The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Contamination with baker's yeast?

amolitor's picture
amolitor

Contamination with baker's yeast?

I've been monkeying around with firm starters, and haven't had a lot of success using a firm starter from start to loaf (I never get enough leavening power). The other day I figured I'd convert some of my sticky "levain" into a more liquid starter. Made up a batter, which started bubbling almost immediately. I'm pretty certain my levains had wild yeast, just not a LOT of it. Anyways, after a couple feedings my liquid buddy is growing nicely. However, this morning I fed it, and within 2 hours it had doubled, within 3 it had nearly tripled. This seems like a pretty short lag time, but I'm very new to wild yeasts.


So, a question in two parts: Can a new starter get contaminated with baker's yeast? (I bake a lot, I assume there's baker's yeast pretty much all over the place) How would I know if it had?


 

amolitor's picture
amolitor

My kitchen is quite warm, around 82F, so I would expect things to be fairly active. The question is 'is this TOO active to be wild yeast?'


 

Mini Oven's picture
Mini Oven

about it not having enough leavening power.  The acid levels in a mature starter is often too unpleasant for instant baker's yeast and so the wild yeasts choke out the tame ones. 


Now about the firm starter being week, I think not.  One does have to think in terms of inoculations, ideal conditions and yeast cycles.  The higher the hydration of the yeast and flour mixture, the faster the beasties will feed and burp and raise the dough.  The higher the inoculation, the faster the beasties.  The higher the room temp, the faster the beasts.   This all adds up to fast leavening power. 


Now if it is the sourdough flavor you want, you may find it better to slow all of this healthy feeding and burping down just a little bit.  You might want to look for a cooler place to store your starter where you won't forget it.  (Or you might want to add just a pinch of salt to the starter when feeding while the weather is warm.)  Otherwise it might decide to eat you out of kitchen and pantry.


So what now...  to get from firm starter to a loaf?  You need to get yourself a recipe and follow it.  If it askes for 100% hydration, for every 100g starter (50g water and 50g flour) use about 10g to 20g firm starter.   Let it rise (4-8 hours or so)  and just as it reaches the peak of the rise, use it in your recipe. 


You can use cold water or add salt to slow down the fermenting, use 1.8 or  2% of the flour weight to figure the amount to add and subtract it from the recipe salt so the whole loaf doesn't get too salty.  (I find it easier just to measure out the salt for the recipe and take a portion of that to salt the starter.)


So get that recipe and go for it!


Mini

amolitor's picture
amolitor

Actually, I did just that. I've wrestled with Joe Ortiz' Pain de Campagne recipe for a long time, with limited success. I think I'm just bad at reading a firm starter -- they don't communicate nearly as well as 100% hydration one. I don't know if I'm taking the levains too ripe, or too young, or both! But, I've never been able to get a loaf that wasn't moderately brick-like.


There's nothing even close to 100% hydration in the recipe I'm talking about -- everything's around 60-65, at every stage of the recipe, and that's exactly my problem.


Anyways, that's a different post (one I already made!)


 

Mini Oven's picture
Mini Oven

So you haven't got the problem solved yet?   I thought I had commented on your first thread but I see it got lost or I got distracted.  Sorry about that.  Lets get your starter fixed first.  Then on to the recipes...


I suggest you read what Debra Wink wrote on that kind of problem.  Regular feeding brings it out in about two weeks.  Her writing on thiol compounds might be interesting to you.  Subject thiol and discussion starts at this Link: http://www.thefreshloaf.com/node/18144/sourdough-loosing-elasticity-please-help#comment-121566


That is a pretty long discussion on many activities in starters and may take some re-reading in parts.  Thick with information.  Don't forget to have it added to your favorites so you can get back to it.


Mini

amolitor's picture
amolitor

I think I licked the sticky levain. I got a reasonable dough a couple times, that did not disintegrate during proofing. There just wasn't a big enough yeast population in the final dough build, so it only rose slightly. I'm better at reading a firm levain starter, just not good enough.


