The Fresh Loaf

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Kefir Sourdough Starter: initial observations and concerns

JonnyP's picture
JonnyP

Kefir Sourdough Starter: initial observations and concerns

Here is my experience with kefir as a component used in sourdough bread making.

Summary:  When adding kefir milk/curds/whey to my typical slow-ferment (no-knead) bread dough recipe, I find the quality of the gluten to be degraded: the dough tears more than stretches compared to if I use plain water instead. I suspect that proteases present in the kefir are cleaving the gluten strands.

Background:  I have been making bread dough using the "no-knead" method and the "5-minutes-a-day (refidgerated)" method, employing regular dry yeast (with proofing), instant yeast (without proofing), and sourdough starters (including my own local wild yeast starter and Carl Griffith's Oregon Trail Sourdough Starter).  I thought that adding kefir (instead of water) to my various doughs might add more flavor.

Method:  Using a 80% hydration ratio: 100g whole-wheat, 400g bread flour (13% gluten), I compared a loaf using 400g of water to another loaf using 400g of kefir milk/curds/whey, plus 50g of water (to account for the solids in the milk).  To these, I added 1/4 cup of my sourdough starter.  Primary fermantation of the dough (first rise) was done in my cool Michigan basement for 12 to 18 hours, covered in a plastic bag.  For baking, I used the preheated dutch oven method at 450deg for 30 min, then uncovered at 375 for 20 min.

Results:  After the 12 hour rise, the kefir bread dough did not seem "over-risen" compared to the control (water) dough.  However, using kefir instead of water seemed to degrade the gluten: the resulting kefir dough was much more prone to tear, and the resulting baked kefir loaf did not have the elastic crumb compared to the non-kefir (water-only) control.

Comment:  As far I know, there is no well-established historical cultural tradition of using milk kefir to leaven bread.  Although kefir might add more flavour than water, the resulting dough and loaf seem inferior to using traditional sourdough starters with plain water in the method described above.  There may indeed be an adventage in using kefir in fermenting/levening other types of bread (using different flours), or varying the water/kefir ratio, or using younger kefir or older kefir.  Such variables may be seen as either as a headache, or an opportunity to explore.  Because these 2 loafs were prepared and baked on different days, I plan to repeat this experiment under better identical conditions.  If there is enough interest, maybe I should post photos at each stage.

Until then, your kefir-levening experience comments/advice are greatly appreciated,

JonnyP

Mini Oven's picture
Mini Oven

Welcome to TFL!

I can't think of why it would leaven bread by itself, unless there was milk in the dough.  If the food for the kefir is milk sugar and one feeds it flour where is the kefir to find lactose to eat and release gas?   Have you tried adding milk powder to the dough?

Kefir and its byproducts would lower pH speeding up fermentation and the breaking down of the dough.  Your observations are correct.   Maybe adding ingredients to raise pH (like soda) would result in a base-acid chemical reaction releasing gas to raise dough before gluten can fall apart.  This is often the case in quick breads and cakes.  

It is my understanding that adding kefir and other fermented dairy products are used to get more flavor from a short rise.  Shorten proofing times and don't retard the dough waiting for it to fall apart.  Maybe it's not good to pair Kefir/whey with the 5 minutes a day formula known for long cold retardation.   You might want to post again on the discussion with the 5 min. Authors listed in the site search machine.  (if you want to capture their attention) 

FoodFascist's picture
FoodFascist

To my knowledge, you can't use any soda (bicarbonate or hydrocarbonate) in a dough unless you're making a soda-only bread as the alcaline soda will kill off any yeast in the dough and it will not rise.

MangoChutney's picture
MangoChutney

I am using kefir whey in my whole wheat sourdough bread, but not more than one-half of the added liquid volume.  Using 100% kefir whey did seem to result in a less desirable loaf but that was not a controlled test.  Many other variables were in play at the time.  I only bake a loaf of bread about once a week, so my experimentation goes slowly.  At the moment, I use kefir whey 50% by volume in the liquid I use to soak my flour overnight in the refrigerator, before baking with it the next day.  The other 50% is water.  The leavening portion of the recipe uses only water.  The final dough rises well.  I also usually pour some over the top of the loaf just before I bake it, and use that as the source of steam.  Last time there was not room in the pan because the dough had risen so well in proofing, and I was not able to steam it.  The oven spring was not so high as a result, but I do not interpret that as meaning that kefir whey enhances oven spring.  I mention it only in passing, in that the proofed dough had risen enough to prevent any liquid from being poured into the pan.  This means to me that the whey did not inhibit the rising.  The final bread is suitable for sandwiches, which was my intent.  It does bend around sandwich contents without breaking apart.  The other ingredients are only whole wheat flour, water, salt, and incidental oil from the rising bowl.  Oh, and some whole flax and sesame seeds.  Those tend to pop out while I am kneading the dough, but not from the baked loaf.

