About hydration of starter and dough
You do not have to understand hydration to create beautiful prosphora. But it helps to know how various factors affect our gift offering, its appearance, and its taste. The hydration level of a starter and of a dough has great impact on every aspect of the process and determines the results we get. Understanding hydration helps you to perfect your prosphoro.
WHAT IS "HYDRATION LEVEL"?
The hydration level is a measurement of how much water is contained in a starter or dough. It is reported as a percentage. For example, if we use the same amount of water by weight as flour, our mixture has “a 100% hydration level”. (e.g. 50 grams of water in 50 grams of flour).
The hydration level is the biggest factor determining the texture of your prosphoro… its crumb, the size of the air cells, how the dough behaves and much more. The image above shows sourdough bread made with a "high hydration" (68%), next to a prosphoro made at 51% hydration.
In the preparation of prosphoro we aim for a low hydration dough, compared to breads for other uses.
LOW HYDRATION DOUGH
· More difficult to incorporate all ingredients evenly
· More firm
· Less sticky
· Takes longer for the gluten matrix to develop so it requires more kneading
· Retains its shape and the impression of the stamp better
· Ferments more slowly
PROSPHORO BREAD QUALITIES (compared to other breads)
· The texture is firmer with a less open crumb (i.e. tighter smaller air cells)
· Thinner crust
· Prone to a more sour taste unless we are careful to keep this controlled
· Prone to a higher rise (so we need to be more careful with baking at the apex of the rise. If we bake before the apex, we will get an abrupt oven spring with rips. If we bake past the apex, the dough may flop and become dense).
SMALL CHANGES TO HYDRATION
Even very small changes to the hydration levels significantly affect the qualities of your dough. I have experimented with just 3-5% higher hydration level and found the dough sticks to my fingers, makes the shaping difficult and I had to spend hours trying to clean the dough out of the crevices of my seal! The prosphora I made with 54% hydration matured a little faster but were covered with air bubbles on the surface and had larger air cells in the crumb.
CALCULATE THE HYDRATION LEVEL
Take the weight of the flour.
Determine the weight of the water (NB in our “recipe” we use half the weight of the flour as the amount of water)
Take the weight of your starter. (Since your starter is at 100% hydration, half that weight is flour and half is water).
Calculate the weight of the TOTAL FLOUR ( weight of flour plus half the starter weight which accounts for the flour in the starter)
Calculate the weight of the TOTAL WATER (weight of the water plus the water from the starter)
TOTAL WATER WEIGHT divided by TOTAL FLOUR WEIGHT x 100 = percentage HYDRATION.
THE IDEAL HYDRATION LEVEL FOR PROSPHORO IS BETWEEN 51 – 52%.
· 1000 gr flour
· 500 mls (grams) water
· 50 grams of 100% hydration starter (which is 25gr flour with 25ml water)
· Total flour is 1025gr
· Total water is 525mls (grams)
· Therefore 525/1025 x 100 = 51.2% hydration
An example with more starter
· 1000 gr flour
· 500 mls water
· 100 grams starter (10 % of weight of flour)
· 550/1050 x 100 = 52.4% !
This is already getting a little too wet so I would reduce the amount of water by 15mls. This will give a hydration of 50.9%. (I.e. I would add only 485mls of water to the 1000 gr flour and 100 gr starter.)
NB. Some small variation may be required since different flours need slightly different levels of hydration. Find a good, high protein organic white bakers flour and stick with it for everything from your starter to the prosphoro. You will get to know it and intuitively make any changes it requires for best results. Only experience confers this.
HOW DO HYDRATION LEVELS AFFECT THE STARTER?
At the recommended 100% hydration level for our starter, we find it is soft enough to mix into the other ingredients easily. Once vigorous, it needs feeding only weekly when kept in the refrigerator. Higher hydration than 100% means the microbes feed more readily and quickly and spend their supply faster. Lower hydration levels favour the microbes which produce more acetic acid – making it and the dough more sour.
LESS SOUR STARTER AND BREAD
Firstly its important to understand that the microbes in a natural starter are made up of two broad groups. There are lactobacilli which are similar to the microbes which change milk into yogurt. These produce a more mild, milky tasting and richer flavour. The other group are yeasts of different strains. These produce more acetic acid and thereby impart a more vinegary sour taste.
Lactobacilli thrive best at temperatures between 18- 26 degrees Celsius, and in environments with more water. The other microbes prefer higher or lower temperatures than these and do very well fine in environments with less water.
FOR A LESS SOUR PROSPHORO
Avoid long fermentation times.
Choose temperatures around 20-26 C; too high and the acidic yeasts predominate and too low causes a slowing of the rise and again, more sourness)
Use a fresh starter. Consider feeding your starter before you use it.
Once you have fed it, try to use the starter when it has risen about halfway to doubling it’s height. If you use it too early, it hasn’t gained momentum – in effect, you are using the small amount of starter whose microbes haven’t begun multiplying and making them do all the work… so the rise will be slower and the results more sour.
If you use the starter after it has doubled its height, it will have spent all its food and created more acidic waste and hence it will be more sour.
Paradoxically, using more starter produces a milder tasting prosphoro. (Go for 10% of the weight of flour as the weight of starter to use). If you use a small amount, the maturation takes much longer and as mentioned, this favours sourness.