begging me to stop with these experimentations...

The crust
I tried two ways of making the dough, and did not notice a significant difference in texture or flavor: the first, as specified in the Pierre Hermé recipe I used, mixing ingredients with my hands (ugh that was very wet dough, not a pleasant feeling), and letting it rest for four hours before rolling it out on a table sprinkled with flour. Which is hard to do once the dough is very cold.

The second crust I made with the same ingredients, but mixing it the way I would my usual roll-out cookies, which I found much easier: I used my hand-held mixer (whipping butter and sugar together, adding egg, then almonds and flour). I then only chilled it for about 15 minutes and rolled it out between sheets of parchment paper, letting the longer chilling take place at this point. The risk here is rolling the dough too thin, as it is very pliable before chilling. I would be interested to know if this different mixing approach compromises flavor or texture.

Lining the tart ring
I tried a technique for lining the ring inspired from this post, and it worked well: I rolled out the dough quite thin, between two layers of parchment paper and placed the dough in the freezer for a few minutes (as for my cut out cookies). Once the dough was quite stiff and cold I cut it into a circle following the inside contour of my tart ring.

I placed the circle of dough on a parchment paper-lined cookie sheet (do not use a silicone mat, or at least not mine which tends to warp, especially when placed on top of a warped cookie sheet...)

Then I used the ring as a guideline to cut a strip of dough to form the walls of the crust. I placed the ring back around the bottom circle of dough (I discovered it's easier to place the ring on the dough than the dough in the ring), and then very carefully lined the edges with the strip(s) of dough. Notice the vertical seam at the top of this photo of tart 2. I was a bit worried about getting the walls to adhere to the bottom. You can't really push down on the strips without mussing their sharply cut edges. And sharpness of form was what I was after. But I had no leaks. I guess one could brush the edges with egg wash before attaching the sides, but I'm not sure it's nessary with this pâte sucrée.

I then chilled the unbaked crust thoroughly in the fridge, lined it with parchment paper and filled it to the top with rice, and baked it for 15 minutes at 180°C. (You can see on this photo how the warped silicone mat caused the ring to slide up and the dough to squeeze out under the ring, again for tart 2. )

Then I carefully took the rice out and baked the crust for another 10 minutes.

The result
For tart number 1 (photo here), I didn't chill the dough as much as tart 2 and the edges aren't crisp enough. I also somewhat overcooked the crust, thinking as I like a darkly colored cookie I would surely prefer a dark tart crust. But the strong flavor clashed with the chocolate.

Tart 2 is fairly cylindrical, with nice vertical walls that didn't sag (despite the dough peeking out under the bottom of the tart ring). But still, the edges aren't smooth and sharp the way I want them.

Ideas for fixing these problems
- Perhaps I have to chill or freeze the dough even more before forming the crust
- Or else roll the dough a bit thicker
- Or maybe make the walls the the same height as the ring, rather than leaving close to a centimeter sticking up above the ring (I did that to anticipate shrinkage, and to make sure all the filling would fit in the tart)
- Do not to overcook tart crusts or their flavor will compete with the filling.

The filling
Both times I made the tart, the caramel layer was a bit too solid and chewy, making the tart taste like a fancy chocolate bar (Twix?). I believe I cooked the caramel too long both times. The first time because I mistakenly tried for a strong caramel flavor -- not only did it become too hard, but the flavor competed with the chocolate.

The second time I added the cream before the caramel got too dark, but as it had cooled a little it became a somewhat granular. I ended up cooking it longer than necessary after adding the cream to get rid of the grittiness.

This is the second batch of caramel, the one that's the right hue but somewhat grainy. The grains disappeared or weren't noticeable in the final product. For this second tart I added a few walnuts between the caramel and the chocolate layers (more, more, more!). They provided a nice flavor and texture contrast.

The chocolate ganache has to be cooled somewhat before mixing in the butter. But how cool should it be? If the butter isn't fully melted and mixed in it leaves unsightly streaks on the ganache. This is what happened to a small degree with tart 2.

Also, the ganache must be stirred very gently. The first time around I wasn't too careful about this and I trapped a lot of air bubbles in the cream. This doesn't look very attractive (see photo right).

I did a somewhat better job the second time around, though it's hard to tell whether tart 2 has no bubbles or was photographed in more forgiving lighting (I finished making this one at my friend's house, so no time for leisurely photography). Differences in lighting also contribute to making the caramel and chocolate appear more or less dark in the different pictures here.

Another mistake I made with tart number 1 was to let it warm up to room temperature before serving. I would say, in summer weather, serve this tart straight from the fridge, as the ganache is very soft.

Summary of lessons learned regarding the filling
- Don't cook the caramel too long
- Don't let it cool at all before adding the cream
- Add nuts if you are serving to friends who don't count calories (if they do, maybe consider another dessert entirely!)
- Be extra careful mixing the ganache so it doesn't make bubbles. I've read one should keep the spatula in contact with the bowl at all times, and stir slowly...
- Still, make sure the butter is fully mixed in
- Serve tart straight from fridge.

I regret I don't have a good photo of the finished tart. I already feel self-conscious when I whip out my camera to take a picture of a cake just before serving it, so asking friends to wait while I try different lighting conditions is not an option.