I used milk kefir in creating a sweet sourdough for cakes, cinnamon rolls, and the like.  This culture is now fed applesauce, milk powder, and flour, with the occasional bit of water to keep the consistency reasonable, and once some brown sugar when I forgot which culture I was feeding.  The other cultures that went into the making of this sweet sourdough were a bit of my wheat sourdough and some of my water kefir.  The nature of my water kefir culture changed some time back when I tried keeping it with a screened lid instead of covered with a cotton cloth.  It was in the room where I milled flour, and I fear it has become a substrain of my wheat sourdough culture.  It is quite yeasty now that the weather has warmed up, whatever it is.  It lives on brown sugar (sucanat), thus my mistake once when I was feeding jars in the early morning hours.

According to a list of species that I drew up from various sources, milk kefir has in common with grain sourdough perhaps nine species.  Most of what lives in milk kefir is not found in grain sourdough.  It would make more sense therefore to use milk kefir in a bread that contained milk as a major ingredient if one wants to use the biological aspect.  When judging the results, I think one should remember that adding kefir to a recipe will have the same effect as adding yogurt or buttermilk in similar amounts.  In fact, I substitute it for those things.

My theory is that natural cultures used in quantity, such as sourdough and milk kefir, have two sets of characteristics.  One is the biological, and the other is the chemical.  Adding a cup of sourdough to a recipe is the same as adding innoculants and also adding flour paste with flavoring.  Adding a cup of milk kefir to a recipe is the same as adding innoculants and also adding a soured milk product.

Kefir whey is a solution of albumin and lactic acid, among other things.  Lactoflavin is one of those other things, which is one reasons I drink kefir whey.  I would not expect it to be terribly active biologically in any sense useful for baking because most of the edible substrate is gone by the time you have produced whey.

Kefir curd is a pot cheese.  I would expect the effects of incorporating that into bread to be the same as for other pot cheeses, in similar amounts.  It makes a great low-fat spread for the baked bread, and an even better spread if you add 25% fat in the form of butter and olive oil.

Water kefir, however, should work as a leavening agent along the same lines as what they call yeast water.

 

leostrog's picture
leostrog

My conclusion is that perhaps the addition of a large amount of Lactobacilli may have a positive effect on the sourdough and the bread making process..

After receiving a new fresh batch of whey, I decided to try and add it to the sourdough. The whey was received after ripening of milk with my new Bulgarian starter – Lactina. This is the famous starter that is made from blend of local strands of Lactobacilli Bulgaris and Stretococcus thermofilis. The whey was added to my fresh sourdough – Finland type. The quantity of whey and rye flour matched the final result of 100% hydratation.

The sourdough with the whey was left at room temperature during the night – in the morning it was twice of its size, very”active” with lots of air bubbles. In comparison to its state before adding the whey it was a tremendous difference.

The technology was no knead bread and instead of water i used also warm, fresh whey with low acidity. The crumb had a very good structure.

clazar123's picture
clazar123

I make short fermentation sourdough and overnight-in- the -refrigerator (cold retarded?) fermented sourdough. I would concur that any long fermentation with kefir in the dough (but esp whole wheat) suffers a degradation of the gluten-sometimes.

I believe there are many people that have used kefir as a starter though I don't understand the dynamics of it.But ,then, it also works great to make a fast sauerkraut and it can ferment soymilk and nut milk! There is no lactose in those foods, either, and it produces plenty of bubbles in all of them!  

In the short fermentation loaves (dough not retarded) I have made, I believe it adds lift and tenderness to the crumb like any dairy but I haven't conducted any experimentation-just off the cuff observation.

http://www.thefreshloaf.com/node/13534/kefir-sourdough-starter

http://www.thefreshloaf.com/node/12751/kefir-sourdough-bread

http://www.thefreshloaf.com/node/12169/sourdough-and-kefir-good-or-bad-mix

FoodFascist's picture
FoodFascist

it worked perfectly well. I couldn't get the hang of making a sourdough starter to the usual recipe of, mix flour and water - leave in a warm place - add more flour and water - leave again - repeat - repeat. It either goes bad, or doesn't smell nice at the end, or won't rise the sponge properly.

So, having read in a Russian language source that Russian sourdough of the pre-bread industry era would usually have some sort of source of lactobacilli (milk whey, sour cream, kefir, etc.) I though I'd give my kefir grains a try. Knowing that kefir grains have many different species of bacilli and yeasts, I worked on the assumption that those species that can feed on flour, will, while others will just rest.

