The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

commercial bakers yeast starter vs. sourdough starter

brendateese's picture
brendateese

commercial bakers yeast starter vs. sourdough starter

I got interested in using a starter for breadmaking several months ago.  I sent for a good sourdough dry start through Friends of Carl (Oregon Trail Sourdough) and while I was waiting for it to arrive set myself up to learn the process using commercial bakers yeast.  I use regular dry yeast, not instant dry yeast. 

I was very happy with the result!  It worked well for a long time, until suddenly it didn't.  My yeast starter started going down and finally dying.  I had to re-start the starter from scratch 3 times, each time it lasted a shorter period of time.

I think I thoroughly understand the requirements of proliferating yeast.  I've read widely on this site and elsewhere.  What I'm wondering is this, and this is my question today  --  could it be that keeping the starter in the refrigerator is part of the problem?  I bake only 2 - 3 times per week, so I keep the starter in the refrigerator, taking it out overnight to refresh before baking day.

Although, come to think of it, sometimes I don't do this.  Sometimes I decide to bake in the morning and just remove a cup of starter for my bread, refreshing the starter and returning it to the refrigerator after an hour or two.  Is this part of my problem? 

The commercial yeast starter was wonderful when I first set it up, very tangy in smell and taste, very bubbly and active after refreshing.  But the new starters have never been that good, even though I am careful about hygiene/prevention of contamination/using a perfectly clean mixing bowl and cover.  I experimented with different kinds of covers and I use glass bowls.

Any insight would be appreciated.  Now that I'm having this kind of trouble keeping the commercial yeast starter going I'm afraid to start my sourdough.  I've had the dry start from Friends of Carl for several weeks and I don't want to waste it if I don't have my technique down right.

 

 

jcking's picture
jcking

What and how much of each ingredient (please be very specific) goes into this commercial starter?

Jim

brendateese's picture
brendateese

thank you for your interest :>)

10 oz. water

1 2/3 c. AP flour, fluffed and scooped, not sifted

1/2 tsp active dry yeast

Doc.Dough's picture
Doc.Dough

you need to become familiar with two concepts:

1. exponential growth

2. temperature sensitivity of growth rate

i suspect you are not allowing the starter to grow long enough to replace what you used before refrigerating it; and you are not letting it grow in the refrigerator long enough to make up for the first error.  just let it grow until it starts to fall before refrigeration then feed it at least every five days in a ratio of 1:5:5

brendateese's picture
brendateese

ok this makes sense to me.  

I think your suspicions are absolutely on the mark 

many thanks for your analysis, you are a terrific teacher

brendateese's picture
brendateese

one last question about the ratio 1:5:5

that would be the same amount of flour as water, by weight I am assuming.  but what about the yeast?  how much yeast would you put in for, say, 2 cups of flour?

Chuck's picture
Chuck

I too think that using and using and using and using without allowing enough growth to completely replace sounds like a  reasonable guess as to what the problem might be.

What I really want to know now is what happened? Did allowing more growth (for example by leaving the "starter" out of the refrigerator for a longer time) solve the problem?

jcking's picture
jcking

A rough calculation (converting everything to weights) gives the starter a 120 to 125% ratio of water to flour (hydration). This would indicate to me the starter is a poolish. Do a search of poolish (here, upper left) for more information on care, use and maintenance of a poolish.

Jim

brendateese's picture
brendateese

yes, the starter is a poolish.  Sometimes I use it straight up to make pancakes so I like it a little on the thin side.

Jim, I have read up on poolish and I'll review it again.  But for now, could you tell me about how much yeast you would add for about 2 cups of flour in the starter? 

jcking's picture
jcking

I need to know what the goal is. 2 cups of flour to how much water? Weighing would lead to the greatest accuracy. How much poolish is needed? How soon will it be used? At what temperature will the poolish be kept?

In general a poolish is not refrigerated. Perhaps someone with experience refrigerating a poolish could chime in.

Generally a poolish is equal weights of flour and water.

