Don's Starter Part 2.

I stated in a previous post that I would be doing further experiments with Don's starter in an endeavour to find out more about it. The following is what I have done.

NOTES> At all times during the following, I have done all possible to ensure no cross-contamination of starters or doughs. To minimise as much as possible any time differences, all ingredients were pre-weighed. The water component was taken from a common large container to ensure equal temperature. When mixing time was required it was done so as to minimise any bias, that is, when mixing for the starter test the expected slowest starter was mixed first so as not to artificially accentuate the speed of the faster starters. When mixing for the baking test Don's starter was mixed first, time difference no more than 3 minutes.
For the starter test a more visually spectacular result could have been obtained by using a greater volume of starter at a higher hydration, however I chose 100% hydration as this is what the starter in Don's recipe calls for.
During the course of both tests, room temperature was 22C (aircon) and unless components were being mixed or stretch/folded, they were kept in a thermostatically controlled proofing box at 25C.

TEST 1. AIM. To observe the relative speeds of 4 different starters. The elapsed time is less important than the relative speed, as the elapsed time can be varied by the hydration level.
METHOD. Four starters were selected, Aus (mine), Alaska (Teresa) Don (Donyeokl) and Yeast.
The Alaska starter is a known fast starter see http://www.sourdough.com.au/phpBB/viewt ... highlight=
The yeast starter was created using 3g of Defiance instant yeast, 100g water, 100g bakers flour.
All starters were refreshed three times before the test. For the test 60g of each starter was mixed with 150g water and 150g of 11.5% bakers flour. 200g of this mix was then poured into the test containers. You can see the results below:-

[img]http://www.sourdough.com.au/gallery/d/4162-1/1+Hour.jpg[/img]
[img]http://www.sourdough.com.au/gallery/d/4164-1/2+Hour.jpg[/img]
[img]http://www.sourdough.com.au/gallery/d/4166-1/3+Hour.jpg[/img]
[img]http://www.sourdough.com.au/gallery/d/4168-1/4+Hour.jpg[/img]
[img]http://www.sourdough.com.au/gallery/d/4170-1/5+Hour.jpg[/img]
[img]http://www.sourdough.com.au/gallery/d/4172-1/6+Hour.jpg[/img]

The results are self evident. The yeast is obviously the fastest, doubling in 2 hours and peaking at 4 hours. Don was the next fastest doubling at 4 hours and peaking at six. Alaska doubled at 4 1/2 hours and peaked at 7.
CONCLUSIONS. While Don was faster than a known fast starter, it took twice as long as Yeast to double. From this one could reasonably assume that it is not contaminated by commercial yeast.

TEST 2. AIM. To do a test bake for the purpose of observing the relative differences in performance, speed, crumb structure, and taste, between Don and Yeast.
METHOD. Using Don's Vienna White recipe, a half (250g) batch of dough was made with each starter. They were mixed, autolysed, short kneaded, proofed, formed and final proofed as per the times and instructions in the recipe. Photos of the baking result are below :-

[img]http://www.sourdough.com.au/gallery/d/4174-1/Cooked+1.jpg[/img]
[img]http://www.sourdough.com.au/gallery/d/4176-1/Cooked+2.jpg[/img]
[img]http://www.sourdough.com.au/gallery/d/4178-1/Crumb+1.jpg[/img]
[img]http://www.sourdough.com.au/gallery/d/4180-1/Crumb+2.jpg[/img]

OBSERVATIONS/RESULTS. During the shaping stage I noticed the Yeast dough seemed stronger than Don, as in more "rubbery" for want of a better term. This is similar to the feeling I had the first time I baked this recipe using Don, having twice previously baked it with a sourdough starter.
The speed of Yeast, shown during the starter test, did not become noticable until the final 10 minutes of the proof after shaping, it was 5-10% larger than Don. This shows up in the photos of the baked loaves, though due to the slightly different shapes the difference is not as much as it seems.
As can be seen from the cut loaves there is no difference in crumb structure, and while you may be able to pick which loaf is which by the cross section shape, I defy anyone to pick which is which by the larger sliced pieces.
Four people did a blind taste test on these two loaves, no butter, just the plain bread. Result, no one could pick any difference in taste or texture in the pieces of bread that were randomly offered to them.
CONCLUSIONS. It would appear that my very first assumption may be correct, where I stated:-
1. An absolutely unique starter derived from Saccharomyces Cerevisiae yeast instead of the more common Candida Milleri yeast, without any of the characteristic sourdough flavours.

Based on the taste test, it would appear that I haven't been unduly harsh in assuming, prior to these tests, that the starter was contaminated with commercial yeast.
The taste results make me think that the starter "Don" is a Saccharomyces based starter, the speed result makes me think that it may be a "wild" variety of this yeast. The mystery remains "Where is the sourdough taste" or is the lack of it a feature of this type of yeast?