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On Leaven, Sourdough, S'or and Hamets

Nearly all the bread I have eaten over the last 25 years has been wholegrain, sourdough bread. I believe this type of bread is tastier and healthier than most other breads, certainly far superior to the common white yeast bread sold in our supermarkets.

To be honest, though I have been baking bread for shabbath for some ten years, I have been "lazy" and have been using yeast to aid fermentation. My laziness perhaps results from the origin of my baking habit. It started as a father-son bonding thing with my youngest son, Aviel, then aged seven or eight. I didn't want to complicate things too much for him and even agreed to cater to his palate and bake with a mixture of wholewheat and white flour. We also used a bread-machine for the first knead. (Experience, the best of all teachers, later taught me that nothing beats hand kneading.)

Though a few years have elapsed since Aviel lost interest in our joint project, I continued baking -- with yeast. However all the time, in the back of my mind there echoed a mantra, "sourdough, leaven, s'or.

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Last Friday I posted the following status on my Facebook wall,

I finally did it! I've been meaning to do it for years and today I did it. I baked bread for shabbath without yeast. I used leaven, what the Americans call sourdough. It was spelt leaven in spelt flour.


Shabbat Shalom y'all!

Ches [the cohen] responded, "You still have to give some to me and my priestly brothers."

I retort, "Sorry -- merely 2.5 cups worth -- ALL MINE!"
[In other words, I didn't make a large enough volume to be obligated to give halah, dough tithe, to the cohen.]

Ches: "They closed that loophole somewhere around Menachot 64"

Me: "Maybe in the Bavli, but not in my Shulan Aruch! LOL"

My Facebook friend, Daniel, whom I have not yet met in person but he is on his way on aliya to live here with us, added:

Mazel Tov! I love the taste of sourdough. I have been been making bread of late using DADY, Dried Active Distillers Yeast. It was all I had in the house this past winter and I was snowed in. So I said why not? And it makes the best bread I have ever made. Super fast rise and a great taste. If you can get some, give it a try. I use it to make my special apple cider but I of course never distil. That would be illegal.

Ches I am also of the priestly brotherhood but I still set aside our portion. I would be happy to send you some.
[Ches and Daniel are now friends -- the wonders of social networking!]

I reply:

"Super fast rise" -- up here on my little hilltop I've got all the time in the world -- no instant gratification required here. It was good enough for my great-grandmother. And her little boy lived to over ninety before the Nazis and their lovers cut him short.

Rachelle enters the foray, "recipe please?"

I write this piece partly to satify Rachelle's request, though I am not sure that this is quite the response she is expecting. I do hope however that she and others find what I have to say here both useful and informative.

Recently we have been discussing baking techniques in my mishna and Minhath Hinuch classes. I have intended since before Pesach to write an essay on the art of baking "real" bread. These study sessions made me realise that most people do not understand what was involved in baking in ancient times. As a result, it is difficult for most to understand the halachic, legal ramifications presented in these learned tomes. I hope I can provide a satisfactory explanation of some of the concepts involved.

When we were kids back in Australia we were taught that on Pesach we must eat only"unleavened bread" (I know the terminology is the same in England), and that all leaven is prohibited, not just for food consumption but also re possession within your domain.

But no-one ever explained to us what these words mean. I think we thought that "unleavened" bread was some type of cracker. By extension the regular bread we ate all year round from Bronte Bakery was "leavened" bread. However Yemenite Jews have always eaten soft pitta style matsa and it is fairly obvious that our hagadah's narrative of the sandwich Hillel ate, is referring to a soft, flexible matsa. Conversely, many crackers today contain yeast or other leavening agents.

The truth is far from what we thought as children. The Torah in fact presents us with two types of prohibitions for Pesach. The first is to not eat hamets. An extension of this is the positive commandment that on the first night of Passover, we are obliged to eat matsa. Stay with me and I'll attempt to define exactly what hamets and matsa are.

The second prohibition is that we must destroy all the hamets and all of the s'or we own or possess. We are prohibited from retaining either. Our rabbis tell us that in fact there are two prohibitions here. If this is so, then hamets and s'or must be two independent substances.

The Mishnah teaches us that there are five grains. Hamets can only occur in these five species. These are: wheat, spelt, barley, rye and oats*. The common denominator of these five is that they all contain gluten. Thus, the Talmud informs us, rice is not a grain. When mixed with water, rice rots and does not ferment and therefore cannot be hamets.

By the technical definition, hamets is flour from any of the five grains, mixed with water and allowed to stand. After around twenty minutes, fermentation commences. Kneading the mixture stimulates the gluten (from the Latin word for glue) and prevents fermentation. Gluten gives dough it's elasticity and maintains its shape. As soon as kneading stops, fermentation restarts.

Adding yeast to dough converts the natural fermentable sugars in the flour into carbon dioxide and ethanol. These gases "puff up" the dough, allowing it rise further and faster. Thus adding yeast, dry or live, to dough speeds the bread-making process, though the yeast is not a fermenting agent.

As I wrote in my Facebook post quoted above, the use of yeast is relatively recent, first understood as a result of Louis Pasteur's work on microbes. Before this time, bakers used leaven (also know as sourdough, levain or a starter). Sourdough is essentially a piece of "old" dough in which a specific bacteria, lactobacillus, is growing. Each time you prepare a new dough, you retain a piece of it for another day's baking.