There's also indications in the Usenet archives that Joe's recipe just doesn't create anything with much oomph. I've actually found no evidence that anyone has succeeded with that recipe.


I've also not run across (though I haven't looked) any other recipes that are based on 65%-ish starter/levains from start to finish. Most everyone goes liquid, at least part of the time.


In other news, the first loaf baked off from whatever the heck I have growing at 100% hydration went without a hitch. Not perfect, but it's ok for a first effort.


Back to the original question: It sounds like the sort of growths I am seeing are not out of line for wild yeasts? I confess I haven't studied the archives in detail, but I had the definite impression that doubling within 2 hours of feeding was... aggressive. If it's within the bounds of normal then, great! I'm pretty darn sure I started out with wild yeast.


 

Mini Oven's picture
Mini Oven

Yes, doubling in 2 hours is fast.  I must agree.  I understand more after just reading all your comments in the last 2 weeks.   This is an instant yeast with a drawn out ferment.


Sudden growth could be bacterial.  You have a valid point there...  How does it smell?


I would think with the warm temps, your times will be much shorter.  You mentioned that cooling helps.  Getting the salt in early might also help.  Putting part of the salt in can do wonders, have you tried that yet?

amolitor's picture
amolitor

Actaully it doesn't smell like much. My sense of smell is pretty attenuated, but I can say there's no strong smell, and what there is (to the limits of my senses) is mildly yeasty.


Upon further reflection, it may not have quite doubled in 2 hours. It was definitely more than doubled in 3 hours, though.


I started out with maybe 1/4 cup of 65%-ish hydration mostly-whole-wheat starter, that was spongy. Added 1/4 water and 3/8 cup flour (roughly) to that. Threw away half of the result and fed same every 10-12 hours for maybe 3 rounds. This is all pretty approximate. Anyways, I was shooting for about 1:2:2 feedings every 12 hours.


Flour was KA organic bread flour. After 36 hours or so it was definitely rocking along.


The firm starter was a couple weeks old, I'd been fooling around getting to know it, tinkering around feeding it at various intervals (2 days, 12 hours, and a few in betweens) at pretty close to Debra Wink's 5:3:5 ratio -- this is basically what Joe uses, or at least, fairly close. This was pure experimentation on my part. Anyways, I think there was a stable but not vigorous culture of yeast going on in there when I went to (approximately) 100% hydration.


 

Mini Oven's picture
Mini Oven

and it may be kicking around some instant yeasts but as the wild ones take over, they will take over.  If it is tripling, hey!... then the wild beasties are in charge!  You might want to try a bigger flour feeding to make the 12 hour feeding stretch.  Like reduce the starter to an even smaller amount, a rounded teaspoon maybe and splash in your 1/4 cup water and add the flour making it dough like. 


Mini

amolitor's picture
amolitor

An amusing data point, I think the starter just crashed because I let the kitchen get too hot baking off the first loaf ;) I just peeked in at it, and.. hm, it seems to be shrinking, and oo, that's a bitter smell.. and taste. What? Then I looked at the thermostat -- 85F -- and it's a little warmer where the starter was living.


Whatever's in there seems to die around.. 86 degrees. That's encouraging!


Oops! Gave it a quick feed just now and moved it to cooler climes. We shall see.

Mini Oven's picture
Mini Oven

right into the starter.  Slows it down.  Don't forget to reduce before feeding or it will mature even faster.

amolitor's picture
amolitor

May jar is sort of small, so I'm pretty good about reducing. The darn thing is perilously close to full when I feed!


Salt, good idea.


I'll see if I've revived the thing first, though ;)


This is all very exciting. It's like gardening with invisible plants that grow insanely fast. And you get bread, not tomatos.

Mini Oven's picture
Mini Oven

The yeast just uses up all the food and then slows down gas production.  Smart move feeding it.


It is pretty warm here too, but I manage to keep the house cool.  Thick walls.