Thursday, April 19, 2012

An Award Winning Science Project

Kira and her proud parents
What kind of milk works best when making cheese...

Kira Pelletier is a 6th grader at the Avon Grove Charter School in West Grove, Pennsylvania.  A few months ago she was having a hard time thinking of a project for her upcoming school science fair.

Then, she and her mother were looking in our book, Home Cheese Making, and, Kira says:

We were wondering how the pasteurization process affected different milks because the Cheese Queen said never to use UHT (ultra high temperature) milk in the Mozzarella recipe, and bam! My science fair project was born.

Kira's project, called "Pasteurization and Cheese," won first place at her school fair, and then second place in the Chester County Science Fair. After that, she advanced to the Delaware Valley Science Fair a few weeks ago.  This fair is the last one in the sequence for her school and grade.

At the Delaware fair, Kira won a special award - the Future Scientist Award from the Eastern Regional Research Center of the US Department of Agriculture for having a meritorious project related to agricultural research. She has been invited to a lunch and exhibit on May 8th.



After Kira's win at her second fair, her mother, Janet Hesselberth, wrote to us with the good news and described the project as follows:

Her project was inspired by your statement that milk pasteurized at high temperature (boxed milk) was not suitable for cheese making. 

She made cheeses from raw, powdered, evaporated, UHT (ultra high temperature) and HTST (high temperature/short time) milks, using the 30-minute Mozzarella recipe each time. She measured time to set, quality of the curd, elasticity, density, and yield. 

Of course the raw milk was best, and we could see a pretty clear trend that the higher temperature the milk had been exposed to, the poorer cheese (or bigger mess) that it made.

Kira added:

It was easy to tell. Some, like the HTST milk and raw milk, formed a definite mozzarella curd. The others just made milky slush, like the UHT and evaporated. It was not hard at all to tell which ones would make good cheese and which ones would just make a mess.

Pictures of Kira's Project:

Citric acid, rennet and the different kinds of milk Kira tested
Healthy curds
Weighing the cheese





At the end of every project, there is a summary of it called an abstract.  Here was Kira's:

This project was designed to determine the effects of differently processed milks on the physical attributes of an enzymatic cheese, and through that, the effect of processing on milk.

This was accomplished by timing how long the cheese took to curd, using the method of displacement to determine the density, feeling the cheese, and weighing the cheese.

As a result of these tests, it was discovered that the more processed milks may have destroyed the proteins needed to create cheese, while less processed milks created high-quality cheese. Therefore, it was concluded that higher processing has a negative effect on the milks exposed to it.

The contributions of this project to the scientific community are twofold. First, it was demonstrated in the experiment that enzymes play an important role in cheese making, contrary to popular belief. Second, it was also demonstrated that higher processed milks have a negative effect on mozzarella cheese and may not be the healthiest milk for human consumption.

Congratulations, Kira! 

You have made a point that can't be overstated- over processing milk (and any other food) destroys important ingredients.  Just like cheese, we need the enzymes and the bacteria found in whole foods to be healthy.

4 comments:

TJ said...

Fantastic Science Project, Kira! Thanks so much for sharing!

Simona said...

This is just great! Bravissima Kira and thanks for sharing your efforts. The awards are well deserved.

hendrik said...

thank you kira this project of yours teach me a lot of things i didnt know ,keep on doping things like this and i know yuo will have a very bright future very proud of you

Mary said...

Wow! Kira! Lots of very good information and the support pictures were extremely helpful to define the issues inherent with these differently processed milk types. Excellent work!