Salt Rising Bread Revisited

   I like salt rising bread, especially for toast, but in the past, I have had so many failures, I had given up making this bread.  It is NOT sourdough, quite the opposite.  The microbes prefer a nearly neutral medium.  The aromas from the starter, the bread, and the toast are like a strong cheese, though it contains no cheese.  Someone asked for suggestions for a good toasting bread and this was my suggestion.  It also prompted me to do a little Internet research on the topic.  I am now reasonably certain I can produce the product at will.  The critical conditions are 1/ maintain a relatively high temperature (95 to 110°F or 35 to 43°C) for the growth of the bacteria, 2/ add baking soda to control the pH, and 3/ have patience.

   I would like some of you microbiologists to give me some answers on the metabolites of the little beasties and for anyone to chime in on their salt rising bread experience.

   For reference here is my recipe and some notes on my research.

SALT-RISING BREAD, TRADITIONAL
(This is NOT a sourdough bread, but does use a naturally occurring bacterium to make the leavening)
[1/2" slice: 62 g, 148 cal, 4.3g prot, 2.3g fat, 27.2 g carb.]

STARTER (S. R. BREAD)
 
2 medium, raw, peeled, thinly sliced potatoes (~8 oz,)
1 quart (32 oz.) boiling water
1/3 cup cornmeal (1.5 oz.)
1 Tbs. (0.5 oz.) sugar
2 Tbs. (0.5 oz.) unbleached flour
 

   Put the thinly sliced potatoes in a large bow (about 2 1/2 quarts), and then pour in boiling water.  Sprinkle on the sugar, salt, and cornmeal.  Do not stir.  Cover the bowl.  At this point, the temperature of the mixture will be about 150°F.  Place the bowl in a warm (about 100 to 110°F) spot where the temperature remains fairly steady.  Let it sit undisturbed for about 20 hours.  The starter should then be foaming, with some corn meal and perhaps even a few slices of potato floating.  It should have a strong cheese-like aroma.  Remove the potato slices and discard them.

SPONGE (S. R. BREAD)
 
starter from above, without the potato slices
1 1/2 cups (12 oz.) scalded, tepid milk
1/2 tspn. baking soda
3 1/2 (14.9 oz.) cups unbleached, bread flour
1/2 tspn. (0.1 oz.) sugar
 

   Scald milk (190°F) then cool to 110°F.  Remove the potato slices from the starter and pour the rest into a large mixing bowl.  Stir in baking soda, milk, sugar, and unbleached flour, some lumps may remain.  Cover with a plastic wrap and again set in a warm (100 to 110°F) place, and let the sponge rise.  This may take as long as 4 hours, or as short as 1 1/2 hours.  When ready, the sponge have doubled in volume, will appear creamy, foamy, and still have the strong cheese odor.
If insufficient rising at this point, the dough probably will not rise sufficiently.  Cut your losses and start over.

DOUGH (S. R. BREAD)
 
all of the above sponge
~9 1/2 cups (40.0 oz.) unbleached bread flour
1 tspn. (0.2 oz.) sugar
1 1/2 Tbs. (1.0 oz.) salt
1/4 cup (2.0 oz.) melted and cooled butter
butter or solid shortening for greasing pans
melted butter for brushing dough
water in a sprayer
 
77% hydration

   Put 4 cups of flour, 1 tspn. sugar, and 1 1/2 Tbs. salt into bowl containing the sponge, and blend.  Stir in the melted butter. Then add enough flour (4 - 5 cups, or more) to make a soft, manageable dough that you can knead.
   Turn dough onto a floured surface and knead for a minute or two, adding flour as necessary.  Let it rest for ten minutes.  Resume the kneading until the dough is smooth and elastic, adding flour as necessary.  Divide into three loaves (about 2 lb. 1 oz. each), and shape each piece to fit the loaf pans.  Place each into a greased loaf pan, brush with melted butter, and cover with plastic wrap.  Set loaf pans in a warm place (100 to 110°F) to rise.  This final rise takes about 2 hours, and the loaves should double the original volume.  Let the loaves rise until just above the top of the pan, and do not slash the loaves.

