Sour dough: leaven refreshment, and ash content

Hi,

I have moved this over from a discussion on Shiao-Ping's blog  to my Blog, as I was getting lost in some of the detail being covered, and because Shiao-Ping had asked me for more detailed discussion of sour doughs within My Blog page; so, here goes:

I am detailing below the feeding regimes we used to make thousands of Pain de Campagne and Rossisky loaves everyday in the bakery where I worked from 1994 to 2003.

Feeding regimes:   Commercially one feed works fine

e.g. French Leaven was refreshed from 41kg to 130g every 8 hours.   We had 3 bins this size, enough to make 6 x 120kg of dough for pain de campagne, with 3 sets of 41kg of leaven left for refreshment, which would take place 4 to 5 hours later, given our leaven fermented in 3-4 hours.

FRENCH LEAVEN REFRESHMENT

 Occasionally we had to let a batch of leaven go really sour, or, add some rye sour into the leaven as we worked the leaven so hard that the acid content had fallen way down; a rare problem indeed for the home baker, I suggest?

Shiao-Ping, thank you for your most recent reply making reference to LeFleur, Kamir and Leader.   How ironic indeed that our French leaven as discussed above needing an injection of acid bacteria, whereas LeFleur and Rubaud both reject the premise.   I happen to think it really depends on how you look after/mistreat the leaven in its non-production phase.   Commercially, this phase is very short, but for the home baker that will not be the case, unless a constant refreshment regime is applied, and a considerable amount of regenerated leaven will then have to be thrown out as waste.   Don't you think the magic of maintaining a living culture to raise all your bread over a long time period is some really special concept?   Unless I was thinking my levain had genuinely gone bad, I'm with Hamelman all the way; but if the base is "off", it has to be thrown out, and a new leaven created in its place.

1 bin of Rye sour comprised 18kg of flour and 33kg water, and just 2kg of original sour; on flour basis this means 670g of fermented flour being used to ferment 18kg of flour [i.e. 3.72%]!!!!   After 2 hours the fermenting rye mass would be bubbling up at the top of the bin.   When we used the sour after 18 hours it would have dropped right back and the colour changed from the grey of dark rye to a pinkish brown tone with an obvious creamy texture, and the residue of a thin yeast crust on the top.

RYE SOUR REFRESHMENT

For the home baker life has to be a bit more complicated in that most bakers will use a mother which is retarded in the fridge between baking sessions.   That said, when it comes to refreshment for baking, I build enough leaven to have some left over which will then go back in the fridge ready to make the next leaven.   I do not keep a pot of degenerating rank sour in the fridge, as that just becomes an acid bath in which no wild yeasts can survive.   If you do this it will take an aeon and a fantastically complicated feeding regime to bring the leaven back to a suitable state to make good bread.   To this end, I agree wholeheartedly with Shiao-Ping on leaven storage.   The mention of German bakers using  sour for flavour purposes only, maybe needs the additional reminder that commercial yeast will then be added to the final dough to counter  the inability of the wild yeasts to prosper in the high acidic environment.   Only keep a small amount of stock, and make sure to keep it relatively fresh.   Yes, it is possible to bring very old leaven back to life and make bread relatively quickly; but I would argue that bread would be poor in quality.   A small amount of relatively decent leaven can be fed carefully to produce a fully balanced culture which will yield the BEST bread; this is what we strive for.

When all's said and done the state of the leaven needs to reflect your own palate in terms of the eating qualities of your bread.   A leaven made with just one refreshment of a chilled pot of acid will give sour bread.   A leaven which is "green" will produce bland and low volume bread, as the yeas activity has not kicked in properly, and insufficient time has elapsed for a build up of any lactic or acetic acid

Please read what Jeffrey Hamelman says in his section on "Detmolder" [pp200] of "Bread: A Baker's Book of..."   It gives real context to the need to create the necessary balance of acids and wild yeast.   Other than that most other references are academe.   They are of great interest and make very challenging reading, but with reward.   I think Shiao-Ping would agree with me that the work of Debra Wink on this site is by far and away the best starting point for digging deeply into this complex area.

I'm still trying to make sense of a comment made by Hansjoakim concerning high acid concentration and low pH.   For Hans, wild yeasts don't like high acid concentrations but don't mind low pH.   To me, the wild yeasts are just as sensitive to acid concentration as lactobacillus, if not, even more so!   Shiao-Ping is under the impression that a low pH indicates high acid concentration; that these are one and the same thing.   I would totally concur with this.   Saacharomyces Cerevisiae [Baker's Yeast] does not like acid conditions at all, so plays a very limited role in this type of baking.   There are a number of other yeast strains which can tolerate more acidic conditions, but I would suggest that is still over 5 on the pH scale.   Working with pH is incredibly interesting; we did some experimentation whilst I was at College, but it would require tremendous dedication to the cause to do it in a home baking context.

On that note Shiao-Ping is bang on the money in her discussion of "balance".   Yes, a feeding regime can be just a guideline; but it will only work in this way when the baker understands what is needed from the leaven and how to create the conditions that will deliver that.   The reference to rhythm is all important.   A long-time baking colleague and friend of mine once wrote a small passage explaining how we used to hand knead all our dough in the small bakery he and I set up and ran over 20 years ago.   He came up with the monumental phrase "be the dough".    In that sense the dough really is what you put into it, in terms of energy, and on many different levels!!

Hansjoakim makes reference to high ash content/extraction rate in flour.   This definitely impacts on fermentation.   I have more direct experience of this with regard to the more conventional bulk fermentation systems.   Wholemeal and brown doughs will not tolerate long fermentation in the same way that white flour doughs would.   I think this is the real basis to the French ash content system.   In the UK we don't really have anything industrially to compare with the Type 65, and 80.   I suspect the American way to deal with this is the same as we do in the UK.   That is to add in a portion of wholegrain flour to conventional white bread making flour.   This may be either strong wholemeal flour, or a dark, or, medium rye flour, or a combination of both.   I notice a lot of folks on here use "AP" flour.   We have "Plain Flour" as the nearest equivalent, but I would not look to use that myself; it is designed for home bakers making pastry and cake.

My favoured alternative to the wonderful all-Canadian strong white flour I have sourced is from the following places.   There are some wonderful local farmers/millers who produce an equivalent of this ash content, and it is great to make bread from these organic and sustainably produced strains.   For all that, our climate in the UK is rubbish, as many of you will no doubt know.   A local miller who has supported me by coming in to lecture to my students grows single strain rare breed organic wheat on his own farm, milled at his own brand new, but traditional, stone grinding mill just 3 miles away from the farm.   His flour has quite a high protein content, and it can be used to make great bread, through long fermentation.   For all that the gluten quality is, to me, very low in comparison to the strong flours derived from Canadian and North American climates.   That has to be expected and accepted when taking the decision to use these flours.   The English climate is what it is, and these wheats have been grown in a non-intensive and environmentally sensitive way.

Best wishes

Andy