Recipe: Chocolate Salted-Caramel Tart
Source: The Traveler's Lunchbox

"Chocolate and Salted Caramel Tart
Serves: 12

For the crust:
2 3/4 cups/350g all-purpose flour
1/2 cup/75g powdered sugar, unsifted
1 stick/125g unsalted butter, cold
pinch salt
2 eggs

For the caramel:
3 tablespoons/50g glucose or corn syrup
1 1/2 cups/275g superfine/caster sugar
2/3 cup/150ml double or heavy cream
3/4 - 1 teaspoon (level) rock salt or coarse sea salt
2 tablespoons/25g unsalted butter, diced

For the ganache:
1 1/2 cups/350ml double or heavy cream
4 tablespoons honey (I used a little more)
10 oz/300g bittersweet chocolate, chopped
1 stick/125g unsalted butter, diced

For the crust, sift together the flour, powdered sugar and salt and cut the butter into chunks. Place in a food processor and process, adding the eggs at the end, until a dough has formed. Roll out the dough into a circle and fit into an 11-inch (29cm) removable bottom tart pan. Chill for at least half an hour. Preheat the oven to 350F/180C. Blind-bake the crust by lining it with baking parchment, filling it with baking beans and baking for about 15-20 minutes. Remove the beans and paper and continue to cook the case for a further 10 minutes or until it is a light golden color. Remove from the oven and leave to cool.

To make the caramel, pour the glucose syrup into a large saucepan and bring it to a boil. Gradually add the sugar, stir and continue to cook until the sugar has started to caramelize and turn golden brown. At the same time, in a separate saucepan, bring the cream and salt to a boil. Remove the caramel from the heat and very carefully add the cream - be careful as the mixture can rise rapidly in the pan. Stir carefully over a low heat with a wooden spoon until smooth. Remove from the heat, add the diced butter, and stir again until smooth. Pour into the cooled crust and refrigerate for 15 minutes.

To make the ganache, bring the cream and honey just to a boil and pour over the chopped chocolate. Let it sit for a minute or two then stir until everything is smooth. Add more honey if it is too bitter. Once the mixture has cooled a little add the butter and stir gently until the mixture is smooth. Pour in an even layer on top of the cooled caramel, return to the refrigerator, and chill for 4-6 hours before eating."

Actually I didn't use the above recipe for the crust. Since I made the crust before knowing what filling to use, I had already made one from Pierre Hermé, which was quite similar though it included almond powder. Hence the specks in my dough, as I used unblanched ground almonds.

An attempt at making a chocolate decoration
I adorned tart 1 with my first tempered-in-a-rush chocolate message, seen in the first photo in this post. Pressed for time, and with daughters getting bored with the DVD they were parked in front of -- a babysitting device used only rarely, I reassure you -- I hurriedly cut a free-form rectangle from a plastic sheet ("papier guitare," which I found at Mora, not Dehillerin, but had to buy 100 sheets at once... expect more experimentation with it!), tried to temper a microscopic quantity of white chocolate, piped a message backwards with no guidelines (backwards as the final result is its mirror image) and chilled it in the fridge. I then tempered another microscopic quantity of dark chocolate, which I spread thinly on the back of the white chocolate text. I chilled it again briefly, placed another plastic sheet on top and chilled it all again before transporting it in the hot humid weather to our friends' house (in time to see France-Brazil). Once there I forgot there were two sheets of plastic, removed the largest one, plonked the chocolate decoration on the tart and wondered why it looked so ugly. Only later did we realize there was still a sheet of plastic embedded in the chocolate text. I removed it (breaking off some edges and smudging the surface of the tart, which I'll admit I touched up later digitally) and voilà, my first chocolate art work. Plenty of room for improvement!

Note: "Allez les Bleus!" is a rally cry to support the French football/soccer team. Sunday is the big day!


valentina said...

I love your blog.Your style, the subjects. Thank you for sharing all these wonderful things with us all.Very inspiring.

Anonymous said...

Only one word Astrid : IN - CRE - DIBLE !!!
Can't believe I have such a multi-talented daughter. Wish you lived closer so I can help you lick your bowls...

Astrid said...

Valentina - Thank you! I enjoyed checking out your blogs too. Wow, in multiple languages, that must take time.

Mom - Thank you for this (unbiased) praise! Hee hee, I remember a time when I was the one licking the bowls around the house. But with my sweet tooth, I had to take over the baking to ensure a plentiful supply of chocolate-covered bowls.

Sam said...

Astrid - your tart is lovely. I have to take some desserts to a party on Saturday and am looking for ideas. Maybe this one is a bit complicated for me? It does sound delcious.

I have put you in my rss reader so i can keep checking on your delicious posts.


Astrid said...

Hi Sam, thanks for dropping by! The only thing slightly difficult (to me at least) is the crust. If you are comfortable blind-baking a crust, then it's really easy. The fillings take no time.

I'm posting a link here to your beautiful pro-France tart, so a) my friends realize I'm not the only nut baking patriotic desserts and b) I remember to try your recipe next time France gets a chance to win a sporting event (sigh, when?).