BAKING (S. R. BREAD)
   Preheat oven to 450°F (with a pan of boiling water on the bottom shelf) and the middle shelf reserved for the bread pans.  When the dough has risen, spray the dough with water, and place immediately into the oven.  After 15 minutes reduce the oven temperature to 350°F.  Bake until the interior temperature of the loaves is 195° to 200°F.  There will be little or no oven spring.  They should sound hollow when thumped with a finger on the bottom, about 40 minutes.  It is better to overbake than to risk underbaking.  Turn out on to a cooling rack, brush with butter, and cover with a damp cloth until cooled.  Bread may then be packaged and frozen.

NOTES (S. R. BREAD)
   This is NOT a sourdough bread.  On the contrary, the organism responsible for the leavening prefers a near neutral pH, slightly on the basic (alkaline) side.  The baking soda (sodium bicarbonate) is added is to obtain that pH not to leaven the dough.  Were the baking soda not added, the acid produced by the bacteria would greatly slow the growth of the bacteria, if not kill them.  Another difference is that this organism prefers a much higher temperature, 100 to 110°F (38 to 43°C).  This temperature would kill the sourdough yeast and lactobacteria.  The bacterium responsible for leavening salt rising (SR) bread is anaerobic, i.e., it thrives in the absence of air, whereas the yeast and lactobacteria of sourdough can metabolize their nutrients either aerobically or anaerobically.
   Clostridium perfringens is reported to be the bacterium responsible for the leavening of salt rising bread (1, 2) ,    Apparently, the spores of this bacterium are wide spread and present in all grains and other vegetable mater.  Nielsen (2) has reported making salt rising leavening from many different starting materials viz., various grains, cheese, and even the bark of white oak, and the bark of black locust.  Apparently, it is the high temperature of the milk or water that activates these spores and then the continued temperature of about 105°F that promotes the metabolism of the bacteria.  The gas produced is said to be mostly hydrogen. (3)
   A proofing oven is ideal for the various rising steps.  One can be made of a large cardboard box with a light bulb for heat.  (Do not let the bulb touch the box.)  Our oven with the oven light on gives a temperature of about 105°F, perfect.  A gas oven with only the pilot light on may work.  Be sure to measure the temperature of the proofing oven (or area) — too high a temperature kills the organisms and too low (below 95°F) will not permit fast enough growth.  A temperature of 105 to 110°F seems to be about ideal for proofing.  This organism likes a higher temperature than does yeast.
   As the dough matures it looses its elasticity.  The risen dough in the baking pan will jiggle like a bowl of jelly as it is placed in the oven.  This is probably due to the bacteria having metabolized the gluten and thus destroying the network that retains the gases and gives structure to other breads.  The metabolites of this nitrogenous compound may well be the source of the cheese-like aroma.
   Do not use any product that has a live culture in it such as sweet acidophilus milk, yogurt, or buttermilk.  Or, at least scald (190°F) such a product to kill any active organisms.  The organisms may be antagonistic to the leavening organism.  Do not add any acid product at any stage.
   Be careful of preservatives that may be in the various ingredients.  They may kill the leavening organism.  Salt is a preservative; too much will slow or stop the leavening process.  Since the bacterium is anaerobic, avoid beating air into the starter, the sponge, and the dough.
   If at any time in the process the product does not appear to be working, i.e., generating the gases needed for proper rising and having a cheese-like aroma, discard it, and start over.  The starter must generate a good deal of foam, the sponge must also foam, and the dough must at least double in bulk.  The most likely cause for failure is either too high or too low a temperature during proofing.
Do not overproof the loaf – let it rise until it is just above the top of the loaf pan.  Do not slash the top of the loaf.
   Jenny Bardwell & Susan Brown, eHow Presenters, made a good video on methods for making sourdough bread.  See: http://www.ehow.com/video_2340947_salt-rising-bread-recipe.html

Ford

foot notes:

(1)  H. A. Kohman,1953 Baking Industry: http://home.comcast.net/~petsonk/SRB03.10a_files/Page416.htm

(2)  Reinald S. Nielsen, http://www.nyx.net/~dgreenw/whatissaltrisingbread.html

(3)  http://home.comcast.net/~petsonk/SRB03.10a_files/Page416.htm