wild things

December 29, 2012 9:38 AM

I would like to serve my guests bread prepared with fermented wild yeast (wild wheat yeast+spring water, fermented). Are there any safety concerns I should be aware of? My guests include older people, people taking medicines, children and nursing mothers.
posted by leigh1 to food & drink (12 answers total)

I bake once a week with an ongoing wild yeast culture--no one has gotten ill in over 10 years. There's nothing to fear. Yeast in packets is the same stuff, more or less.
posted by Ideefixe at 9:41 AM on December 29, 2012

This is pretty much just sourdough. The yeasts and bacteria in question are not harmful and, in any case, they are all killed when the bread is baked.
posted by ssg at 10:14 AM on December 29, 2012 [2 favorites]

I've made my own sourdough starter from wild yeast. As long as you're past the point where it smells like socks soaked in cheesy beer, and made it to the point where it smells like sourdough bread, you should be good to go.
posted by themissy at 11:25 AM on December 29, 2012 [1 favorite]

Yeast in packets is very different from sourdough. Apart from that, I agree with everyone. I've been baking for almost a year now. Note that sourdough bread has different tastes depending not only on the ingredients you use (whole wheat becomes more sour than white flour) but also on the ambient temperature (a deeper, more yeasty flavor at 66F vs a more sour flavor at 78F) and even the hydration of the starter/dough (more water = more sour). I have heard of people getting sick from sourdough (Google site:ask.metafilter.com sourdough) but I'm sure it's very rare. If you know anyone who is sensitive to MSG/autolyzed yeast, saurkraut, yogurt, cheese, etc. then make sure they know what they're eating.
posted by gray17 at 12:15 PM on December 29, 2012

It's certainly possible for sourdough to have bad things in it, but it's pretty obvious from the weird color or smell. Under normal circumstances the acidity will prevent nasty organisms from taking hold.
posted by O9scar at 12:34 PM on December 29, 2012

Anecdotes of safety for pregnant women, children and the elderly should not be enough to reassure you. Please wait till an authority comes in or you see some research/government/medical site/cite.
posted by taff at 1:37 PM on December 29, 2012

You will know if the yeast has been overpowered by not so great, bacteria. Firstly, your bread will not rise, so easy to know there.

Secondly, it will be baaaaad. Like, rotten eggs bad (don't be put off by a layer of thin, grey fluid on top. This is just "hooch", ie alcohol produced by the yeast). It will not be anything you will want to cook with.

If you are further concerned, you may add a dollop of natural yoghurt to your sourdough, or pineapple juice. Both help lower the PH (making it harder for other bacteria to grow), and create an environment conducive to yeast (yoghurt actually has the acidopholous bacteria that lives in a symbiotic relationship with yeast in a healthy sourdough).

Sourdoughs are nothing to be afraid of, for anyone. I have been baking sourdough breads for years - I have read phds on the bacterial lives of sourdough (and it bored even me!). I know a lot about it. There is no real health risk here.

PS I assume your sourdough is already good to go? It will take a couple of weeks to get up to full strength I find, and this will especially be the case if it's cold where you are now.

PPS Expect your rises to take much longer, sometimes even longer than stated in sourdough recipes. Every sourdough, and the conditions it performs in, is different. My sourdoughs take much longer to rise than stated in any recipe. I have to go off sight and feel. If this slow rise concerns you, consider an overnight bulk rise (in the fridge), or adding a teaspoon of instant yeast at the bulk mixing stage, once you've already incorporated your levain.

Enjoy your bread. It's a wonderful hobby.
posted by smoke at 2:14 PM on December 29, 2012 [1 favorite]

PS Cites:

Colorado State University Extension - SafeFood Rapid Response Network:

"After discussing the safety of a product such as this with two fermentation experts at Cornell University and two experts at Oregon State and Washington State, Donna L. Scott, Senior Extension Associate in the Department of Food Science at Cornell University, has concluded that there is little risk of contracting foodborne illness from properly prepared and handled starters, whether or not they contain milk.

Properly prepared starters are safe because they become acidic due to the fermentation action of lactic acid-forming bacteria present in the mixture. These bacteria and the acid environment formed inhibit the growth of other bacteria, but do allow yeast, if added, to grow and help leaven bread products."

King Arthur Flour:

Sourdough starters are hearty, and easily resist spoilage due to their acidic nature. The pH of a sourdough starter discourages the proliferation of harmful microorganisms.

However, if your starter turns ominously pink or red; shows signs of mold growth, or smells decidedly putrid, throw it away and begin again. Luckily, in our experience, this rarely happens.

I, too, would agree that this rarely happens.
posted by smoke at 2:20 PM on December 29, 2012

Once the bread is cooked everything inside is dead. Just cook it through.
posted by Evstar at 2:21 PM on December 29, 2012

You know, people who live in industrialized nations get really freaked out these days about food they prepare themselves from super-scratch. Like, could the tomatoes I grew in my yard have too much lead in them from the soil? Could the eggs from the chicken coop I just started up have salmonella? Will these bean sprouts I started be contaminated with bacteria?

And yet . . . we don't spend a lot of time asking these same questions about food we buy at the store, that has been grown, prepared, and stored in various unknown locations under varying degrees of safety, and handled by possibly hundreds of people before we ever even see it. We buy this food and eat it on faith, even though every year 76 million people in the United States do get sick from food poisoning -- mostly from food they originally bought at a restaurant or store.

I assume you will be baking this bread in a clean kitchen at a very high temperature for a standard period of time. Very few bacteria can survive that sort of treatment. If the bread doesn't look, smell or taste bad it will probably be just fine. If you're worried, make sure to mention to your guests that this is bread you made with your own starter; that way, your guests get to choose whether or not to have some.

Personally, after years of trying to get closer to the origins of my food by growing and preparing more of it myself, I've stopped having nearly as much fear as I used to about how I might screw up my food, and started worrying a lot more about how people I never see might screw up the food I get already prepared.
posted by BlueJae at 5:22 PM on December 29, 2012 [5 favorites]

The end product is more delicious than "ordinary" bread, but not different in any food-sensitivity way. If a person can eat yeast-risen bread made with flour, period (i.e. no sensitivities to yeast or fermented things or gluten) then they can eat your bread just fine.
posted by desuetude at 11:10 PM on December 30, 2012

Thank you all so much.
posted by leigh1 at 3:45 PM on January 5