The Fresh Loaf

News & Information for Amateur Bakers and Artisan Bread Enthusiasts

Vomiting & diarhea: how can you tell if wild yeat is the only living thing in your starter?

sallam's picture

Vomiting & diarhea: how can you tell if wild yeat is the only living thing in your starter?


I've been making sourdough bread and pizza several times during the last 2 weeks to my 8y and 11y old kids. The 8y complained from diarhea several times, then recently started vomiting repeatedly till he started to faint. I had to take him to hospital. He still suffer from diarhea, and his brother (11y) started suffering from stomach pain and diarhea too.

I make my bread and pizzas from a sourdough starter that I made myself at home. Could that starter be the reason for this? I'm thinking, maybe, during the first stages of catching the wild yeast, some bad bacteria could have infected the culture and developed in the starter too?

Is wild yeast too strong or bad for kids, specially when it has that strong sour taste?

Personally, when I eat too much from my sourdough bakes, I kind of feel like vomiting, as a result of that sour taste left in my throat, specially in the morning after a late dinners.

Should I avoid baking with my sourdough starter? How can you tell if wild yeat is the only living thing in your starter?


LindyD's picture

This is not something that can or should be diagnosed over the Internet, given your children are ill.

Take a sample of your sourdough culture to the doctor handling the care of your kids and have him/her examine it.

I hope everyone feels better and fast.

Maverick's picture

How old is your starter? What does it smell like? How did you start it?

An established sourdough starter will normally be to acidic for bad bacteria. But a new one can have issues. Normally this results in an off scent.

bassopotamus's picture

I would think that if you cook through, most everything bad should die off (not much survives past 160 and bread isn't done until 200), but like the others said, talk to a doctor.

rainwater's picture

Bake off some regular instant yeasted bread to see if everyone has the same reaction.  Bake off some sourdough bread in a couple of weeks, and see if everyone has the same reaction.  Sourdough bread is supposed to be "more digestible", not less. 

I feed my sourdough starter once a week because I bake on the weekend.  I feed the starter about 1 or 2 days before the weekend, let it double/triple, punch it down, and refrigerate until I'm ready to use. 

It could be several different reasons.  Maybe a lab could test your starter?  Generally speaking, I don't think most doctors know that much about food borne illness, or the viability of the food we eat.  If you feel nauseaus after eating your sourdough bread, then the conclusion would be that something is amiss with your sourdough.  I never have a "sour" taste in my mouth from eating my sourdough bread. 

None here are experts, but if my sourdough bread left a 'sour' taste in my mouth, and made me nauseaus, I wouldn't eat it........I bake about 1/2 my breads with instant yeast....I enjoy them just as much......

dmsnyder's picture

Hi, sallam.

I'm sorry your kids are ill.

Sourdough's acid environment is generally inhospitable to bugs that cause diarrhea and vomiting. It is much more likely your children brought home a "stomach flu" virus from school. Sourdough cultures have been in use for thousands of years without refrigeration, and food poisoning from sourdough bread must be rare to non-existant.

However, if you have yourself felt ill after eating your sourdough bread, and this has been repeatedly, you have to suspect something contaminated your culture. (If you have enriched your sourdough bread with eggs or milk products, they are much, much, much more likely sources of contamination that would cause your children's symptoms.)

The point about Staph. toxins is true, except I'm not sure Staph will grow in a low pH medium. And I just don't know offhand at what temperature the pre-formed Staph toxins break down.

In any case, if there is any suspicion at all about the safety of your sourdough culture, I would dispose of it and start over with a new culture.

I hope your kids bounce back quickly!


uppity's picture

Sallam, and all:

From experience with a nursing child, I have to say that it can be the sourdough, though I don't know why.  25 years ago I had a sourdough culture that I used weekly, making a plain loaf of white sandwich bread that never varied.  The culture had been grown from a purchased starter.

After I gave birth to my first child it was a few weeeks before I resumed bread-making.  When I did, my son, who was exclusively breast-fed at the time, developed loose stools, though he had no apparent gastric distress.  (He screamed all the time at that age anyway, how could I tell if his stomach hurt?)

