Закваска в хлебопечке. Zojirushi Virtuoso sourdough.

Zojirushi Virtuoso manual offers a recipe for one step sourdough starter. Interestingly, starting from white bread flour. At least they don't specify whole wheat bread flour or that it might be rye bread flour. They don't specify its ash content either. The manual defines 'bread flour' simply as "made from hard wheat", high in gluten and protein content.

 This bread machine has a setting that is perfect for one step starters - RISE1, which keeps the culture at 32C (91F) for 12 hrs at a time. Then stir the starter and reset RISE1 for the next 12 hrs.

It is perfect for San-Francisco sourdough type starters and Russian sourdough starters, Eric Kaiser's French liquid sourdough starter and many others, starters for German breads included. This temperature promotes growth of L. San-Francisco and other typical sourdough bacteria: L.plantarum, L.brevis, L. fermentum, and of sourdough yeast S. minor (Torula holmii).

By using that setting a good starter can be made from scratch in 12-24 hrs if using whole rye flour and Berlin method. I will show that separately

The recipe is as follows, you can read the original in Zo Virtuoso manual online p38-39.

Sourdough starter

256g bread flour (white unbleached strong flour, type 55 or type 60, i.e. with ash 0.55-0.6%)
5.6g dry active yeast (Fleishmann's is perfect, they tested this recipe with it), or 14 g fresh yeast
360g water, preferably non-chlorinated, ozonized is OK.

Pour water in the bread machine pan, add flour, yeast on top. Insert the pan into the machine and select the sourdough starter setting. Press the start button. The bread machine will mix the batter for 5 min, then keep it heated for 2 hours  at 28C (82F) and beep the completion of the sourdough cycle.

 After that, cover the bread machine pan with a plastic wrap and puncture several holes with a fork. Use the 12 hr RISE 1 setting to keep the starter at optimum temperature (32C), resetting it every 12 hours. Stir the starter 2-3 times every day, you can program the machine to do it for you.

Commentary

With unbleached white bread flour, type 55, ash 0.5-0.55% the starter will be ready in 7-10 days. Then feed it 1 tsp of sugar and 2 Tbsp of bread flour and mix lightly. In an hour you will see the bubbles on the surface that indicate that starter is active and ready to use in bread making.

Baker's yeast is added as a source of food for the microbes in flour. As it dies off in the batter with time, baker's yeast will provide nitrogen for the sourdough bacteria and yeast. In the lab environment, pure cultures of sourdough bacteria are grown on bakers yeast extracts in combination with maltose. Dead baker's yeast and maltose sugar from bread flour are a perfect food for lactic bacteria.

Let me repeat. Yeast is added as a food for Lb.San-Francisco, not as a leavening in starter.

Should the starter development take longer than 10 days, feed the starter as above, with 1 tsp of sugar and 2 Tbsp of bread flour once every 3-4 days.

  From experience I know that some white flours have very low counts of sourdough bacteria and take up to 18-20 days to develop into a fully functional starter. With dark rye flour and whole rye flour it usually takes less than 24 hours, using the same setting and the same recipe.  Although occasionally even whole rye flour might fail to produce fast results.

Illustrations
Ingredients for white bread flour starter. Canadian all-purpose flour corresponds in its characteristics to the US and Japanese bread flours.

I added a tablespoon of clear flour from the US to it (ASH 0.99%). To raise the ash % OF MY FLOUR a little bit higher and for the microbial variety in the flour. 

I use Canadian Springs water in baking. It is ozonized, not ozonated. It means that it is pure, free from from bacterias itself, but it will not kill bacteria in the starter. 

I have fresh yeast at home, but they ask for the ADY. So here we are. 

This is it! Bon voyage!

Mixed at the beginning of the 2 hr sourdough setting.

30 min later, the temperature of the  batter is 28C, the temperature of the bread machine chamber walls is 30C. Room temperature is 23C. So the machine definitely heated the batter and keeps it at elevated temperature, incubating yeast first.

1 hr later, the temperature of the batter is 28C, the batter rose to the maximum volume and is bubbling happily - gas rises to the surface and ruptures bubbles. Smells yeasty, obviously, since the concentration of yeast is very high, 5.5% fwb (flour weight basis)

By the end of the Sourdough setting cycle, full two hours later, the temperature of the batter is 27C, bubbly, 'boiling'. 

Well, this is supposed to be lightly mixed 2-3 times each day. So I turned the bread machine on, mixed the batter for 1 min on low speed. 

Covered it with plastic, made holes in it. 

And turned bread machine on RISE 1 setting. 

It keeps the starter for 12 hours at 32C. 30 min after the batter registered 32C and the walls of the Bread Machine chamber - 35C. Perfect!

I will add here updates as the starter develops. 

***

24hrs - batter fell and is no longer rising. Thin pancake consistency, tiny bubbles. No more gluten, no more sugar left in the dough. Whoever wants to eat, must eat maltose from now on. pH fell down to 5.2. Smells like overripe yeasty dough, sharp fusel-like aroma in the headspace, alcoholic, burning smell... after beating the hell out of the starter, to make it release and evaporate alcohol, it smells like wine, pleasantly fruity. I have kept it at 32C (RISE1) setting all that time and stirred it 3 times in 24 hrs. Room temperature 20C, fresh and rainy summer days. 

36 hrs. The starter completely flattened out, a thin layer of liquid started to separate on the top. Maybe 1-2 mm layer of hooch. pH is going down, which is nice. pH 4.9. The odor is less alcoholic, tastes nice, very light sourness is detectable. 

48hrs All the same

2 days +12 hrs It stinks. I think the dirty sides of the bread pan started rotting, so I washed the pan and put the starter back in to keep it fermenting at 32C in a clean environment. pH 4.5

Full 3 days (72hrs). Still smells somewhat alcoholic, but tastes really nice, acidic, mellow, not sharp (i.e. lactic acid, not acetic, not vinegary sharp). pH fell all the way down to 4.2. The problem is... below pH 4.0 bacteria won't reproduce, although sourdough yeasts will... So, I whipped the starter well, to evaporate some of the alcohol out of it and tested it with a spoon of sugar and two spoons of flour, as the recipe suggests. The starter is ready. Overnight it became foamy. 

before using it or refrigerating it for the future use, it is better to feed it first. I added to the starter in the pan 1/4 cup bread flour and 1/4 cup water. Set up Sourdough Setting, two times in a row. I.e. it was fermenting for 4 hours at 28C. It's pH was 4.2, smells really nice. Really! Very foamy.

Then I used 1 cup (250g) of that starter to make bread and placed the remainder in the refrigerator. Liquid starter can be stored up to 2 weeks refrigerated (2-6C).

Wheat bread from Zojirushi sourdough starter, baked in Zojirushi, using Zojirushi sourdough bread recipe. I used 50% white bread flour and 50 % whole wheat bread flour, so it is not pure white bread.