The first criteria in judging sourdough breads is that they must display authenticity. Because there are no legal or even trade agreed standards, yet it is clearly understood in the wider (world) context, what constitutes a genuine sourdough, it is important that Australian judging standards accord with what is understood internationally.
Sourdough breads are clearly made without bakers yeast. This must be the first criteria. This regulation must be stated as a standard for entrants. The starter culture also must not be made with any bakers yeast, at any stage. It must be called into question whether the sourdough “powders” available actually initiate a sourdough, or are mere flavouring agents. As none seem to contain anything like the polycultures which have been identified in genuine sourdough bread, how they could then enable a sourdough needs clarification.
Because bakers yeast is used widely, and often put in what is purported to be a sourdough bread, there should be a category for a “semi-sourdough”, which may have a proportion of bakers yeast, but which should clearly, by organoleptic and structural criteria,be different from a conventional yeast bread, with overt characteristics of a sourdough.
(1) Structural criteria of sourdough
“Good looking bread is not always good bread”(Bernard Ganachaud)
“Bread is both an architectural and a gustatory phenomenon”(Steven Kaplan)
Because sourdough is generally a hearth or sole baked bread, the loaf must display skill in this modality. It should be well risen, and slashed appropriately to accommodate oven spring, both technically and creatively. That is, bursting is undesirable, the spring should be confined skilfully to the cuts or slashes. These should display some creative characteristics, and boldness.
The moulding of the loaf must also be skilful, although not technically perfect, as this is too structured for a sourdough, which should display character. Exterior moulding signs are less desirable, as the dough should be well fermented, which will decrease obvious moulding marks.
“Bread is one of the rare foods which is not picked up with a fork….by touching, breaking and feeling bread, the fingers participate in assessing the quality of its crust and crumb”(Kaplan)
The crust should be well developed and attractive, with bloom (colour) indicating both good fermentation, appropriate flour and creative baking. Wise choice if flour will enable good bloom. The use of steam in baking should be appropriate, with highly glossy crusts less desirable. A thicker crust is desirable, as this is a “crusty” bread. This crust should have good edible texture, and not be leathery from too much steam.
Internally, the structure should display bold and adequate fermentation, with irregular alveolation, interspaced with dense crumb. Good fermentation is evident in a shiny internal surface of individual alveoli. The aeration should not be overly irregular as this is not sensible eating quality, with butter or spreads simply “leaking” this sort of aeration is more suitable in a baguette, rather than a loaf. Over irregularity is also technically faulty, in that the moulding has not sufficiently redistributed the gases.
The internal crumb should have some colour, indicating both good flour and possibly a blending of flours to enhance the loaf’s character. This should also be a facet of the reflection and capture of light.
The crumb should tear well without easily forming small crumb, or damaging the structure.
The crumb should be springy and resilient while still dense, but not damp.
(2) Organoleptic criteria for a sourdough
“The deeper and truer reality of its smell, its taste and its consistency-that is its flavour” (Calvel)
A cognitive structure as in wine assessment is required. Bakers and judges should articulate their criteria, rather than talking in uncorresponded generalities. It is difficult to distinguish between tastes and smells. The organoleptic evaluation should discern harmony between these two faculties as a primary objective.
The primary aromas may be from the crust. Grilling, roasting and caramelisation, even chocolate, and possibly frying analoges obviously dominate. The next most reported are of “nuttiness”, referring to hazelnuts and almonds and often butter. The taster should evaluate the balance of these, and be free to make associations with the familiar. What is important is the synergy displayed, and the strength and intensity of aroma.
The crumb will exhibit a wider range of aromas. which will in a sourdough, be underscored by acidity. Lactic is more skilful than acetic, and while maintaining the “twang” of a sourdough is important, attenuating acidity is desirable. The development of fruity and floral aromas is characteristic of a good sourdough. These range from dried fruit, honey, spices, herbs and extend to buttery and farinaceous (cooked cereal-oat porridge). It is important that judges attempt to access these aromas, and record them. This is part of the evaluatory structure which must be developed, and is as viable and possibly more far reaching than oenological assessments, and should include parameters celebrated in wine tasting.
This is possible because the advanced fermentations of sourdough enable the liberation of all manner of aromatics in the bread, released from the wheat matrix and volatilsed, and are hallmarks of appropriate fermenting (as in wine…and cheese). Such criteria are not appropriate with yeast breads, or erzatz sourdoughs, as the fermentation does not proceed past inflation generally, and acidity is not developed.
All of the characteristics mentioned, and more, are evinced by the crumb as it is chewed. A major criteria here has to be the length of flavour…how long it actually lingers, and how it changes or develops. Lengthy, lingering taste equates to quality. The mouthfeel of a sourdough must be of creamy softness, it must dissolve after minimal chewing and be easy to swallow and digest. The redolent creaminess exposes the quality of the acidity, and it is here that often the clear taste of wheat and perhaps other cereals such as buckwheat or corn is liberated, and lingers .
Any artisan or sourdough bread must have character of appearance, structure, taste, aroma, mouthfeel and be tactile. The category is defined by these really, as made not by the uniformity of machines or factories, but demonstrating the hand made quality.
The Natural Tucker Bread Book 
by John Downes
Hyland House Melb. 1983.
Artisan Baker Association (ABA)
Email. firstname.lastname@example.org 
Web. www.artisanbaker.com.au