Google Ziets' Yeast and Sourdough Baking Page: Raisin Sourdough Rusks: Very Traditional South African Fare

Sunday, 18 August 2013

Raisin Sourdough Rusks: Very Traditional South African Fare

Ever had rusks with your coffee?

If you have been to South Africa or live there, you will know that these hard biscuits are almost inescapable. Together with coffee and biltong (beef jerky), rusks make up a full camping meal. Or a light breakfast.

I have reason to believe that these may have originated from dried bread supplied to the ships sailing around the Cape in the days of yore. Before refrigeration and the internal combustion engine. They would then naturally be part of the fare that the Voortrekkers of old took on their long treks in ox wagons into the harsh South African hinterland in 1838.

Light food to pack, if a bit bulky. But they will last almost indefinitely as long as you keep them dry.

Nowadays you find them in all grocers as well as most of t
he craft food stalls and bakers. And rusks are available in a myriad of styles.

The raisin water that started it all.

All using instant yeast or commercial yeast of some nature.

So I decided that it is time for some microbiology. An experiment to catch a yeast from raisins, then use that to make rusks in the traditional South African style.

These are called mosbolletjies, after the fermenting grape mush that they were first made of. The Cape had lots of grain and lots of grapes, even in those bygone days, so it was natural to use the fermented grapes in a sourdough starter.

I resorted to raisins. Bought them from my nearest grocer. Big mistake. It took almost a week before anything happened. Even after spiking the watery raisins with some brown sugar. Then it dawned on me that the raisin packers would take measures for the raisins not to ferment or go off in some other way. Therefore the raisins would be treated with a layer of wax after being washed, and possibly irradiated, to kill all germs, yeasts, bacteria and other flora generally mostly good for you.

Much volume after the first rise.

So I waited a bit more. My patience eventually paid off. There is no holding back of Mother Nature once she gets going. I saw some small bubbles forming. I waited another day or so, then fed the lot with about three tablespoons of stone ground, whole wheat, unbleached flour.

The results were immediate. Well, almost. The mix doubled in volume within three hours, so I added another half cup full of the same flour. This also took about three hours to double in volume.

Resting nicely after the first rise, looking just  enough.

At this stage I decided that I had a proper yeast. I split the mother into two, feeding each with a cup of flour and some water. Just enough to make a nice runny mix. These were left on the kitchen counter to bubble away merrily. Once these were lively enough to my judgement, one was promptly put in the refrigerator while the other went into my dough mix.

After reading The Bread Baker's Apprentice and Crust and Crumb, both by Peter Reinhart of the Fresh Loaf, I made up a dough with about 75% hydration. For this one I used two cups of rye, two cups of brown bread flour and six cups of white bread flour. Into this went about 40 grams of baking fat and two teaspoons of salt. Since this was to become rusks and not regular bread, I also added about ¾ cup of sugar. Rusks are supposed to be sweet, so I hoped for the best that the yeast will not consume it all!

Roll into small sausages. These differ from normal bread.
And of course, I would be remiss if there was no aniseed seeds in the mix. This was sorted by adding a royal helping of the seeds to the mix. The sourdough was added after mixing the dry ingredients thoroughly. The sourdough constitutes probably 500 ml of the water content, so I adjusted the rest of the water accordingly. This was mixed into the dough, adding the rest of the water. The molten dough was added after letting the basic mix rest for five minutes. No kneading yet!

After mixing the lot in, I kneaded the dough until it became silky to the touch, then left it to rest for ten minutes. The dough was still reasonably soft. This was patted with oil on the hands, then stowed in the large covered mixing bowl in the cold oven.

This lot was left to ferment overnight. It is really cold here at present, the day temperature inside the house being in the order of 17ºC/63ºF. So I reasoned that the dough will ferment slowly. I was right. The dough triple in volume overnight, which was good. The rest of the processing reduces the volume again, so there is time for a second rise.

Decent notes help to give you proper proportions of ingredients
This is where the making of rusks deviates from the bread making process. The dough is tipped gently out on to a floured kneading board and left to rest for twenty minutes. Then it is rolled into a snake just over 30mm thick (a bit over an inch for my other friends). This snake is cut into two inch sections , rolled into a ball , then rolled into a short sausage again before being stacked in a baking tin. This ensures that the pieces can be broken off after baking. Perhaps this is akin to making dinner rolls, except you pack these tight.

Leave these infant rusks to rise for another hour or so, until double the volume. Then dab some egg and milk wash on top before baking them at 175ºC/350ºF for thirty minutes. I spritzed the oven with water at the start, then twice again at five minute intervals. At twenty minutes I turned the baking tins around to get an even bake on the tins.

Pack tightly in the baking tray.  Neatness not really required!
At thirty five minutes the rusks were removed from the oven and left to cool. This part of the process is the same as for bread. The dough is still cooking for at least forty minutes after removal from the oven, as it is filled with steam.

Once cooled down, the rusks are broken apart and spread on a baking tray for drying. I dry mine at 125 175ºC/250ºF, just a tad over boiling point.  Two hours should see them nice, crisp and dry. This ensures good evaporation and some tanning to boot. We have no use for pale white rusks in this house! These are stored in a cake tin or plastic container away from humidity. They will soak up humidity like anything.

Especially coffee. They were designed to soak up coffee.

Voila, behold, your sourdough rusks!

Fully laden roaster
This was the first time I really paid attention to the relative quantities of ingredients in the dough. This is thanks to Peter Reinhart's admonishments! But jokes aside, I now am getting repeatable results. Predictable results, even without measuring internal temperatures or controlling the environment for any of the pre-ferment or the final proofing. It just shows what a little attention to detail can accomplish.

I would leave out some of the fat from this recipe next time I want to make rusks. Rusks are dry and as such will last a long time anyway. The fat will keep loaves fresh in bread form, so there is already a design difference. The rye also makes them a bit on the sour side, perhaps, so I shall leave out the rye altogether for rusks.

The rye contains less gluten than other flours and as a result you may find that the dough rises less than dough made with other flours. This will result in a more dense crumb. The extra density is not altogether unwanted in rusks. But the amount of handling and forming before the second rise will take care of that, resulting in a more dense crumb anyway. So the rye does not really add much to the end result.

Check for even baking, Wash with egg and milk mix.
Whatever you choose to do, these rusk soak up coffee as advertised and taste good too. Especially with the added aniseed flavour.

This post also linked to Yeastspotting!

Authored by Johan Zietsman.

Last updated on 2013-08-18
Break loaf into rusks after cooling, then dry them.


  1. snymanj15@gmail.com30 November 2018 at 06:43

    My mother used to bake boer rusks or "boere beskuit" that I loved. This was not a sweet rusk and you could have it with coffee, or pure water or just as it is dried out with butter on top! No sugar was added to this and because she used natural yeast it had a slight sour taste, which is perfect especially after it was dried to a slight brown colour.
    My theory for the name boer rusk is that it was named during the Anglo-Boer war. The wives in the farms baked it for their men on commando but the only had wheat, water and salt. (No sugar) So that is what they supplied the commandos together with biltong for field rations.

  2. Thanks for the nice reply Johan! We are eating a piece of history which appears to be almost unique to our part of the world.