breadbythecreek's blog

If you've been following this blog, when we last left this subject, I was trying to determine which of my many jars of YW I should keep. I have decided that having multiple jars of different fruits is pointless, since it is near impossible to tell which fruit was used by either taste or smell.  Some color will be added from darker fruits, but that's about it.  So, the first trial to see which fruit water was the most effective (the most rise in the least amount of time) revealed that my water made from cherries (initially with dried, then switched to fresh) jump started with strawberry water, was the winner. 

The second heat was to test the cherry water against apricot and raisin.  I ended up having two raisins as my first raisin water was discouragingly slow to activate.  I purchased new raisins from a different source and started a second jar.  One variable that I hadn't accounted for was the relative amount of sugar in each of the solutions that I tested.  To better calibrate this for the second heat, I obtained a brix meter (for wine making) and was able to test each solution straight from the jar and add an appropriate amount of fresh water to bring the solutions to the same level of sweetness across the board.

It was interesting to compare the brix readings from the various jars.  At just 3.4, the winner of the first round, cherry, had the lowest brix.  The older raisin had a brix of 3.6, followed by the new raisin at 3.9, and finally, the apricot had the highest at 5.0.  Since I was after a final test amount liquid of 10g, I calculated the amount of fresh water to be added to each tester to bring all of the testers' brix to 3.4.

Initially, I tried to use a 100% hydration for the test runs (10g solution added 10g bread flour).  However, the paste was too thick to go down my new test tubes, so I had to increase the hydration to 143% (10g solution to 7g bread flour). This created a liquid enough paste to go down the tube and still have enough viscosity to rise back up.  

The following photos show the progress 1, 2, 3, 4, and 5 hours into the race. Testers are from left to right:

raisin2 (new raisin), apricot, raisin1 (old raisin), cherry

 As you can see, from the start, apricot and old raisin were much more active than the other two, just an hour into the race they were pretty much neck and neck.  Cherry and new raisin barely moved.  

After two hours, cherry had picked up some speed, but raisin2 was still thinking. Apricot was in the lead after two hours, followed close behind by raisin1.
    Three hours in, apricot still leads, raisin1 a close second, cherry is picking up, and raisin2 still stuck at the gates.

 Four hours in, apricot and raisin1 neck and neck, Cherry is stalled, but raisin2 is coming alive!

At the finish line, 5 hours after the start, we have a winner. Raisin1 peaked at the top of the tube, Apricot never made it that far.  Had I let Cherry and Raisin2 go, they may have gone farther, but I called it: Raisin1 will live to rise another day!

The question I had is what would happen if you fed a Blueberry Yeast Water/Bread Flour levain additional Blueberry Yeast water, using seeds from previous levain builds.  Namely, what is the effect of increasing population of blueberry yeast over a series of builds while holding the overall volume constant.  Would there be an improvement or degradation in rise times or volumes?  Would there emerge a limit as to how quickly a doubling or peaking would occur?  Would it explode into a new black hole? These were the questions that I just had to answer for myself.

Methodology

I started with 10g blueberry yeast water (BYW) and 10g Bread Flour (BF). This was left to rise to its maximum height and plateau, whereupon it was chilled for the night.  The next morning 7 grams of this levain was fed 7g BYW and BF, and again left to rise to it’s maximum height and plateau, then chilled or refreshed.  Using time-lapse photography (thank you RonRay), I was able to track the level of growth for each build on 15- minute intervals. I intended to continue this refreshment pattern and observe the action until the growth/plateau cycle was found to closely resemble the previous builds or something else happened to draw my attention away. 

 Findings

 The following graph shows the results. 

Just looking at the doubling times, clearly the more iterations of builds shortens the time required for the levain to double.  R1 took almost 7 hours to double, whereas R2 took 5 hours, and R3 took 2.5.  Most of the trials R3-R7 in this 2-2.5 hour range to double. By far the fastest doubler was R8, at just 1.5 hours.

