Making a pastry that beats or rivals that of a pastry shop isn’t something that happens to me very often. I mean, a good cookie or muffin are doable, but those more delicate, often French, pastries, aren’t as easy.
But, this caramel nut tart exceeded all expectations. It’s made by following a recipe from Bouchon bakery and truly brought me back to a French patisserie. Delicious and not even that hard to make, once you understand what you’re doing.
Sweet vs savoury pastry tart shells
When you’re making tarts you will generally use some sort of a tart shell. Within French pastry there are of course a ton of recipes, but for this tart we’ll look at one main aspect: choosing to use a savoury vs. a sweet tart shell.
In French pastry these two pastry styles are called pâte sucrée and pâte brisée. The pâte sucrée is the sweet version, the other is a savoury pastry dough without any sugar in it.
If you’re making a tart with a very sweet filling you want to limit the overall sweetness by using the savoury dough. On the other hand, if your filling isn’t as sweet you could consider using a sweeter pastry to balance out the flavours.
Balancing these flavours is what distinguishes a good from a brilliant pastry chef. I’m definitely not at that level, but can learn from the experts! In this caramel nut tart we’re using a savoury tart dough since the filling, with the caramel, is pretty sweet by itself.
Making a caramel sauce
So we’ve got a savoury pie crust, and we want to add a sweet, flavourful topping. A caramel works great for that, especially since the nuts in this tart aren’t sweet, but have a great depth of flavour. Caramels get that great flavour thanks to the series of chemical reactions called caramelization.
We’ve discussed how to make a caramel before and how to fix it. As long as you don’t burn it, it can just about always be fixed! Crystallization? Add some water and start over. Cooked it to too little moisture? Add water and cook to the right temperature.
Caramel sauce consistency
For a tart like this the main challenge sits in creating a caramel sauce that is just the right consistency. It should be thin enough to seep through the whole pie, soft enough so you don’t break your teeth biting it (the tart shell should be more crispy than the caramel), but firm enough so it doesn’t pour out as soon as you cut into the tart.
The higher the temperature of your caramel, the thicker and firmer it becomes. If you stick with just sugar and water, you can use a thermometer to determine the consistency of your final syrup (as we discussed in greater detail here). The less water and thus the more sugar, the higher the boiling point and the less runny and firmer the final product.
Enriching the sauce with butter & cream
Once you’ve caramelized your sugar, you can enrich a caramel sauce by adding cream and butter. They both contain a lot of fat, which will make the sauce more creamy and richer. Since they also contain proteins, they will also enrich the flavour and colour because of the reactions between the proteins and the sugar in the caramel, the Maillard reaction.
Caramel nut tart recipe
Bringing all the science and understanding together gives us a wonderful caramel nut tart: a savoury tart shell, filled with roasted nuts and a deliciously sweet and just firm enough caramel filling.
- 185g of nuts (e.g. a mixture of pistachio, almonds, cashew and hazelnut; see notes)
- 305g all purpose flour (split into two equal portions)
- 1/4 tsp salt
- 225g butter (cold, cut into pieces)
- 60g cold water (the colder, the better, as long as it isn't frozen)
- 85g corn syrup (white)
- 125g sugar
- 100ml water*
- 20g butter (unsalted)
- 100g whipping cream (high fat-%)
- 15g whipping cream (2nd addition)**
- If you're using unroasted nuts you have to roast them. Place the nuts on a baking tray in a pre-heated oven (180C) and roast for approx. 10-15 minutes. Keep a close eye on them so you can pull them out when they've got a nice light brown colour and aren't burned yet.
Tart shell (pate brisee)
- Place half the flour into a food processor and add the chunks of butter. Process until you see no separate pieces of butter anymore.
- Add the rest of the flour and mix until it's all just combined, as short as possible.
- Add the water to the processor and mix for only a few seconds, until it has just combined. You want to make sure you mix as short as you can to prevent developing the gluten and melting the butter (read more here).
- Take the dough from the processor and form it into a ball, wrap it in plastic wrap or put it in a plastic bag and place it in the fridge for at least 30 minutes (you want the butter to get cold again and the dough to firm up; you could also leave it in overnight if you want to).
- Take the dough from the fridge and sprinkle a working surface with some flour.
- Roll out the dough until it is a few mm thick and is large enough for your baking tin (we use a low one with a diameter of approx. 20cm.
- Place the dough in the tart tin, cover with parchment paper and pour in dried lentils (or beans or rice). Leave to cool down in the fridge again for another 30 minutes.
- Bake in a pre-heated oven at 160C for approx. 40 minutes. Take out the parchment paper and the lentils. It should now be firm enough to hold its shape put still pretty light in colour. Bake for another 20 minutes (or until it is a nice golden brown).
- Cool on a cooling rack (here's why, it makes them more crispy).
- Add the glucose, sugar and water to a pan on a medium/high heat. Heat up the mixture and ensure the sugar dissolves well in the water. Once it's all dissolved try to not stir it, or very little. Bring the mixture to the boil and keep on cooking until it starts turning brown. Keep a very close eye on it at this point, you don't want it to burn, but you do want to create a nice peanut butter colour. If you've got a thermometer, you want to boil it up to 175-179C.
- Once it's reached the desired colour and temperature,turn down the heat and add all the butter. Take care, it might splatter and stir it through quickly.
- Pour in the cream once the butter is dissolved. Again, take care, it will bubble vigorously and rise up in the pan quite a bit.
- By adding the cream and the butter you've cooled down the sugar mixture. Bring it back to a boil and cook it to 120C. Take it from the heat and add the remainder of the cream.
- Use immediately.
This really is the easy bit. Take the cooled down shell and place the nuts inside. Make sure there aren't a lot of empty spaces and that the nuts aren't stacked on top of one another too much. Ideally, you have a single layer of nuts. Pour over the warm caramel jam (once it's cooled down completely it will have thickened too much to seep through all the nuts).
Nuts: use nuts you like, we used approx. 80g cashews, 60g almonds and 35g hazelnuts. We left the skin on the almonds and hazelnuts, but you can also use those without the skins. Take care to use unsalted nuts!
* You don't need to be very exact with the amount of water. You could even leave the water out, however, that is a lot harder since the sugar will burn to the bottom of the pan more easily. By adding extra water you help the sugar dissolve. Once you start boiling the sugar mixture, the water will boil off again. The more water you add, the longer it takes to boil of the water and turn brown, there really aren't other negative consequences for this recipe.
** This cream is used to finetune the consistency of the sauce. If you find that your sauce is too runny (take care to cool it down completely before judging the consistency since the sauce will always be more runny when it is warm), add less or none of this additional cream next time (you can make it less runny by reheating the sauce and cooking it to 118-120C (depending on the desired consistency). If the sauce is too thick, re-heat it slightly and mix in some additional cream (in 10-20ml increments).