The Use of Fluids – Chapter 5
Key Ideas
Understanding the properties of fluids is an important aspect of developing technologies and perfecting the design of structures to improve safety and reduce damage or breakdown due to wear and tear
Objects immersed in a fluid will experience pressure (a force of gravity)
Forces can be transferred through confined fluids
Pressure, Temperature and Volume of a fluid affect each other
Machines and other devices that use fluids can make work and movement easier – hydraulics & pneumatics
5.1 Career Profile: Food Scientist
Viscosity and the Chocolate Factory
Summary:
Food Scientist – research and development (aka R&D; testing) of improvement of chocolate making process
Temperature and ingredients greatly influence viscosity
Regular testing can improve quality and dependability of product
Viscometer measures viscosity – a spindle attached to a motor and gears that help to measure the force needed to rotate the spindle through the viscous mixture
Try This Activity: Lab Report
Lab Title: Factors Affecting Viscosity of Chocolate
Question: Do the ingredients used in different types of chocolate affect the Viscosity and Texture?
Hypothesis: If chocolate contains less additives (is more pure cocoa) it will have a greater viscosity and be of a higher quality texture in terms of smoothness.
Materials:
Heat Source – stovetop / electric element / microwave
Different types of chocolate to compare
Sample A ________________________________
Sample B ________________________________
Sample C ________________________________
Water if using the boil method to melt chocolate
Measuring Cup / Beakers
Stir stick
Heat resistant gloves
Procedure:
Melt chocolate using preferred method – the boil method is the best way to ensure that the chocolate does not burn
Boil Method:
Place solid chocolate sample into glass container
Place glass container into pot of water
Boil Water and chocolate until the chocolate melts thoroughly
Time this process if you would like more detail (be careful to measure heat (temperature) and maintain consistency of data)
Stir each sample to compare viscosity – record results here:
Sample A __________________________________
Sample B __________________________________
Sample C __________________________________
Take a liquid spoonful of chocolate and drip over wax paper to compare flow and pooling
Record Data (as above)
Observe the flow rate of the spoonful – carefully and slowly tip the spoon and count the seconds it takes to finish – record the height between spoon and wax paper to ensure consistency between samples’ flow rate.
Texture: Gritty, Smooth, Chunky, Crystals ….observations only
NEVER TASTE ANYTHING IN THE LAB
USE SAFETY EQUPMENT TO AVOID BURNS
Data and Observations:
-Time for chocolate to melt:
Sample A
Sample B
Sample C
-Perceived Viscosity based on stirring of mixture:
Thick Medium Thin
Sample A
Sample B
Sample C
-Observed Texture:
Smooth Chunky Gritty etc.
Sample A
Sample B
Sample C
Use a Table to compile and compare data:
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Properties of Chocolate |
Sample A (Bakers) |
Sample B (Chippits) |
Sample C (Hershey) |
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Ingredients |
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Viscosity |
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Texture |
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Melt Time (Minutes) |
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Flow Rate Estimate (Tablespoon/Time) |
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Analysis:
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Conclusion:
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Applications:
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