Science Buddies: "Ask an Expert"

My daughter conducted an experiment to test how the location affects the rate at which bread mold grows. Nothing happened to the bread. We had four locations next to window with sunlight, in the cupboard with no light, in the cold/fridge and at room temperature on top of the kitchen counter. We placed three slices of bread trials in zip local bags in each location, added 10 drops of water to each, exposed the slices to the air for an hour to get the mold spores to settle on the bread, put them in the bags and sealed them. It's now been more than 20 days and the bread simply went stale and dry at each location. Some more than others. Because of time restraints how can we stick with the experiment without having any measurable data? Her teacher asked her to look into the ingredients in the bread for the presence of preservatives. How can we recover from a experiment that did not work?

Bread bought from the stores has preservatives and hence will not grow any mold on it for a long time. For her age level it is a good project to see how effective the preservative s works. She can always state that preservatives are effective and prevent bread from molding. You can make a bread dough at home and see how long it takes to mold. Put it in a moist place. If you are due for the project the result would be inconclusive and you can state that the preservatives in the bread prevented bread from collecting mold.

Hello Erivas,

Congratulations on conducting experiments with your daughter!
I am sorry you did not the results you expected with the bread. However, what you got are still results. As the other expert suggested, it is still an indication on how effective preservatives are. He also suggested another experiment that could be achieved in between now and the due date of the project. I would add another suggestion: I noticed that organic bread tends to mold much faster than "regular" bread. Maybe you could try again with organic bread.

Good luck and don't hesitate to ask again if you have more questions

Heloise

Hi Erivas,

Jmehta14 has given you very good advice. The preservatives in bread to slow down the growth of mold, but 20 days is a really long time. I notice that your project is due on April 30, so you have just time to set the experiment up again using bread without preservatives. Be sure to add a few drops of water to each piece of bread to ensure sufficient moisture for the mold spores to germinate. If the temperature is at least 21-22 degrees Centigrade, you should begin to see mold colonies by the end of this week.

If you don't have time to repeat the experiment, then you will have to write up the results as they are (no results) and provide an explanation. However, if possible, it would be better to do it again.

How are you planning to measure the results?


Donna Hardy

My daughter was planning on measuring the results in cm squared. The bread measured 10x10 so, we were going to measure it as an average of all three samples as a percentage of cm squared. Due to time if she were to set up the experiment again she would have to re-do all the work she has already turned in. Change her question and hypothesis. We are now at the stage where she is putting her board together. I will leave it up to her if she wants to start over.

If she decides not to start over I will make sure she still has a data graph showing no activity on the bread mold and have her explain in her conclusion the results of the experiment.


Thank you all for your help and support,
The Rivas Family

Hi,

Your daughter's plan to measure in square centimeters and do the experiment in triplicate was a good one. I understand that your daughter has done a lot of work already, and it's probably better to concentrate and write up the projects with the results are they are. It is a complete project, and no results are perfectly acceptable, as long as she can explain what may have happened. She should include ideas for changing the experiment, if she were to do it again, in the discussion section.

Donna Hardy

Thank you to all the experts...your help is greatly appreciated. We will let you know how.the project turns out.