This recipe yields 10 cups of soufflé. I highly recommend using a gram scale for accurate measurements.
Base for the soufflé:
0,080 kg of egg yolks
0,010 kg of sugar
0,080 kg of ricotta
0,200 kg of lemon juice
0,015 kg of potato starch
Zest of two lemons
Sugar and butter to coat the molds
Egg white mixture:
0,100 kg of the base mixture
0,120 kg of the prepared lemon mix
0,180 kg of egg whites
Pinch of salt
Pinch of cream of tartar
0,050 kg of confectioner’s sugar
Butter all the soufflé molds with melted butter, being careful to do it with vertical movements, aiming the brush from the base to the rim. Place it in the refrigerator. Repeat this procedure when it has cooled well. Coat the mold with sugar afterwards, making sure you tap it upside down to remove all excess. Run your finger around the rim to make sure it is completely clean.
Beat together the egg yolks with the sugar, and when is very well mixed, being pale in color, add the ricotta. Mix it well and place it in the refrigerator.
Dilute the potato starch in some of the lemon juice. Warm the remainder of the lemon juice in a sauce pan, then add the starch/lemon mixture. Let it boil gently for one minute and set it aside to cool. Only then add the lemon zest. Incorporate it to the ricotta mixture.
Beat the egg whites to a peak with a pinch of salt, the cream of tartar, and the sugar and then carefully incorporate it into the ricotta mixture, trying not to deflate it.
Fill the molds with the mixture. A pastry bag works wonders. Fill it to the rim. Very important: run your finger around the rim and make sure is completely clean otherwise the soufflé will not rise past it.
You can place it in the refrigerator or freezer until time to cook. It is great to make ahead of time. From the fridge to a preheated oven at 360 finishes in about 15 minutes. If frozen and, the cooking time will be 20-25 minutes.