International School of Baking:  Marda Stoliar and Associates, consulting, Culinary arts school – professional training for baking European breads and pastries and complete bakery start-up    

Sourdough Tips

Dough Tips | Sourdough Tips | Metric Conversions

Sourdough Information Sheet  (for Basque & French natural leaven starters)



General Tips

  1. Never allow any form of metal such as a spoon or lid to come into direct contact with the stored, un-used sourdough starter as it will cause a chemical reaction that will contaminate and blacken the implement and eventually in time will kill (loose all activity) the starter and a blackish blue or pink liquid will surface, and the starter at this point, can’t be revived. 

  2. Do not use any clay crock type container because the possibility exists that there are trace metals or minerals  present in the glaze or in the clay itself which in time can  leach into the starter, that could impact adversely the starters activity or cause future health problems with the people consuming products made with the starter on a regular basis.  Glass containers are used my many people but I do not advise it when using my French starter as it is very activity and would probably break the jar.

  3. The container should have a lid with an “easy fit” that will allow some “off-gassing”, and be kept on but loose, at all times between feedings.  For this reason the regular refrigerator containers are not suitable as their lids fit too snugly and will blow off as the pressure builds up when gasses increase.

  4. Always separate starter into two containers and use one as a “back-up” and the other as the “working starter”.  The back up starter is one that is kept in a small quantity plastic container (approximately 2 cup, 500 ml capacity), slightly less than half filled. This portion of starter remains in the refrigerator or freezer and is nourished once every 2 months. This starter is a “fall-back”, in case the working starter becomes contaminated. This portion of the starter will keep a sweeter smell than the working portion, this is normal. The third option is to keep an air-dried starter dry and in a dark place until needed.

  5. To activate “air dried starter”, Place the air-dried starter in a 2 to 4 quart container that has a loose fitting lid and leave the lid slightly open, add equal portions flour and water by weight, not overwhelming the starter with too large a quantity of flour and water, added to the dry starter.  Place starter container in a 80 to 85 degree F area, feeding every 6 hours even if the first few feedings no bubbles are present which would indicate activity.  Once bubbles are present, feed as the starter demands. Allow a day or two to activate the  starter, when the bubbles appear and are covering the top and sides and are viable up the sides of the jar, give another 24 hours or more before using as the flavor must be developed.

  6. The working starter is kept in a larger clear plastic container that will allow for multiple feedings (approximately 3 to 4 quart capacity). The amount of starter kept in this container is relatively unimportant but the minimum is 1.00 lb. (454 grams).  The reason for the large size container is for the ease of building up to the amount needed for baking without changing containers.

  7. A clear see-through container allows the viewing of the starters bubble formation. The bubble formation tells the condition and the vigor and when the starter needs to be fed.

  8. Never use glass container, because an active starter in a glass container with a tight fitting lid could explode from  internal pressure

  9. It is critically important to keep a clean starter container at all times.  A build-up of dried starter around the top edge is easily contaminated and can adversely effect the entire starter.  Once every couple of months clean another container and lid thoroughly with boiling water, transfer the starter.  Wash the starter container with soap and water, (not detergent) removing  any crusted starter that may exist.  Return starter to the container, feed and use or refrigerate as needed.

Feeding of Starter

To feed starter: 

  • Some people feel that any off-colored  liquid that has surfaced on the starter should be poured off. I feel that  If the liquid is not overly  discolored, it is not necessary to pour it off. 

  • Use tap water as long as it is non-“softened water” or if in doubt of your waters contents, use filtered spring water. 

  • Use a good unbleached, organic and if possible un-bromated medium bread flour in approximately equal amounts that equal at least 50% of the starter itself.  Mix well but do not over mix enough to develop any gluten structure in the flour.

  • Stir the flour and water in with a plastic or wooden implement that has been cleaned with boiling water or use disposable chopsticks as a safe alternative.

Feeding the starter for use:

  • Normally the starter should be brought out of refrigerator at least 48 hours before it is needed for baking.   Start feeding starter approximately equal portions of the water and flour by weight. Stir down starter after feeding and place in a warmer area in the room at least 80 degrees F but preferably 85 degrees F. and feed starter again when the bubbles on the sides of the container are uniform in size from top to bottom, this will be approximately every 5 to 10 hours depending on room temperature, activity level of the starter  and weather conditions.

  • Continue this procedure until desired quantity is achieved.  The important feeding is the last one approximately 5 to 6 hours before use.  This feeding must consist of more flour than water so that the starter becomes the consistency of very thick apple sauce.  The starter should be as thick as you can stir with a chopstick.  The last feeding, allow the bubbles to form in a uniform pattern through out the starter  before use.

  • In the case of a “sponge and dough” formula, a starter can be used straight from the refrigerator up to 50% of the sponge weight itself, and placed in with a sponge and let sit for the 10 to 12 hours before being placed in the dough portion of the formula with possibly only the salt to be looked at ( to bring the salt into the minimum 1% and Maximum 2% range) and maybe the % should be raised, other adjustments such as the deletion of the yeast, need not be made.  This method enhances the flavor of the sponge and add to the shelf life of the finished loaf.