There is also interesting phenomena with respect to the period of growth before plateauing.  R1 took about three hours take off, presumably adjusting to the new food/environment, and didn't fall off until almost 8 hours after the first feed (5 hours of active growth).  R2 took an hour get going, but fell off an hour quicker than R1, (six hours of active growth.  R3 didn't lag at all. It grew from the time that it was fed and continued steadily for almost 6 hours.  R4-R6 all took off from the get-go, and enjoyed a solid 4-4.5 hour growth stage before plateauing.  The standouts were R7 and R8, which both not only took off from the start, but also, grew for an astonishing 6 hours before exhaustion.  So something about more yeast in the culture allowed for a longer growth stage, despite a finite and constant supply of food.

The peak volumes also varied with the yeast concentrations.  The lowest amount of yeast, R1 was barely able to double (2.3X) before giving up.  R2 was slightly better at 2.5X. R3 and R4 made it just to 3X. R5 and R6 got to 3.5X, but again, look at R7 and R8. They got to an impressive 4X! It took them a long time, but they never lagged, they just kept going, and going and going.

From a temperature perspective, there is apparently an outside, uncontrolled effect.  As we can see, the cycles R3-R8 closely track each other.  The cycles of R7 is very similar to R5, both of which were started first in the day, from seed chilled overnight in the refrigerator.  R8 proves to track closely with R6, indicating a typical afternoon pattern. So there may be a distinct positive effect from room temperature (it gets hot in the afternoon here now (86*F+).

In conclusion, I believe a YW builds should be fed subsequent builds with more active YW until a doubling can be achieved within about 2 hours and the capacity of growth is around 3x or more, usually by the third build.  Given the time and desire for even stronger levains, subsequent builds using active yeast waters will not have a detrimental effect on your doughs, although some care should be taken to avoid overproofing.

An aside... In a separate experiment, I discovered that this Blueberry Yeast Water is the least effective of my collection, bested by far by the Cherry Yeast Water.  I intend to repeat this analysis using the Cherry Yeast Water instead.

Again Stay Tuned...

-Pamela

I’ve been experimenting with various types of yeast water for several weeks now.  I now have five separate jars percolating on the counter or in the refrigerator.  Since I’ve discovered that very little if any fruit flavor is discernable in baked breads made from these waters, it makes sense to me to keep only one.  It also makes sense to me to keep the one that is the most effective.  I have heard that raisin yeast water is the strongest and most active.  When I first started experimenting with these waters, I made a raisin/apricot yeast water, but the color and murkiness was not appealing, so I threw it away shortly after it was created.  Today I am making a new jar with just raisins and another with just apricots.  These will be tested against the winner of this trial.

To see which of my active yeast waters are the more effective, I created test waters containing 30g each of peach, blueberry, strawberry and cherry.

 To these amounts I added 90g fresh water and one sugar cube. These jars were left out overnight to activate the yeasts.  This morning I took 3 grams from each of the jars and 3 grams of AP flour. These were mixed together and placed in identical test-tube like glasses (tall and very narrow).

9:30am, roughly 3 hours since start time

 Now it is four hours into the test.  Gauging from my ongoing work on the blueberry yeast water, this first build will take approximately 7.5 hours to plateau.  Halfway through, it seems that the growth pattern of the testers matches too closely to the order in which the tests were prepared, lagging perhaps by no more than 5 minutes from the first (cherry) to the last (peach).  Also, both the strawberry and the peach were slightly more hydrated than either blueberry or cherry.

At 12:31pm, roughly 6 hours later, it appears that the cherry levain is far stronger than either the blueberry or the peach. The strawberry levain is only slightly behind the cherry in growth.

At 2:09pm, roughly 7.5 hours later, it is still cherry in the lead.  At this point I noticed that the glasses are not identical – some are deeper than others.  This accounted for, the cherry is still slightly more effective than the strawberry.  Also, approximately at this same time, cherry had reached its maximum height, approximately double the start level.   Strawberry went on to double at approximately 8 hours, as did peach.  Blueberry, interestingly enough, did not achieve more than a 50% growth over the entire period.

So there you have it. In terms of overall effectiveness for a first level build, cherry is the strongest of the test set.  The rest are not as effective for raising culture in a given period of time.