It is interesting to note that sourdoughs and other fermenting agents, such brewers yeast, are cultured sometimes for decades and even centuries. This allows a "good" strain to be developed and preserved. For example Carlsberg beer is still produced today from [the progeny of] the yeast originally developed by J. C. Jacobson in Denmark in 1847.

The Torah however tells us to take all of our sourdough, no matter how good a strain nor how well developed, and, once a year, destroy it in totality. As a result, on the day after Pesach, we must start again from scratch, to create a brand new starter.

I have asked a number of rabbis why the Torah would want this. Why in the whole world are fermenting agents developed to perfection over time and used for many years, but we must start again annually?

I think most of my teachers do not fully comprehend the processes involved, and as such they have difficulty in explaining the Torah's intention. I believe the answer is embedded within my question.

God wants to teach the Jewish people there is always room for a new, fresh start. We generally apply this concept to repentance on Yom Kippur, the day of atonement, when God forgives our transgressions, providing us with an opportunity to purify ourselves and to then start all over again. Pesach marks the formation of the Israelite national entity. A slave people is suddenly freed, to establish a new nation. But this freedom is not absolute. It is tempered. They will soon receive the Torah, the guide book on how this nation is expected to conduct its life in its ancestral homeland, henceforth and forever. Each year we take our haughtiness, represented by the s'or, and destroy it, declaring that we accept that our freedom as a nation is tied to our service to the Creator of the world, who has brought us home to this Land.

What happened to the Children of Israel when they left Egypt re provisions for their journey? Why were they unable to bake bread, a staple well known in the Egypt of the time, before they departed?

Baking bread with sourdough, s'or, requires planning, thinking ahead. The Israelites had to leave very quickly. They were very occupied on their last days in Egypt, preparing the Korban Pesach and "borrowing" valuables from their neighbours. Tomorrow's bread was the last thing on their minds. They were too busy to prepare ahead.

Each year we recall this by not eating hamets and destroying our s'or, eating the simplest form of bread, recalling our birth as a nation.

And now to Rachelle's question. I must be honest. I didn't prepare my own leaven this time. Preparing sourdough from scratch is on my to-do list. I was given starter by one of the growing number of bakeries in Yerushalayim who only bake with sourdough. I received mine from Tomer's Bread in Talpiot. They are happy to share their starters with the public.

Producing your own starter is quite easy, though time-consuming. You'll find many methods on the web, and also hinted in the Mishnah. The simplest technique is to mix up a dough, flour and water, and leave it on your kitchen bench for up to three days. The gluten in the mixture will encourage the required bacteria floating around in the air, to develop in the dough. It's a bit of potluck though. If it does turn out to be good, you keep going with it, growing and culturing it for the future. If it isn't too good, just start again. Like good wine and beer makers, the commercial bakeries have perfected the process. Just as today nearly all wines are fermented artificially and not from the natural yeast growing on the grape skin, so too bakers like to control their starters to ensure day-to-day consistency in their breads. Home bakers may care less about this consistency. After all, variety is the spice of life.

Once you have your starter, by hook or by crook, the process is similar to baking with yeast. About one third of your dough should be sourdough, the remainder flour, water, (a sugar -- I generally use silan, date honey -- though I want to experiment whether this is necessary) and perhaps a bit of oil and [sea] salt. Knead well. Cover and leave to rise for at least an hour or two. Punch it down. Form your bread. Allow it to rise again. Bake. I bake at 175° Celcius for about half an hour.

But now the real guts of the process. If you use up all of your sourdough when you bake, you'll have none for tomorrow or for next shabbath. Tomer, for example, gave me (for free) two little tubs of rye and spelt starter. You can only bake three times this quantity, not too much really. You must grow your leaven. Leave your mixture out overnight. In the morning add to the mixture up to the equivalent amount you have, of both flour and water. Mix well. Store in the refrigerator. The night before you intend to bake, again take out your starter and leave standing overnight. Use no more than half your quantity for baking. To the remaining starter, add the volume you just removed, of water and flour. Mix well. Store it back in the refrigerator. If you leave it out of the fridge without using it, the yeast may "overeat" the sugars in the flour and starve itself to death. The smell will change from the usual "sour" to something far more putrid. If this happens, throw it away and start again.

Based on my large reserve of experience, this is the sourdough story. I expect I'll learn a lot more as I gain more baking experience.

Good luck to anyone who wishes to try.


It is interesting to note that nearly all the bread and grain products (mincha, menachoth) baked in the Beit haMikdash, the Holy Temple in Yerushalayim, were not permitted to be hamets. The only exceptions were ten of the forty loaves of bread accompanying the Korban Todah and the two loaves of wheat bread brought each year on Shavuoth.

The lehem hapanim, the shewbread, placed on the Temple table each shabbath, was eaten by the priests a week later. This bread, though about eight centimetres high, was matsa, unleavened bread. The Talmud describes this bread as soft and fluffy. A mishna relates that a certain family had the concession for baking this bread. They kept their technique secret. Clearly they possessed a technology that we no longer know.

Menachem Kuchar, 15th May, 2011    

* Oats According to our sources, there are two main grain types: wheat and barley. The others are subcategories of these two, spelt being a type of wheat (today often referred to as 'primitive' wheat, being an older, simpler form) and rye and oats are sub-types of barley. It is clear that modern oats are not a barley. In fact the Rambam stated this 800 years ago. Our oats don't contain enough gluten to properly produce bread. Oats are very hard to knead. In Scotland (and this has spread worldwide) oats are used for porridge. As delicious as porridge may be, it cannot be compared to bread as a quality food. If you could produce bread or porridge, what would you choose?

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