Secret to solar cooking puff pastry or flaky pastry, short crust pastry.

Solar cooking has the same problem as microwave cooking, soggy pastry.
Every time....

Here is a simple low tech solution for solar cooks using any solar oven
or in this low tech example 2 borosilicate glass trays held together with paper clips.

What you need:
Solar oven or

2 Borosilicate baking trays held together with paper clips

on a aluminium tray or reflective foil

metal baking tray
baking paper
coconut fibre
pastry

Step 1: The Secret Is to Clear Lid Condensation Inside the Solar Oven

All pastry gives off steam while cooking.
The steam condenses on the lid and walls of the solar oven.
It needs to drain off at an angle of at least 10 degrees.
Many commercial solar ovens have a lid angled at 10 degrees or more.

In this example the clipped together borosiliacate baking trays are angled at about 15 degrees
so that the condensation on the lid and sides rolls down to the lowest edge internally.
Some steam will escape from this set up because the glass trays are never even...

The base of the bottom tray has an inch of coconut fibre in it all the way to the sides.
4 glass marbles, larger ones on the lower side, are included to provide a stand for the metal baking tray.
It is necessary for the metal baking tray to be in the least amount of contact with the glass walls and base to reduce direct heat loss.

Coconut fibre is extremely hydrophilic. It captures water and holds over 6 times its weight in water.
The coconut fibre captures water from the steam directly, and the condensation on the sides.

Step 2: Solar Cooking in Concentrated Sunlight Mist of Condensation Only

Here is a close up view of the pastry cooking in the baking tray on the bed of coconut fibre.

You may like to consider trying this technique out with the
Cinnamon Sugar Pastry Star Party Snacks recipe here

https://www.instructables.com/id/Cinnamon-Sugar-Pas...

If you are used to solar cooking you will be used to the big drops of condensation, and saying, 'No, no, don't drop on the pizza, don't drop on the middle of the cake'.
The temptation to open the solar oven and wipe down the condensation is usually overwhelming.
This leads to the old saying of 'a watched pot never boils'.
Every time you open a solar oven, you lose much of the heated air inside and the temperature of everything in the oven drops at least 10 degrees.
This means cakes sink, and the cooking time increases....

The coconut fibre is scavenging water droplets and steam, so that the condensation on the lid is reduced, and rarely builds up to a critical mass that drops onto the pastry.
Consequently the cooking time is reduced.
Consequently the pastry has a chance to dry out and puff and brown.
Other dessicants such as silica gel in packets, such as found in pill bottles will do the same thing, and can be used over and over again.
Just dry them out again after baking in the same tray with the lid off.

Step 3: Solar Cooked Pastry Finished No Condensation on Lid

This solar cooked pastry took about an hour.
As you can see from the photo there is no condensation in the lid as the pastry is done.
All the escaping steam from the pastry has been trapped in the coconut fibre.

I was so excited this process actually worked, I forgot to put in the thermometer.
No idea what the temperature got to but has to be above 150 degrees for flour and oil to brown.
This was an experiment so there its just a sheet of pastry without any fillings or decoration.

If you are wanting a professional even chef style brown on the top of puff pastry, use an egg wash.
Egg wash is beaten egg, spread on the pastry with a pastry brush.
That will give the same results of crispy pastry with an even light brown colour on top, for food to be presentable at a function, rather than opening and closing the lid to shuffle pastry items around.

Step 4: SAFETY FIRST BOLLE WELDING SUNGLASSES

Safety first for Solar Cooking

Always wear a pair of Sunglasses for Solar Cooking.
Welding Sunglasses from Bolle are the best in terms of protection
from concentrated solar radiation and heat.
They look like normal sunglasses.
Solar kettle and quick solar cuppa in Instructables here somewhere too

https://www.instructables.com/id/Solar-Kettle-and-Quick-Solar-Cuppa/