The Fresh Loaf

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Feeding Rye Sour

byomtov's picture

Feeding Rye Sour

I have prepared a rye sour according to the instructions in Ginsberg's Inside the Jewish Bakery: Rye and Other Breads.


He says that, once established it should be fed once or twice weekly, but does not specify the procedure. Is it just the same as the daily feeding that creates it over 10 days?


That would be:



Sour 85g (discard excess)

Flour: 70g

Water (90F) 55g


PM: Same as above except use 200g sour from AM feeding.

Ilya Flyamer's picture
Ilya Flyamer

I would use a much higher ratio, i.e. more flour relative to starter. I maintain my rye starter by feeding it around 1:10:10 (e.g. around 5 g starter to 50 g flour and 50 g water) whenever I need to bake, using up most of it and placing whatever remained on the bottom in the fridge.

alcophile's picture

I use the same feeding as Ilya does, 1:10:10. I also store in the fridge and feed about every two weeks. Earlier this year, I had six weeks between feedings and suffered no ill effects on the one-year-old sour.

In Ginsberg's The Rye Baker, he uses the 1:10:10 feeding for his starter, slightly different than that described in ItJB.

rondayvous's picture

Sourdough starter, Rye sourdough starter, Rye sour.

While I don't have "Inside the Jewish Bakery" I do have "The Rye Baker" Where on page 35 he starts a 3 page description of "How to Build a Rye Sour Culture" as a sub-heading of "LEAVENING".

In my opinion, CLAS is a rye sour. What Reinhart is describing in his book is rye sourdough.

If you are leavening the dough with fermented rye, it is sourdough. If you use fermented rye to reduce the acidity of your dough, it is a rye sour.

The only reason I am making this distinction is to avoid confusion about feeding schedules.

Reinhart said in "The Rye Baker" rye sourdough should be fed a few times a week. He went on to say that sourdough fed daily performed better than dough fed a few times a week.

A rye sour, on the other hand, can be kept in the fridge for a week or two ( based on my experience) with no ill effects.



Ilya Flyamer's picture
Ilya Flyamer

I always thought "rye sour" was a synonym for rye sourdough starter. Is it not? Do you change the name depending on the function, whether it's just used for the acidity, or also for leavening?..

rondayvous's picture

I'm not entirely sure if the distinction is generally accepted (hence the qualifier "in my opinion.")

But it certainly makes sense to me that we wouldn't use the same language to describe two very different ingredients. One that is used to leaven (and provide acidity) and one that is used solely to acidify and add flavor the dough.

squattercity's picture

Just to keep the confusion going: in many of his replies to comments on TheRyeBaker site, Stanley Ginsberg says that, in his recipes, 'rye sour' means rye sourdough starter.


alcophile's picture

I believe we're splitting the hairs on the heads of the microorganisms, if they had any. It's a matter semantics; they're all sour cultures. Ginsberg discusses the four types of sour cultures on p. 50.

  • Type 0: Commercial yeast; yeasted poolish, biga, etc.
  • Type I: Sour culture; balanced LAB and yeast, medium acidity
  • Type II: Sour culture; mainly LAB, high acidity
  • Type III: Sour culture or LAB culture; used dried as acidifier

The recipes in TRB use type 1 rye sponges and some type 0 wheat sponges.

His Starter Sour instructions on p. 35 use daily feedings to create the initial sour. His Maintenance Refresh on p. 37 can be stored indefinitely in the fridge. He does say that he usually feeds his maintenance sour once or twice a week and he refreshes <36 h before using in a recipe sponge. But it can be stored for much longer periods between feedings (my own empirical evidence).

KMKZ (aka CLAS—Concentrated Lactic Acid Sourdough Starter) is probably a Type II rye sour culture and has no leavening power:

A flourless rye sourdough (aka sourwort, FLAS) has been discussed here:


rondayvous's picture

The heading to that passage (The Rye Baker:Ginsberg) is: Predoughs: Preferments-Yeast AND Sour Sponges. He made a point of differentiating between Yeast sponges and Sour Sponges. What he did not do, however, is identify which was which.

When Baking with rye, this distinction is important because the dough's acidity is critical to the successful production of rye bread.

As for splitting hairs, as I explained when I gave my opinion, I defined a term in order to make an important distinction when discussing refresh intervals.

No hairs were split. I simply defined a term to clarify a comment. IMO, when talking about rye bread, it is important to make a distinction between leavened starters and acidifiers. Since one requires regular maintenance and feeding and the other is pretty much made as needed.

I love rye bread, but don't make bread often enough to try and keep a pet (sourdough starter). Since it is not necessary to keep a pet to enjoy all the benefits of good soured rye bread.

alcophile's picture

From p. 50 in TRB [emphasis mine]:

Microbiologists who study sourdough fermentation classify sour cultures into four types, shown below.

What follows was the table that I summarized above. Yeasted sponges are still sour, but they have relatively low total titratable acidity.

I'm confused. How do you acidify your rye breads if you dot no use a rye sour culture? The sour culture that Ginsberg maintains is the same as a 100% hydration Type I rye sour sponge. Hamelman instructs to remove a portion of the sponge to reserve for the next bake. But he had to have a rye sour culture to inoculate that first sponge.

rondayvous's picture

I've lost count of all the mistakes I've found in his book. This one is obvious on its face. A commercial yeast fermented bread doesn't fall into anyone's definition of a sour culture.

I suspect he should have said leavening agents.

alcophile's picture

I don't believe this one is a mistake. Ginsberg's table appears to be verbatim from his footnote 59. One of the authors (Ganzle) is often mentioned here on TFL in relation to sourdough. Here is another reference ( to type 0:

At the same time, some researchers also considered another type of sourdough as type 0, referring to pre-doughs or sponge doughs, with addition of baker’s yeast (Saccharomyces cerevisiae) [5]

A straight dough will have a different flavor than a bread made with a type 0 sourdough, or pre-dough. That doesn't mean the final bread will be sour. Even breads made with type I sourdoughs can be made more or less sour by tweaking the inoculation amount, time, and temperature used for the pre-dough.

rondayvous's picture

I’m sure you didn’t mean to reference a source to validate itself? The link you provided seemed to be under the false impression that the bacteria in sourdough magically appeared from the environment. while environmental bacteria can be a factor it is not the primary source.


mwilson's picture

Seems like there is some contention here! Clearly not a mistake though, I agree!

Sour is the undeniable and inevitable end of any flour fermentation! Even if seeded with baker's yeast, which is simply a more refined and more industrialised way of using brewer's yeast / barm.

LAB are stimulated by the presence of any yeast ferment and have been shown to grow to a microbial population that matches a typical SD starter within 24 hours.

But as said earlier, the TTA will likely be much lower compared to a cultured (SD) starer.

The term ‘sourdough’ ultimately gets it moniker from when dough likely seeded with an exterior culture, such as brewing beer was seeded to make a leavened dough, for which a piece reserved would then ‘sour’ and be used to seed another batch of leavened dough.