Quark Tart

For many years, Frieda, my mother, used to make the lemon version of this recipe on a regular basis. It is surprisingly light, and great in summer. I did make some small changes to the crust and the filling, and also came up with a raspberry and a lemon-lime version.

"Quark" is not only the name of a character in the science-fiction TV series Star Trek - Deep space Nine, and the name of a sub-atomic particle. It is a traditional light, soft, creamy, low-fat, fresh-cheese that is readily available throughout northwestern and eastern Europe. So, quark is not generally available in France (and the rest of "latin Europe"), but faisselle cheese is a perfect substitute (use 6% fat - not fat-free, not the goat milk variety, and not fromage frais) .

Quark is made by straining soured milk that has been warmed to the point of coagulation (so it is actually very easy to make at home overnight). This process dates back several thousand years. In a pinch, you can try and whip up a 50/50 mix of thick yogurt and cottage cheese.

Preparation + cleaning time: 1 hour
Bake time: 40 minutes
Chill time: 2 hours
Makes 12-16 servings
Best when made 1 day ahead

INGREDIENTS

Ingredients for the pâte sablée dough:
200 grams pastry flour (D: type 405 , F: type 45)
If you want to make it really nice: use only 150 grams of flour, and add 50 grams ground almonds, or coarsely ground candied hazelnuts ("pralin"), and 3 tablespoons finely grated, sweetened coconut
150 grams unsalted butter, at room temperature, cut into pieces
50 grams brown sugar or dark brown sugar (5-10% molasses).
In France, use "sucre complet" or "sucre intégral"; second choice: "cassonade" ( = sucre roux de canne) or "vergeoise" ( = sucre roux de betterave)
pinch of salt

Ingredients for lemon filling:
200 grams fine crystal sugar
3 eggs, separated into 3 yolks and 2 whites plus 1 white
500 grams quark
13 grams gelatin
This is 7 sheets of a standard 9-sheet/17 grams package
250 ml (1/4 liter, 1 cup) heavy whipping cream (do not use "light" cream)
150 ml (5 fl. oz = 10 tablespoons) lemon juice (about 3 large lemons)
Optionally: if pressing juice from (untreated) lemons, you can get the zest of one lemon and add it to the juice

Ingredients for lemon-lime filling:
200 grams fine crystal sugar
3 eggs, separated into 3 yolks and 2 whites plus 1 white
500 grams quark
13 grams gelatin
This is 7 sheets of a standard 9-sheet/17 grams package
150 ml (3/4 cup) lemon juice (about 3 large lemons)
250 ml (1/4 liter, 1 cup) heavy whipping cream (do not use "light" cream)
150 ml (5 fl. oz = 10 tablespoons) lemon and lime juice, e.g.:
Mostly lemon: 100 ml lemon juice + 50 ml lime juice
50/50: 75 ml lemon juice + 75 ml lime juice
100% lime: 150 ml lime juice (may need some extra sugar, unless you like the tartness of lime juice)
100% Key Lime: 150 ml Key Lime juice

Ingredients for raspberry filling:
200 grams fine crystal sugar
3 eggs, separated into 3 yolks and 2 whites plus 1 white
500 grams quark
22 grams gelatin
This is 11 sheets of a standard 9-sheet/17 grams package
500 grams fresh raspberries (or thawed-out frozen raspberries), made into a coulis by passing it 5 seconds in a blender or food processor
I use frozen raspberry pieces - available all year around, and much cheaper than fresh whole raspberries
30 ml ( 2 tablespoons) lemon juice
250 ml (1/4 liter, 1 cup) heavy whipping cream (do not use "light" cream)

EQUIPMENT & SUPPLIES

Springform pan (F: moule à manqué), diameter 24 cm (9 or 10 inch)
Alternatively: one springform pan with a diameter of 18 cm (7 inch) and two of 10 cm (4 inch)
If using making raspberry filling: blender or food processor
Medium size bowl
Small bowl
Large bowl
Small sauce pan (for dissolving the gelatin)
Plastic spatula
Hand-mixer
Plastic kitchen film (cling wrap)

PREPARATION / DIRECTIONS

Instructions for the crust:
In the medium size bowl, mix the flour, sugar, salt, and butter
Knead into a smooth dough
If you want, use a kitchen machine with a dough hook; run at high speed until smooth, or until one big lump has formed.
Pre-heat the oven to 175 °C (350 °F)
Cover the bottom of the pan evenly with the dough
Do not make the bottom thicker than about 5-6 mm (1/4 inch, about the height of ridge at the bottom of the springform ring that hold the bottom of the springform); you probably will not need all of the dough!
Prick the dough with a fork
Bake the crust for 40 minutes at the center of oven
Note: in a mechanical convection oven (i.e., with fan), use lower temperature setting (e.g., 150 °C)
Remove from the oven and let cool - leave the crust in the pan

Dough in the springform pan - ready for baking

Instructions for the filling:
In a large bowl, mix sugar, egg yolks, one egg white, quark, and lemon juice (or lemon/lime juice or raspberry coulis)
Soak the gelatin sheets in cold water for about 10 minutes
I usually cut the sheets in half with a pair of scissors
Bring 6 tablespoons of water close to a boil, then take off the heat
As soon as small bubbles begin to form on the bottom of the pan, the water is hot enough!
Squeeze the cold water out of the gelatin and dissolve the gelatin in the hot water
Make sure the gelatin is fully dissolved by stirring with a spoon, or by simply swirling the sauce pan
Let the dissolved gelatin cool for at about 5 minutes
Blend the gelatin in with the quark mix (use a spatula to get all of the gelatin out of the pan), then beat with a hand-mixer at high speed for about 3 minutes
Careful - it will splash! Put a splash guard on the edge of the bowl, if you have one.
Whip the heavy cream for 2-3 minutes
Whip the remaining egg white for 1-2 minutes
With a spatula, fold the whipped cream and the beaten egg white into the quark mix, then blend with the hand-mixer at low speed for about 10 sec. Do not over-beat!
Pour the quark mix onto the crust in the springform pan
Put plastic kitchen wrap across the top of the springform pan
Chill in the refrigerator for at least two hours

Lemon quark tart - going fast!

Marbleized lemon-raspberry quark tart

Small lemon and raspberry quark tarts

(yes, the crust is too thick)

Using a smaller springform and two small loaf pans

SERVING & GARNISH SUGGESTIONS

Keep refrigerated until about 10 minutes before serving
The filling will stick to the wall of the springform pan. Before un-clipping and removing the wall of the pan, run a paring knife flat against the inside of the wall, and go all the way around.

NOTES

The crust can be made and baked a day ahead.