28 March 2020 | New Scientist | 51PATNOWA/
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MANY amateur cooks, even quite
confident ones, find making pastry
intimidating, but making a good
pie or tart isn’t that hard once you
grasp the basic concepts.
When flour is mixed with water,
proteins in the flour link together
into long strands called gluten that
can make dough springy. With
pastry, unlike bread, the objective
is usually to limit gluten by using
low-protein flour, less water and
little kneading. This helps to create
tender and flaky textures. Any
sugar or acid added to the dough
will also inhibit gluten formation.
The way that fat is incorporated
into the dough plays a big part in
determining the texture of pastry.
In shortcrust pastry, fat is worked
in to coat the flour particles and
stop them from becoming
hydrated. A little water or milk
helps the dough come together,
but the fat inhibits the formation
of a gluten network.
In puff pastry, cold butter is
incorporated into the flour so that
much of it stays in distinct layers,
separating thin layers of dough.
Butter is around 16 per cent water.
In the oven, the water evaporates
quickly, pushing apart layers of
dough and creating a flaky texture.
For both kinds of pastry, you
must be careful not to overwork
the dough, or you will warm the
butter and make it release water.
This will result in excessive gluten
and a chewy, tough result. That is
why pastry chefs use cool marble
worktops and chill their tools.
Vegetable shortening is more
forgiving than butter, but doesn’t
melt in the mouth or taste as good.When it comes to choosing a
recipe, rhubarb tart is one of my
favourites. In the UK, rhubarb
season begins in April, but before
then you can buy forced rhubarb.
These plants are kept in the dark,
making their stems grow quickly
in search of light. This gives them
a sweet taste and a rich red colour.
To make the shortcrust pastry
for the tart, mix the flour, icing
sugar and a pinch of salt. Cut the
butter into cubes and rub it into
the mixture with your fingertips
until it resembles breadcrumbs.
Add just enough milk to form
the dough into a ball, wrap it in
plastic and chill it for an hour.
Grease a 26-centimetre tart
case. On a floured surface, roll
the dough into a circle that isabout 3 millimetres thick, then
press it into the case and poke
holes all over the base with a fork.
Place a piece of greaseproof paper
on the pastry and fill the case with
baking beans or uncooked rice to
stop the pastry base from rising.
Bake for 15 minutes at 180°C, then
another 15 minutes without the
paper and beans.
Cut the rhubarb into pieces
4 centimetres long. Toss with 75g
of sugar and leave for an hour to
absorb sugar and release moisture.
For the filling, mix the butter and
125g of sugar, then mix in two eggs
and 125g of ground almonds.
Spread this into the pastry case,
then press the rhubarb pieces into
the filling, arranged artfully. Bake
for 35 minutes at 180°C. ❚Master the principles of a perfect pie dough and you will
never again feel worried about making it, says Sam WongPuzzles
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and the quiz p52Feedback
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for New Scientist
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on the world p53Sam Wong is social media
editor at New Scientist.
Follow him @samwong1Science of cooking Week 13
Become a pastry whizz
Science of cooking online
All projects are posted at
newscientist.com/cooking Email: [email protected]What you need
Pastry:
250g plain flour
125g cold butter
25g icing sugar
3 tbsp milk
salt
Filling:
400g rhubarb
200g caster sugar
75g butter
2 eggs
125g ground almonds
Next week
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