PROSPHORA MADE WITH YEAST
The traditional method for rising prosphora is with starter (prozymi or sourdough starter). In my experience, that method makes the most beautiful prosphora.
However with some experimentation, I have managed to determine the proportions needed to achieve good results using the quicker, easier method of rising the dough using commercial, dried granulated yeast.
HERE'S THE VIDEO - PROSPHORA ON YEAST
FLOUR - preferably organic white plain or bakers flour (I use half and half). Since yeast will be rising the dough, the issues with the flour's protein content are less important than with starter. However I recommend you keepvariables constant. Use the same flour till you become familiar with it.
COMMERCIAL DRIED GRANULATED YEAST
SPRING WATER (Tap water contains chlorine. Again, this has less impact using yeast since it's so vigorous, but may cause issues).
VERY SIMPLE PROPORTIONS
For the weight of your flour, use exactly half that weight in water. (Remember 1ml = 1gram)
For every 500 grams of flour use 1/4 teaspoon of granulated yeast. (This is so light that I don't have accurate scales for such a small quantity. I rely on using the same metal spoon tool set (see image)
For every 100 grams of flour, use 1 gram of cooking salt
To make a 7 inch (18cms) diameter prosphoro I use 600 grams flour, with 300 grams (mls) water, 6 grams of salt, and 1/4 teaspoon of dried yeast granules. I know that according to the proportions for the yeast, it should be a little more than a 1/4 tsp since it's 600gr flour not 500gr, however the problem with yeast compared to sourdough is that it rises too fast and may destroy the seal impression. So I err towards a little less.
Apart from the yeast, every other aspect of the preparation of the prosphoro is exactly the same. Refer to the make & bake page.
After setting up in the same way as outlined for sourdough prosphora...everything clean, with a prayerful mindset (i.e. praying), measure out the flour into the mixing bowl, sprinkle in the salt and the yeast. Don't bother with diluting the dried yeast in water first.
Then spend a minute thoroughly mixing these dry ingredients with your mixing spoon.
Make a cross shaped depression in the flour and pour in the water, holding back about 10 mls.
Mixing is the same as for sourdough.
Once a cohesive mass of dough is formed and all the dry flour incorporated, assess the hydration of the dough.
If it is so dry that you struggle to incorporate the last of the flour, add the remaing 10 mls of water and mix it in. If the dough already feels quite soft and supple, or worse, is sticky then don't add the last 10 mls. (If the dough is sticky at this early stage, the type of flour you have needs less water - so, in future adjust accordingly). I have experimented with different flours and for every variety, exactly half the weight of flour was the right amount of water.
During the 20 minute Autolysis (rest), cover the mixing bowl with a damp tea towel to prevent the surface of the dough from drying.
Knead for 5-7 minutes then rest the dough another 10 minutes under cover.
Knead for another 5 minutes then rest it again another 10 minutes.
Roll and fold, shape and prepare for stamping as per the sourdough method.
The stamped and pierced prosphoro will look identical to the sourdough prosphoro at this stage.
Compared to the traditional method, the rise will surprise you.
In my kitchen at 24 - 26 degrees Celsius, it takes only 3 hours for the dough to rise to the proper level. In similar conditions, it takes the sourdough-risen loaves almost 8 hours.
( Remember the key signs of a proper amount of rise are 1). a doubling in height and hopefully also 2). for the seal impression to have risen at least a few millimeters (1/4 inch) higher than the surrounding dough)
Baking is also the same as for the sourdough prosphora. Remember that everyone's kitchen and oven is different and what works for me may not work for you. Keep notes on each aspect of the process. If anything goes wrong, you then have a chance of varying one factor at a time till you get it right.
In my modern (Bosch) electric oven on the fan-forced setting, it takes 1 hour at 180degrees C, from cold to bake well. (i.e. I place the prosphora in a cold oven then turn the oven on)