Anybody used sourdough yeast for beer ?

[bobukbrewer]

Two months ago I made a starter from organic wheat flour, and since then have made quite a few very nice loaves - I was wondering if I could make a pale SMASH beer using this yeast ?

 

[chthon]

Does it contain lactic acid (does it smell fruity)? I have once made a beer with a sourdough starter, but the real yeast had the upper hand. So I had a normal fermentation, nothing sour. I got an apparent attenuation of 70%. And it tasted like good beer.

 

[bobukbrewer]

unless lactic acid is a by product - no
there would be NO real yeast in the brew

 

[phildo79]

Think I remember reading in a Papazian book that you can make beer with bread yeast but you need to use absolutely loads of the stuff for it to work. Think it might have been a technique he stumbled upon whilst travelling around Europe (possibly Scandinavia).

 

[MarkBowie]

Yes you can do it, but it isn’t as simple as chucking in your starter from the fridge. It needs to be a productive starter from the fridge and you need to take some of your starter from the fridge and produce another in a separate container as you would with a beer yeast. Step it up with similar quantities as you would have done to produce your sourdough starter and then you will be left with viable yeasties for the beer.

For the other question - there is a lot of lactic acid present in your starter, it’s a natural byproduct of sourdough yeast. It also acts as a natural preservative; it’s the black layer of liquid that separates out from the starter if you leave it in between uses.

 

[Graz]

Don't know about home brewing with it but I have made sour dough bread in the past and have also had a bottle of this from the Wild Beer Company: https://www.wildbeerco.com/item/277/Sourdough.html

Tastes like sour dough bread funnily enough. From their description sounds like a lot of effort for a beer that I though was okay but nothing special.

 

[StFlipper]

There's also the complication that a sourdough starter/levain isn't only a yeast. It's a symbiotic culture of a bacterium (lactobacillus) and a yeast, where the lactobacillus breaks down starches which the yeast wouldn't otherwise be able to ferment, end produces lactic acid in the process. The mix of starches and sugars in malt is going to be very different from that in flour, so the result will unpredictable. I can imagine that the lactobacillus might not find starches to its taste, so might not produce the lactic acid which is presumably part of the intention.

A local baker near us tried their hand at sourdough a few years ago. However they used the same basic dough formula they use for a standard farmhouse loaf, adding some sugar to the mix, which bread yeast fully metabolises. Unfortunately their sourdough just came out slightly sweet as a result so it seemed that the sourdough yeast couldn't do anything useful with the sugar.

 

[StFlipper]

Just reading the Wikipedia articles on beer vs bread yeasts. Apparently "baker's yeast" is S. cerevisiae (Saccharomyces cerevisiae), the same basic type as a top-fermenting ale yeast, and historically bakers got their yeast from brewers. However that yeast type isn't generally present in a sourdough culture ("Investigations of wheat sourdough found that S. cerevisiae died off after two refreshment cycles") when S. Exiguous usually takes over.

It seems that S. Exiguous is "maltose-negative", whatever that means, although by coincidence here's someone's research paper about fermenting an alcohol-free beer using a "maltose negative" yeast. According to the research paper the maltose negative yeast is used "due to its complete or partial inability to convert maltose and maltotriose into ethanol".

So it's just possible that using a normal "Type I" sourdough culture could result in an alcohol free beer, with some lonely lactobacillus floating around looking for something to eat.

 

[chthon]

I had a sourdough starter that contained only yeast: it mostly smelled like bananas. It was made of rye flour. It's only since a couple of months that I finally have a sourdough starter with lactobacillus, it smells fruity. Other evidence that my first sourdough starter really was yeast, was that the beer fermented with it, absolutely did not have any sour tones. It just tasted as good beer.

 

[StFlipper]

I had a sourdough starter that contained only yeast: it mostly smelled like bananas. It was made of rye flour. It's only since a couple of months that I finally have a sourdough starter with lactobacillus, it smells fruity. Other evidence that my first sourdough starter really was yeast, was that the beer fermented with it, absolutely did not have any sour tones. It just tasted as good beer.

Which seems to fit in with the article saying that the original S. cerevisiae tends to die off after a while once the culture becomes acidic.

My sourdough culture is now 8 years old, and most weeks I make 2 loaves of bread with it, refreshing the culture at the same time. I think that a fruity smell only tends to come out if the culture is left a long time without a refresh, when the lactobacillus starts to dominate the yeast (which has fermented to completion) and there's a watery layer of lactic byproducts on the surface. With a refresh once or twice a week the culture smells sweet, and not fruity at all.

The first time I attempted a sourdough starter I followed the instructions in some artisan bread cookery book, which claimed that you'd have a viable starter after 3 days, even if it didn't look like it was very active. Load of rubbish. The first loaf I made came out smelling of stuff you clean out from under your toenails, and hadn't risen at all.

The instructions here (http://www.thefreshloaf.com/node/233/wild-yeast-sourdough-starter) worked very well for me. I started with some locally grown wheat grain, ground into a rough flour, on the basis that you want to encourage whatever yeasts are present where you live, which will vary from area to area.

 

[chthon]

I have made sourdough starters from different kinds of milled grains. The one that smelled foulest was one where I had also used oats. Others made from wheat flour and rye flour were mostly more pleasant. But yes, seems the best thing is to build a first starter at least one week so that the good organisms have time to grow and replace the more smelly types.

 

[MarkBowie]

It’s good to hear so many other people are making proper bread. I just use rye flour for my starter as I heard it was more stable.