Hi,
I make a Jewish rye bread that calls for leaving buttermilk out (unrefrigerated) overnight uncovered, then mixing it with rye flour and leaving it out another 24 hours, but covered. I forgot to cover it. Should I be concerned? I'm not sure what the impact would be from covering or not covering it.
The resulting bread is tangier than usual, but my kitchen is also warm this time of year. I haven't experience any symptoms that would me think I'm sick, though my mouth has a sour taste. But it's morning, so I don't know if that is because of the bread.
Thanks in advance for your help.
Up to you. If it's bad - don't use it. Enjoy!
I don't know if it is bad. That's what I'm trying to figure out.
Taste it - you'll know. Enjoy!
It's not that simple, unfortunately. It's always a tangy loaf, just more so than usual. That doesn't necessarily mean it's bad or unsafe.
Food safety should not be a problem because the buttermilk is acidic. Online, I see pH values for buttermilk are claimed to run from 4.4 - 4.8. The US FDA considers that 4.6 is safe, but that's to leave some margin for error and anything lower than 4.8 suppresses most common disease microbes.
Mixing the aged buttermilk with the rye flour will raise the pH, most likely into the range of 5 or there abouts but it must be staying low or the rye would probably disintegrate over those 24 hours. I am assuming that the buttermilk had live cultures, so that there were some lactic acid bacteria; they would continue to lower the pH during the 24 hours.
Leaving the dough uncovered shouldn't have been a problem because 1) the dough being acidified would suppress unwanted microbes, which in any event would have trouble competing with the LAB, and 2) the surface would have dried out somewhat which would slow down microbe metabolism and make it hard for them to penetrate furrther into the dough.
As long as the buttermilk had live LABs, then, there should be no cause for concern.
TomP
Thanks for your response. My buttermilk was standard grocery store buttermilk, so I don't know if it has live LABs. It is "lowfat cultured buttermilk."
It should contain live LABs (referring to typical US buttermilks; I don't know about other countries). The older it gets, the fewer live bacteria survive, so it's probably better to use the buttermilk before it gets too far beyond its sell-by date.
I wouldn't be concerned, but baking will kill most microbes anyway.
I don't think the presence of microbes per se, even if alive, would be a problem. One wants to avoid a buildup of toxic byproducts like botulin or shiga (from e coli) before the microbes are killed. A low pH does the trick.