How to make cheese: Biology lesson at St Aidan's Anglican Girls' School

"The year 11 Biology students were very excited about National Science Week. Being a part of the activities brought a buzz to the school and lifted our cheese making activity (that was filmed) to a new level. Students are already asking about it for next year!" _ Sylvia Hicks | PAR - Biology, Science. St Aidan's Anglican Girls' School

Jessica Armitage

Year 11 Biology class

St Aidan’s Anglican Girls’ School

Who would have thought that cheese making required massive amounts of hand sanitizer?

Bacteria - the right bacteria found in rennet and Penicillium candidum - makes milk into cheese.

But only if it's not contaminated by the bacteria found in our daily lives, on our hands, faces, desks - bacteria is everywhere!

We learned this in a class about ... why milk goes off.... before we stared making cheese.

Cheese making was an extremely exciting experience.

We were forced to leave the warmth of our jumpers and enter a world full of unattractive hairnets, aprons and hand sanitiser.

This provided a sterile environment that would prevent contamination.

Before beginning cheese making we had mainly been focussing in class on pathogenic bacteria that can cause disease.

It was therefore very interesting to see firsthand how some bacteria that have not been contaminated can actually have a positive impact in the food making process. I mean they turned milk into cheese!

The process of cheese making required patience and accuracy when following the procedures.

First we had to pour milk into a container and place it into a water bath until it was 38^oC.

I drove my group insane because I was paranoid the water level would get so high that it would spill into the milk.

It was also difficult to get the milk at the right temperature so we were constantly added and taking hot water from the water bath.

We then added a liquid started and a sprinkle of Penicillium candidum. Once it had ripened, rennet was added and then stirred.

After forty minutes, it was set and the curd was cut into 2cm cubes. I was in charge of the cutting even though I was apparently terrible at it.

It was like cutting jelly, quite amazingly super.

After it had rested we all began to gently rock our baby cheeses back and forth. It was quite cute. I was really excited when I got to stir with a massive spoon and watched with fascination as the cubes swam around the container. They were then placed into their maturing containers.

I was quick to volunteer a couple of days later when it came time to turn the cheese which we did using an excessive amount of hand sanitiser.

With the blue vein cheese, I got to poke lots of holes in it to allow for mould to grow inwards. The cheese also had to be turned to make sure the mould growth was evenly spread.

Once the cheeses were ready to be wrapped they actually looked amazing.

Try to imagine a perfectly round cheese covered in what looked like beautiful white snow. Oh, my gosh, it was super. We then wrapped the cheese as tightly as possible with silver paper and they were ready to go.

Overall this cheese making experience was so much fun.

I absolutely loved all the processes and then the beautiful product at the end.

Click here to download:

Camembert_Recipe.pdf (98 KB)

(download)

Build a toy replica of the world's fastest train for $45 with CSIRO's energy expert Dr Alex Wonhas

The director of CSIRO's Energy Transformed Flagship, Dr Alex Wonhas, who's realizing a lifelong dream by building a solar power station in Newcastle, thinks games, such as the BBC's simulation Climate Challenge, are a good way to get kids thinking about science in relation to the real world.

As the president of the European Nations in this Flash game, you must tackle climate change and stay popular enough with voters to remain in office. Dr Wonhas Googled "Climate Change" and "Games" to find this Wikipedia page on other games to play. However, you have to pay to play some games such as Fate of the World.

In this interview with Big Science Now at the CSIRO Greenhouse 2011 Forum, Dr Wonhas mentioned how it helps kids pick things up if parents take an interest in science. He recently helped his son, Lawrence, with his last science assignment to build a toy that kids of the future would play with.

His daughter Charlotte demonstrates the train in operation here:

(download)

Click here to download:
MEGLEV_train.mov (838 KB)

The MAGLEV Train is suspended above the track by magnetic levitation - or magnetic repulsion if you like. Here's a set of plans he drew up especially for intrepid Big Science Now readers who might like to try to build their own toy.

It won't travel as fast as Shanghai's MAGLEV Transrapid Train which travels at 431km/hr:

Related video: BSN OUTtake - Alex Wonhas on science in the 21st Century.

Link: Science Fair Project on Magnetism

Wikipedia: Shanghai Transrapid

Big Science Now's roving reporter, Mandy Awabdy, went out to two hardware stores to see how much it would cost to make a toy MAGLEV Train. Mandy calculated it will cost between $45 and $35 to buy the materials. She also wrote out a shopping list and a step-by-step set of instructions interpreting Dr Wonhas's drawing. Have fun!

Steps to Building A MEGLev Toy Train

Objective:

To build a Maglev Train demonstrating the forces of magnets using attraction and repulsion.

Materials:

The materials required to build the Maglev Train which will cost between $35-$45 from hardware stores include:

Two Plexiglass sheets, approximately 24” by 4” each sheet – note this size may be adjusted the required size of the train.
2 pieces of wood strips for the base, approximately 3’ by ¼”.
A drill for the holes.
16 phillips head screws.
Two magnetic strips (ferrite magnets) fitted to the length of the Plexiglass sheet
Double sided tape.
Piece of wood that measures 3 ½” by 3 7/8” (for the train)
String to secure base platform together

Making the Mag-Lev Train Track:

Step 1. First, drill seven holes along the length edge, 3 inches from the height edge, and 1 inch apart from each other into one sheet of 24” by 4” Plexiglas. NOTE: The holes must be touching the length edge of the Plexiglas!

Step 2. Next, repeat step 1 on the opposite length side.

Step 3. Then, take another sheet of 24” by 4” Plexiglas and drill 8 holes 1 ½” from the length side and 1 ½” from the height side.

Step 4. Next, repeat step 3 on the other sheet of 24” by 4” Plexiglas.

Step 5. After that, take one of the two 3’ by ¼” by ¼” wooden strips and place it along the holes of one of the two Plexiglas walls that you drilled the holes 1 ½” from the sides.

Step 6. Then, switch to a smaller drill bit and drill halfway through the wooden strip.

Step 7. Repeat step 6 on the other wooden strip.

Step 8. Next, screw some small Philips head screws through the holes in Plexiglas and into the wooden strips to hold the wooden strip firmly in place.

Step 9. Do step 8 again to the other wooden strip and Plexiglas wall.

Step 10. Then, take the last Plexiglas wall and place it on one of the wooden strips attached to a Plexiglas wall.

Step 11. Next, repeat step 6 on this Plexiglas wall.

Step 12. Then, repeat step 8 on both sides of this Plexiglas wall.

Step 13. After that, cut two pieces of double-sided tape measuring 24” long.

Making the train:

Step 1. First, cut a piece of wood that measures 3 ½” by 3 7/8”.

Step 2. Next, cut two pieces of double sided tape measuring 3 ½”.

Step 3. Then, put one piece of double sided tape along the side that measured 3 ½” on the wood block.

Step 4. Next, cut 7” out of one of the magnetic strips.

Step 5. Then, cut that in half and end up with two strips measuring 3 ½”.

Step 6. Finally, place those two magnetic strips along the double sided tape.

This now completes the Maglev Train, if you would like to make the train float a little higher, put two magnetic strips on the bottom of the Plexiglass that is in line with the double sided tape that is on the track.

Learn about magnets

Flash game on magnetism