In general at a room and ingredient temperature of 72 ~ 80°F, based on the weight of flour at 500 grams (3 to 3 1/2 cups);

3 hours = 1.9 grams, rounded 3/4 tsp ADY (active dry)

6 hours = .9 grams, level 1/2 tsp ADY (active dry)

12 hours = .4 grams, level 1/4 tsp ADY (active dry)

Longer times and or a stay in the chill chest and you're on your own.

Jim

brendateese's picture
brendateese

This is very good information for me and I appreciate the time and energy you took to bring me up to speed.  I'm starting to realize some of the problems I've been courting and hopefully I can use your elucidation of starters to improve my act.

Doc.Dough's picture
Doc.Dough

I think you are making a poolish but treating it as a starter and feeding it repeatedly, taking out what you need for the current batch then refreshing it again.  Is that correct?

The ratio 1:5:5 is based on weights of starter:water:flour, so if you are feeding prior to storage you might mix 10g of starter, 50g of water, and 50g of flour; stir it up and let it sit at room temperature for two hours then refrigerate for no more than five days (actually if you plan to leave it in the refrigerator for a full five days I would suggest a 1:10:10 refresh which allows for one more doubling while in storage).  At that point you would take it out, let it come to room temperature and see if it is still active by watching to see what it does.  If it begins to rise, let it go until it crests before feeding it to make your next batch of bread. If it doesn't rise at all, feed it and let it sit at room temperature until it crests, then repeat the feeding cycle before using it for bread. You may choose to multiply it up in smaller increments (1:1:1 or 1:2:2) or you may choose to keep a smaller amount in the refrigerator and grow it in stages of 1:10:10 when you want to bake.  If you bake more often than once a week, you may find it easier to just leave it out and feed it twice daily at 1:6:6 for a 22°C room temp or at 1:2:2 for a 20°C room temp (you can see how sensitive it is to room temperature)

brendateese's picture
brendateese

I am making a poolish and treating it as a starter etc.

Sadly, this may be all I am capable of.  But OTOH  --  even this crude method is improving my bread wonderfully!  If only I could keep the starter going I would be satisfied, and I think you and Jim have given me enough information to do that.

"The ratio 1:5:5 is based on weights of starter:water:flour... "  --  oh, now I get it.  This is a recipe for refreshing the starter, not for starting the starter. 

I've copied out your very kind detailed reply and I will pay much better attention to these details to keep my starter active.

many thanks for sharing your knowledge, I will put it to good use

Chuck's picture
Chuck

...even this crude method is improving my bread wonderfully!

It sounds like you're in a position to make a complete comparison taste test. You have/can make all of: i) yeasted bread, ii) "starter" built with commercial yeast, and iii) wild yeast starter. Too often I hear semantics/theory/wordpolice about whether something built with commercial yeast is "really" starter, or bread using it is "really" sourdough. I'm much more interested to learn how does each one taste (and any other things that you notice comparing using the starter made with commercial yeast to the starter that relies on wild yeast)?

brendateese's picture
brendateese

-- when I first started playing around with a commercial yeast starter, I was getting results that seemed to me like "real sourdough".  The smell and the taste, it was sour and tangy and the bread was really something.   I knew from my reading that this couldn't be anything like the real thing, not real sourdough.   But it was close enough for me, and I thought I might not be bothered getting a real sourdough dry start, commercial yeast was getting the job done. 

I really thought then, and still do  --  completely uninformed opinion of course  --  that the crucial thing is to have fermented flour.  It could possibly be the fermented flour taste, not the specific yeast organism that is important?  At least to me?  And my family, who enjoys my new bread also...

But as you can see, I ran into trouble through not understanding enough about what I was doing, so had to come and sit at the feet of the masters for awhile.  It was quite painless, really. 

I may never get around to getting that sourdough dry start up.  But if I do, hopefully it will live for a long time and give me plenty of very good bread, and then I'll do a taste comparison.  I agree with you, how does it taste is the most important thing  --   and how much energy do you have to give to the process?   To me it's important to be able to easily and quickly knock off a good loaf of bread twice a week, without thinking too much about it.  Getting there and enjoying the ride so far...

proth5's picture
proth5

that you are trying to accomplish - keep a culture of commercial yeast going - or - create a sourdough starter?