I chose grains over the end product - kefir - for two reasons. First, I didn't really want any milk products in my dough. I do make milk dough too, but for buns and pies rather than bread. Second, I thought it made more sense to work with the culture itself rather than with whatever bacteria will have ended up in kefir as who knows whether they all end up there, and whether the ratios of individual species are the same in kefir as in the grains.

As to MiniOven's question on what the kefir culture will feed on in the flour. It's not only lactobacilli that kefir culture contains. Kefir grains contain several dozen different species of micro-organisms, and the precise composition varies from strain to strain. Also, to my knowledge, lactobacilli can feed on sugars other than lactose (milk sugar), and I'd imagine they may also be able to feed on starches in the flour, especially when assisted by other species in the kefir culture.

I started with a heaped teaspoon of grains in approx 80 ml of a runny-ish mix of Allinson's Strong White Bread Flour (the only variety I had) and lukewarm water. Left it for 24 hours or a bit more. Than fed with some 250-300 ml flour and water mix (oops, overdid it a bit :-S ). That pretty much filled up my glass jar. Left for another day or so. After two days, the starter was quite bubbly and had a noticeable yeasty smell. It smelt a bit sour too, but certainly nowhere near as sour as maturing kefir. At that stage, I decided to try and make a sponge with it. So I strained out the grains and added a little more flour (can't remember how much exactly now as I wasn't writing it down). Sponge was ready after an hour or so. I added some polenta (I was making cornmeal bread), salt and olive oil and mixed it all up. But before I could add more wheat flour and start kneading, my toddler kicked off and I had to just leave it. By the time I put the little tike to bed, I was knackered and went to bed myself. I got up in the middle of the night, kneaded the dough, left it to rise and went back to bed. It was proofing from 5 till 8.30 am and in that time it more than doubled (probably more like tripled TBH). The final proofing took about 1.5 - 2 hours at roughly 18-20 C.

I was very very pleased with the resulting bread, it had lots of air holes, a crusty crumb, a very chewy texture (better than same dough using active dry yeast) and the crumb was, how do I put it, quite spring-y. I mean, if you press it between your fingers it springs right back. The taste was lightly sour but not overly so, I'd say typical sourdough (but I can only compare with commercial sourdough bread as I'd never ever made sourdough before).

The two main differences I noticed between this bread and the one made using active yeast are,

1) the crust is slightly drier, although after 3-4 hours on the shelf it has absorbed moisture from the air and softened.

2) the dough was stickier, but as I wasn't very precise with the quantities of wheat flour I may have used less flour than usual. I always try and make my dough as moist as possible, so even if it's still sticky, so long as I can handle it I don't add any more flour.

Overall, for me, this turned out to be a very easy, relatively quick and fool-proof starter. The main benefit is, I don't have to always keep a supply of starter in the fridge - I can just fish out a spoonful of grains when I need it and then return them to my kefir batch after I've made the starter. Which is perfect as I'm only baking 2-3 loaves a week at mo, this is the most I'll ever do, and there will be times when I won't be baking at all.

I didn't notice any deterioration in gluten mentioned by Jonny. The dough did tear a little when stretched to form a loaf, but so far as I can tell, not any more so than that made with active yeast. As I mentioned, I left the sponge and the dough for quite a while so it wasn't a quick rise by any rate.

IMO, using grains rather than kefir made all the difference.

It's also important to mention that commercial kefir, or that made with a commercial kefir starter, will be vastly inferior to that made with kefir grains. That's because commercial kefir starters don't have all of the species of bacilli found in natural grain culture, and hardly any yeasts. Besides, I suspect that commercial kefir is pasturised or otherwise treated before it hits the shop shelf, otherwise it's shelf life wouldn't be half as long as it is.

Because this was my first experiment of the kind, and because I'm really only a novice in bread baking, I didn't record anything or take any photoes. But since I'm so pleased with this first result, I'll keep experimenting with kefir grain sourdough starters, perhaps try larger quantities of grains, longer and shorter times to mature the starter, different flours, etc. and then blog or post the results in the forum.

JonnyP's picture
JonnyP

All advice above/below is greatly appreciated.  My takeaway summary of that advice:

1) Using large volumes of kefir is not recommended for long/slow bread-dough ferments.

2) Moderate volumes of kefir may be added for flavor in shorter bread-dough ferments.

3) Kefir grains may be used to create a pre-ferment that is successful in leavening bread dough.

Currently, my interest in kefir for bread-making is eclipsed by the wonderful aroma of my sour rye Polish borscht starter, that I made according to:  http://www.lthforum.com/bb/viewtopic.php?p=221326

More posts to follow.

JonnyP