Bread baking at home is increasing in popularity, particularly with the proliferation of recipes that make it easier by calling for extended periods of rising in which the Dough does not need to be kneaded.
Not-So Friendly Bread?
One popular home-baked bread recipe is commonly known as Friendship Bread or Amish Friendship Bread. There are some variations, but typically the recipe starts with a concoction of flour, yeast, water, sugar and milk that is allowed to sit on the counter for 10 days, during which it is occasionally stirred (this particular recipe admonishes against using metal utensils), then more flour, sugar and milk are added and the recipe is divided among friends, who are supposed to do the same thing, passing it along like a yeasty chain letter.
My mom gave me some of this once. I threw it away. I don’t think she ever used hers, either.
A report from the University of Wisconsin Extension Service lays out the logic behind the recipe and the potential problems with slow-rise doughs:
While this starter contains yeast, the primary reason to hold the mixture at room temperature is to allow Bacteria naturally present in the ingredients to produce acids which lend a tangy flavor to the final bread and promote leavening of the loaf. 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. Extended-rise no-knead loaves lack the protection of the lactic acid formed by a fermenting starter. In extended-rise dough, the prolonged holding is designed to facilitate the formation of the dough matrix by allowing gluten proteins to fully hydrate and align in the watery dough.
It’s easy to get freaked out about the prospect of eating something with milk in it that’s been sitting out for days or longer. While milk is pasteurized to eliminate pathogens, a report from the Centers for Disease Control notes “improper pasteurization and incidents of contamination after pasteurization occur,” and found that dairy products accounted for 14 percent of all food-borne infections causing illnesses, second only to leafy greens. Ten percent of all deaths were linked to consumption of tainted dairy products.
The report says these numbers are likely high because of the extreme number of cases reported to be related to consumption of raw milk; other cases were related to a norovirus outbreak caused by improper food handling after pasteurization.
There are no reports out there of people getting sick from eating Friendship Bread, but it still seems pretty sketchy to me.
What Could Grow In Bread Dough?
The warm, moist environment that is great for yeast is perfect for bacterial growth as well. Researchers at Virginia State University found significant growth of Salmonella enterica and Staphylococcus aureus in bread dough made with flour, water, salt and yeast left on the counter for 24 hours, as many no-knead recipes call for.
Salmonella is one of the most common food-borne pathogens, and can cause gastroenteritis (what we commonly think of as food poisoning) or bacteremia in immune-suppressed populations.
Staphylococcus is a common bacteria found on the skin and hair of infected individuals, who can then pass the bacteria on to others if they prepare food that is not handled properly. A staph infection can cause nausea, vomiting, diarrhea, loss of appetite, severe abdominal cramps and mild fever, and usually resolves in a couple of days.
Researchers found significant increases in pathogens after six hours of fermentation at temperatures ranging from 21 to 38 degrees Celsius (that’s about 70 to 100 in Fahrenheit, covering the spread of most homes).
Food Safety and Bread Baking
If you still want to make no-knead or Friendship Bread recipes, here’s how to do it a little more safely:
Keep your work area and your hands clean by washing frequently with hot, soapy water.
Never taste dough before it has been cooked.
Consider an alternative recipe. UW Extension says a recipe using yogurt or buttermilk instead of regular milk is a better choice because it puts acid-producing bacteria in the starter from the beginning, as well as helping to inhibit pathogens that might spoil the mixture.
Give it a sniff. Starters should smell pleasantly sour and look bubbly. Discard starter that smells off, is moldy or has changed to a reddish or orange color — and don’t taste it!
Choose recipes that rise in the refrigerator instead of on the counter to prevent growth of bacteria.
Cook your dough thoroughly. Common wisdom has it that bread is done when an instant-read thermometer inserted in the center (go in from the bottom so the hole isn’t visible) reads 190 F, but for dough with eggs or milk, shoot for 200.