Through trial and error, I did find out that somehow the sourdough was upsetting his system.  I didn't quite believe it, nor did I want to believe it, but I stopped and started eating the sourdough often enough to be sure.  With some reluctance I stopped baking and eating it. 

Whatever was the problem was passing into breast milk.  It was not making me ill, but it was a problem for him as an infant.

I did NOT experiment with other sourdoughs or other cultures.

My son certainly has no problem with sourdough bread now, as an adult.  But it seems that sensitivity is possible, perhaps particularly with children.

Good luck, I hope you all feel better very soon!

gaaarp's picture

If you even remotely suspect that your sourdough culture is making your family sick, THROW IT OUT!!!!  Start a new culture, using only flour and water and very clean hands, utensils, and containers.  From an academic standpoint, it might be nice to know what's really in your culture, but practically speaking, in the time it would take to have it tested, you could have a new, uncontaminated starter ready to go (and at a much lower cost).

Just my two cents.


althetrainer's picture

I agree.  I would throw it out regardless.  I would also re-introduce sourdough to your kids very slowly and carefully, just in case.  I have children at home and I know how it's like to have them all sick at once.  Hope the kiddos will feel better soon.

gavinc's picture

Don't overlook that the culprit may be the pizza toppings, particularly if you used cured sausage products etc.  Also check out gluten intolerance, however you would probably already know if your kids had this.  It's unusual to read anything that indicates that sourdough is a bad thing, I mostly read where it's much healthier.  Like everyone else here, I strongly suggest getting a doctor to check things out.


bassopotamus's picture

I'd also consider cross contamination. I could imagine eating raw starter might be less than ideal, and if your finished product comes in contact with something with bacteria, it could be an issue. I don't think SD starter is that virulent, but it can be an issue with meats and poultry

jacobsbrook's picture

The  health professionals are who you should make aware of the starter question.   It is concerning that you feel ill after eating it at times also. Let them know about the starter and see what they think.  If no testing is necessary - throw it away!  Start over again just to be safe.  Always safety first.  Hope everyone feels better soon.

LindyD's picture

 The 8y complained from diarhea several times, then recently started vomiting repeatedly till he started to faint. I had to take him to hospital. He still suffer from diarhea, and his brother (11y) started suffering from stomach pain and diarhea too.

Since one child was already examined in the ER, there was probably a diagnosis given.  I'd follow the advice given by the doctors, or get a recheck.  Kids (and some adults) are notorious for not washing their hands.

dmsnyder's picture

There is an aphorism in medicine - "When you hear hoofbeats, don't think of zebras." That is just a way of saying "common things are common."

As I said before, the most likely diagnosis is viral gastroenteritis, not food allergies or food poisoning. It may be worth a call to your children's school nurse about about why kids are missing school this week and for what complaints children's are being sent to the nurse's office. Your local health department's epidemiologist or Public Health Nursing staff would probably also have that information.

If the nurse tells you that lots of kids in the school have the same symptoms as yours, unless there is an outbreak of sourdough baking in your community, that should be reassuring and lower your anxiety about your starter.

Again, if you have any suspicion left, it's not that big a deal to start fresh with the starter.


sallam's picture

Thank you all so much for your kindness and valuable advises. I've decided to stop baking with sourdough altogether. Thank God, the kids are fine now, and the symptoms are gone. I've returned to using instant dry yeast as of tonight, and personally I feel much better. The uncomfortable after sour taste is gone too (it was more obvious in bread than in pizzas). I don't think I'll make a new starter anytime soon (I started mine using wheat flour and orange juice). My starter was always kept inside the fridge, never left outside (even after feedings). I guess maybe making and keeping starters are not suitable for all places. Maybe the air in my neighborhood has more bad bacteria than the good ones.

jj1109's picture

keeping it in the fridge all the time may have been part of the problem - allowing your starter to grow at room temperature after feeding will allow the "good yeasts" to flourish, out-competing everything else. It may be simply that keeping it cool allowed some bad bacterial growth whilst the wild yeasts were kept dormant.

Good to hear that everyone is OK now though!

Maverick's picture

You may want to get the family tested for allergies. Those with mold allergies may be sensitive to sourdough. It is always nice to know what allergies in general children may have.