Next trial, Cherry against raisin and apricot.  Stay tuned.

 The last set of experiments was to determine whether the use of fruit based yeast in the absence of flour in the starter would result in more fruit flavor in the final loaf. Much time and effort went into weaning my standard sourdough starter from a diet of wheat flour and water to a diet of pure fruit puree.  This starter was used to create a boule with the starter, AP flour and peach puree. The result was less than spectacularly peachy. 

 This time the fruit was blueberry.  I initiated my starter from my blueberry yeast water and bread flour, and through  successive refreshments (5X), I created sufficient starter for the following loaf.  I don’t know, but I suspect the loaf was once again, overproofed as I ended up with yet another “muffallata” loaf. The color of the crumb is most striking, almost like a pumpernickel.  The taste is faintly blueberry, sweetish. With cream cheese it tastes very much like a bagel.

Formula: 

70g starter (10 starter/30 flour/30 BYW @100%)

158g blueberry puree (132L,26S)

175g AP flour

4g salt

234:166 = 70% hydration dough

total loaf =407g

To make this loaf, I took 9g of the starter (4th refreshment) and fed it 30g each bread flour and blueberry yeast water.  This I left at room temperature for about 3 hours until it has more than doubled. Then I combined it thoroughly with the blueberry puree, which interesting enough was more like a jelly than I expected, there must be lots of pectin in blueberries.  I stirred in the flour and the salt, gave it a S&F and let it rest for ½ hour. This was repeated for three hours, then not thinking, I put it in the cooler (46*F) for about 3 hours.

Then, remembering that I needed to shape it, I took it out of the cooler, preshaped it and left it out for 30 minutes. Then I shaped it into a boule and placed it into the floured banneton.  This was replaced into the cooler for the remainder of the night. 

The next morning I took it out of the cooler and let it warm up until the oven and combo-cooker was up to temperature (460*F). The loaf was baked for 20 minutes with the cover on, 10 minutes with the cover off, and an additional 10 minute with the oven door ajar.

We recently got very lucky and were able to buy a flat of the best peaches we have ever had. These peaches, just picked, ripened on the tree, are pure peachy goodness. At the same time, I’ve been experimenting with water/fruit fed yeast in bread baking. As a result of this experimentation I’ve discovered that it is next to impossible to get any fruit flavor from Yeast Water to be present in any baked bread. The water from the fruited yeast is just too subtle. Yes, the fruited yeast water has a nice effect on the crust (crunchy), crumb (moist and tender) and on the color (esp. with red/purple fruits), and taste (absolutely not sour). However, one would be hard pressed indeed to tell which fruit was used to prepare the yeast water. This is discouraging as why go to the trouble of using beautiful fresh, fragrant, and hard-to-come by fruits when any old bag of raisins will do exactly the same thing?

The first step was to convince my standard grain fed sourdough starter to like, and want to eat the sugars contained in peach puree. Taking my cues from Ron Ray, as documented in his Banana Saga, I slowly weaned my standard wheat based sourdough starter to accept a diet of first AP flour and peach puree until I reached the point where there was no more water in the starter seed. From there, I began the process of weaning my starter to accept a diet of pure puree (no AP flour), again to the point where there was no more flour in the starter seed.

 Now this starter ready to be developed in the final dough. I wanted to create a dough that relied solely on peach puree for the water content (Google assures me that peaches are 80% water). Thus, peach puree is comprised of 80% liquid and 20% solids. As is the recommendation, I set about creating a dough that was approximately 1/3 preferment (in the form of fermented peach puree), and was at approximately 75% hydration (e.g., liquids as a proportion of solids) and holding the overall loaf size to approximately 400g, yielded the following formula:

Ingredients

• 60g Starter 
• 185g Bread Flour
 (plus 11g extra)
• 150g Peach Puree
• 
4g salt

Preparation

I combined the 60g fizzy starter with the 150g peach puree. Then I slowly incorporated the 185g bread flour to form a rough, sticky dough. I covered the bowl and let it rest for 20 minutes to hydrate the flour. Then I mixed in the salt.  This was given the first stretch & fold (S&F) in the bowl and left to rest for 30 minutes. At this point, I was forced to alter my plans and work in an additional 11g of bread flour. The dough was just too sticky and not holding together.  This S&F/rest process was repeated a total of four times over the next 1 1/2 hours. After the final S&F, I left it to rest an additional 1/2 hour before I turned it out onto a lightly floured counter (approximately 8g flour) and preshaped and shaped the boule. This was placed in a floured banneton and into the 46*F cooler overnight (approximately 11 hours).

