Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne Bread and Mold Topics
Name: David
Status: other
Grade: other
Location: NY
Country: N/A
Date: 12/6/2005


Question:
I'm a retired teacher, age 71. I make bread every week for my own enjoyment. I keep it at room temperature in a (new) plastic bag. About 6 days after making it, it gets moldy.

Q-1 What can I do to extend the pre-moldy period a few days? I have observed that commercialy prepared breads stay mold-free for considerably longer periods of time.

Q-2 Is it OK to eat bread molds? My son is color blind and often can't see the color difference between the mold and the bread's crust.


Replies:
Commercially prepared breads usually have preservatives to prevent mold from growing on them. A very common mold inhibitor is calcium propionate, which is toxic to molds. It is also toxic to humans at high concentrations, although it is probably harmless at the concentrations found in bread. Since one of the benefits of making your own bread is that you get to eat bread that is free of preservatives, I think adding a preservative might be self-defeating.

Eating bread mold is not a good idea. While many kinds of mold are perfectly harmless, there are some extremely nasty molds out there that can make you very ill. Some of them are even quite common. I recall a mycology professor of mine used to say that mold on bread isn't worth the risk, but that mold on cheese is fairly safe.

C. Perkins


First off, bread that is moldy in any way should not be eaten and be discarded immediatley. A few suggestions: After baking, the bread should be cooled and stored in a breathable container for the first day. If you wish to keep it for more than a few days, it should be refridgerated in a sealed container only after cooled and dry on the oustside. If you wish, you can also freeze the bread in a freezer bag. Do not reuse cheap plastic bags to freeze the bread since they are typically polyethylene and are actually NOT air tight...they breath and what will happen is the bread will get "freezer burnt" which means the self defrosting freezer will dry out the bread.. I would suggest that bread stored in the fridge should be discarded after 5 days. Stored in the freezer it will last a few months easily. By the way, our sense that is most sensitive to detecting mold is not the sense of sight but of smell.

pf


A good way to extend your breads life is to keep it in a dark,dry, cool area. Mold needs moisture and heat to grow, and many molds need light to grow. Keeping the bread in something airtight will also help (like a zip-lock bag). Just make sure to squeeze as much air as possible out of the bag before closing it. Most molds will not do any harm if they are not ingested in large quantities. The blue in blue cheese is actually mold!

Grace Fields


The carbohydrate etc. in the bread dough is food for bacteria and mold just as it is for you. I would store the dough in the fridge until you are ready to bake it. You can take it out of the fridge for a period before you bake it if you like, but as long as it is at room temp. the bacteria and mold that are in the air (and inside a bag you store it in!) are going to start having a feast. Refrigeration slows them down.

Van Hoeck


Q-1 Commercially prepared breads contain specific chemical preservatives that inhibit the growth of many microorganisms (molds, bacteria, fungi). I would hesitate to offer a particular chemical additive because there are many and it would not clear how it would affect the other properties of the bread. The ingredients in bread -- flour, yeast, milk, eggs, and so on are great feeding grounds for all sorts of microbes -- some harmless, some not so harmless. Add to that warmth and water and you have the makings of a good garden for a lot of "bugs". Two general approaches would be to limit the amount of oxygen available by storing the dough tightly in plastic bags (which you already do apparently), and refrigeration/freezing which inhibits the growth of most microbes. The websites below may provide you with some additional insights into preservation of the dough. But storing uncooked dough for days is inviting the risk of possible food poisoning -- bake it, then store it.

http://www.math.unl.edu/~jump/Center1/Labs/Control%20of%20Molds%20in%20Breads.pdf

http://www.breadmachinedigest.com/library/dough_enhancers.html

http://www.britannica.com/bcom/eb/article/4/0,5716,120864+4+111136,00.html

http://www.seps.org/oracle/oracle.archive/Living_Things.K-5/2001.01/000978561940.16730.html

Q-2 Unless you or your son is a microbiologist, I would not recommend eating bread mold, or even raw dough for that matter. There are just too many possible harmful microbes that can grow in/on bread.

Vince Calder


Some possibly helpful sites:

http://www.fi.edu/tfi/units/life/forums/living/bread.html

http://www.newton.dep.anl.gov/askasci/gen01/gen01509.htm

http://www.sirinet.net/~jgjohnso/fungi.html

J. Elliott



Click here to return to the General Topics Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (help@newton.dep.anl.gov), or at Argonne's Educational Programs

NEWTON AND ASK A SCIENTIST
Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Weclome To Newton

Argonne National Laboratory