I ask, because the process involved (and the yeasts involved) are quite different.  What you buy in a packet as commercial yeast has been grown on a molasses solution under sterile (not just clean) conditions. It is not adapted to living with various lacto baccili in an acidic environment.  Commercial yeast is Saccharomyces cerevisiae, whereas what usually is involved in sourdough is Candida milleri (or Saccharomyces exiguus)

So, over time, as you feed it on flour and water, it is outcompeted by the wild yeasts in the flour that are more adapted to living in the environment - while the commercial yeasts fade (or die), the wild yeasts have not yet taken hold (and you keep putting the thing in the refrigerator which doesn't help them at all) so, as you observe, the culture becomes weak.

Also, putting commercial yeast into a flour/water mixture as a way of "jump starting" a sourdough culture is - well - like planting radishes to jump start the production of tomatoes. (OK, maybe that's a bit of a stretch ...)Yes, the radishes will sprout up quickly and give you green shoots - just as commercial yeast will quickly produce a yeast filled, bubbly substance - but if you want tomatoes, you will have to pull up the radishes and take the time to plant the tomato seeds (or the wild yeasts contained in the flour) - they may take longer to sprout, but will give you what you want. 

Maintaining a true sourdough culture, is a bit different, as it has already been populated with wild yeasts and once the wild yeasts and lacto bacilli come into balance, they are very stable- even in a non sterile environment.

Perhaps you will want to peruse this site http://www.dakotayeast.com/yeast_production.html which gives a good overview of how commercial yeast is really propagated.  Frankly, I consider that whole process is best left to the professionals (or folks who do brewing...)

You have been given excellent instructions on how to maintain a sourdough culture by the posters above (although some talk about a poolish - which is a one time thing rather than an ongoing culture - the "maintenance" of a poolish is non exisitent - you mix a poolish - it matures - you use it to bake and it is gone) - none really discusses what it would take to maintain an ongoing culture of what we know as commercial yeast.  They really are two different things and failure with the commercial yeast culture does not naturally lead to failure with a wild yeast culture.

BTW; Instant dry yeast and "regular"dry yeast are the same strain of yeast - the difference between the two is in the drying process which for "regular" dry yeast results in a higher proportion on dead yeast cells and a larger granule size that usually responds better to dissolving in water prior to use.

Hope this helps.

brendateese's picture
brendateese

--  I am trying to keep a culture of commercial yeast going.  I did read a post from a person here at TFL who has a commercial yeast starter still going strong after 9 years I think he said.  Or was it 12 years?  Anyway a long time.

thanks for the encouragement to try out the sourdough start.  I thought the sourdough might be more fragile than commercial yeast, that's why I wanted to have success with commercial yeast before I ventured into a wild yeast start.  But it seems that I had that backwards, the wild yeast is actually more compatible with the acidic ferment...  who knew?

:>) 

wayne on FLUKE's picture
wayne on FLUKE

That way if you kill it you have another chance!

It really is easy. I got my Carl's starter a couple of years ago and had no experience with sourdough. It is still alive and well.

Since I only use it every couple of weeks. I keep my starter in the fridge and get the best results by building it up by feeding 3 times starting  a day or 2 before I plan to use it. After the first feeding I divide it, feed both parts, but one back in the fridge and leave the other out to be fed again (and increase the volume) before using it to bake. A nice easy sourdough to start with is Teresa's Basic White Sourdough using 100% Hydration Starter

wayne

brendateese's picture
brendateese

That's it! 

As we speak the envelope of Carl's sourdough dry start is on the counter all ready to go this morning.  The instructions call for only a teaspoon to get the starter up.  That leaves plenty in reserve in case the starter fails.  Which now that I have all this wonderful advice on how to keep the starter going I don't think that will happen.

This has been a great thread for me, many thanks to everyone who contributed to my enlightenment. 

Seasons Greetings, folks.  Only two days till the winter solstice, and then the light will begin to return.  We're going through the dark rump end of the year right now but we're nearly through it.  In only a couple of days we can start to think about Spring without driving ourselves crazy.