  • Starter is sometimes used as a flavor only such as in crackers or pizza crust.  When used as a flavor it is used directly from the refrigerator or from a room temperature multiple fed starter but placed in the formula and baked within a 2 to 4 hour period. In this application it is being used as a sponge.

  • Always feed un used starter once more before returning it to the refrigerator and allow 15 to 30 minutes at room temperature after feeding before returning starter container to the refrigerator, this acts as a sugar fuel to the starter. The starter does not really stop its fermentation activity when refrigerated but just becomes slower.  In fact one should check the starter container every few days while in the refrigerator to make sure the lid remains on the starter, burping lid if necessary.

  • Keep refrigerated at 35 to 39°F (1.6 to 3.8°C) when not in use.

How to hold starter un-used for prolonged periods of time

  • When starter is not in constant use:  Every 1 to 2 months, remove from refrigerator, let come to room temperature, pour off liquid if necessary and feed as described above and let sit at room temperature for 1 to two hours, stir down and refrigerate for later use. Starter can be air-dried on clean parchment in the following manor: Spread a thin layer of thinned starter out on parchment paper, let it naturally air dry, it will flake and release itself from the paper as it dries.  When totally dried, place the chips of starter  in a dark dry covered container.  To activate starter, place chips of starter in starter container, add equal weights of water and flour to make a good semi-stiff consistency as you would for a normal feeding.  Place semi-covered container in a  warm location.  It may take 2 to 3 days for full activity to return. 

  • Never return any “old dough” or  dough of any kind to the starter container.

  • The introduction of old dough containing salt or commercial yeast would compromise the taste and quality of your natural levan.

  • The regular starter can be altered to become a semi-rye starter by substituting about 1/10th of the white flour quantity with  rye meal coarse or coarse rye flour to every 4th feeding.  This will create a more active starter and can be used in country type white bread loaves or used in rye sourdough breads of any kind in place of, or in addition to, a regular starter or sponge. The introduction of rye to the starter changes the starters ph factor and becomes “sweeter”.

  • Starter that is fed looser, meaning more water to flour ratio, will yield a more acid finished loaf and may be more active, giving off larger and more random crumb cell structure than the starter that is fed thicker. The thicker starter will usually give a sweeter and more even crumb finished product, due to the available sugars in the flour itself and the less available hydration.

Objectives of the use of Sourdough

Fermentation properties of sourdough have various favorable effects on bread dough:

  1. They stabilize the baking ability of rye.

  2. They give the bread an aromatic flavor.

  3. They tenderize the bread crumb.

  4. They make the bread crumb firm yet elastic.

  5. They improve the shelf life properties and the durable life of the bread.

Method & Characteristics Using  Sourdough Starter in Rye Bread

  • Rye bread designed with 0% and up to 1.6% commercial yeast and 1.8% salt,

  • 35 to 40% sourdough starter

  • 80 to 82 degrees F, dough temperature coming out of the bowl,

  • 10 to 30 minutes resting time( table time or first proof),

  • 89 degrees F proof box temperature for final proof.

  • 50 minutes final proof time,

  • baked at 428 degrees F in conventional oven with some form of humidification.

  • These guide lines will yield a better more moist loaf of rye bread with good crumb structure, losing approximately 12% moisture content in the baking process with good molding and shaping qualities exhibiting aromatic round yet sharp rye flavor.

  • Desired ratio of lactic acid to acetic acid are:

    • 75 to 80% lactic acid

    • 20 to 25% acetic acid.

  • The acid value measures the quantity of acids present in sourdough; the pH value measures the strength of the acids in the sourdough.

Sourdough Properties & Handling

Fermentation of sourdough is caused by micro-organisms in flour and air found everywhere in the world.

The desirable organisms in sourdough are:

Schizomycetes (acidifiers)

1. Lactic acid, which forms in soft doughs at temperatures of 95 to 100 degrees F.

2. Acetic acid, forms in a stiff dough at 100 degrees F.

3. Budding fungi which creates alcohol and Carbon dioxide, which finds its optimal environment in softer doughs which contain high oxygen levels where the cells can easily multiply.

When slower doughs are required:

  • Use 18% sourdough starter to the flour 100% in the formula.

  • Slightly higher salt level 1.8 to 2%

  • Mix quickly.

  • Mix a firmer dough

  • Hold dough in cooler temperatures for both fermentations. 76 to 80 degrees F.

  • Yields a sweeter bread with a more even crumb structure.

  • Touch of rye in the starter will yield a sweeter faster natural yeast activity.

When a more active dough is needed:

  • Use 30% or more starter to the flour 100% in the formula.

  • Mix slowly and stop slightly under-developed.

  • Mix a softer dough with a higher level of hydration which will allow more slippage and a more random crumb structure.

  • Using 85 to 89 degrees F for both fermentations. 3 hour fermentation time.

  • Yields a more full bodied acid loaf, thinner crust with a greater pull.

Join Our Mailing List

© 2004 International School of Baking | Bend, Oregon USA  |  Web Design by Schloer and Associates
Home | Consulting | About Us | Gallery & Resources | Formulas | Testamonials | Fees & Dates | Bakeries on a Budget | Courses | Location | FAQ's | Contact Us