The following morning, as is my habit, I took the dough out of the cooler and let it come to room temperature. About half an hour into this warming up period, I began to preheat the oven and the combo-cooker to 450*F. This takes about 1/2 hour. When the oven was fully preheated, I removed the cooker from the oven, overturned the dough onto the parchment, slashed (not very well, hmm.), and slid the loaf to the bottom of the hot cooker. Placing the lid, back into the oven the whole works went for 20 minutes. After 20 minutes, the lid was removed—The moment of truth, pancake, hockey puck, boule? What would it be, well, as it turned out, peaches are not the best for massive oven spring. I wouldn’t call it a pancake, somewhere bigger than a hockey puck, but not much. After removing the lid and turning down the oven to 425*F the loaf was baked for another three minutes, then I removed the bottom of the cooker and the parchment, and placed the loaf directly on the stone. This is where it remained for another 7 minutes. Then, I propped open the oven door for an additional 10 minutes (total 40 minutes in the oven). Then I removed the loaf. Well, it does smell of peaches.

 Way too much flour in the banneton - I was worried about sticking.  The oven spring is not great, sort of like it was overproofed. It sounds hollow when I thump it and the crust is quite thick and hard. So. Now comes the real test. After all of this work and experimentation, did I create a peachy tasting peach bread? Here is the shot of the crumb:

 As you can see, the crumb is definitely a peachy color, moist and tender. There are bits of peach visible in the crumb. Does it taste of peaches- yes, faintly.  It tastes almost like a not-so-sweet cake, not a bit sour, which is not surprising.

 
If someone were to not tell me peaches were 51% of the mix, would I ever be able to figure that out?  No. Alas, I think the pursuit of pronounced fruity flavor in the crumb of a yeasted bread needs something more than peach puree.

Happy Baking!

Over the last couple of weeks I've been experimenting with the properties of fruit based yeast waters. Starting with a strawberry water, I've so far transformed Txfarmer's 36+ hr baguette  from a standard sourdough to one fed strawberry yeast water.  The result was as to be expected, crunchy crust, moist crumb, not a hint of sour, and interestingly, a surprisingly dark color despite the exclusive use of AP flour in the dough.

Strawberry Yeast Water Baguette, and one with Peach Yeast Water - Same recipe, same flour.
  

I have also created a number of boules using Ron Ray's Darling Clementine recipe.  I've used that same boule recipe to create a strawberry, cherry and blueberry boule.  From these loaves I have come to some conclusions.

Once out of the oven, these boules are virtually indistinguishable in terms of color, crust, and crumb. The only distinguishing feature was the strawberry loaf aroma while it was still baking. So, my conclusions are that it matters little exactly what kind of fruit one uses to cultivate yeast (except of course for those containing actinidain or actinidin), only that the yeast exist. Fruit based yeast from these types of waters will alter the color and consistency of the bread but will not impart any fruit essence upon baking.  The reddish/purplish fruits that I tested will significantly alter the color of the crust and crumb, and the relative amount of sugar present in the water will also affect the taste (the blueberry water, made from a quantity of dried blueberries was quite sweet to begin with).

 Strawberry, Cherry, Blueberry Boules: Beauty Shots, Profiles, and Crumbs

 I think after this experiment, I'll retire all but the strawberry water, as it is the most pleasing in terms of aroma, at least when it comes out of the oven.  So, in conclusion, choose your favorite fruited yeast water and keep only one type. Also, don't forget to feed your sourdough starter too because what is life without a little tang?

Happy Baking!

-Pamela