Project Proposal (Kiannie)

https://www.seriouseats.com/2014/06/make-better-pourover-coffee-how-pourover-works-temperature-timing.html

Topic:

Observing the effect of coffee grind size on time needed in hand-drip coffee and determine its effect on acidity/taste

Introduction:

   As a coffeeholic, you may like to make a cup of coffee yourself and enjoy it at home. Hand-drip coffee may be a good choice for you. However, have you wondered what grind size you should use when you are making your own cup of coffee? It is easy to find a " perfect grind size " for each type of brewing method on the internet. However, is it really " perfect " for everyone? Have you ever thought of how grind size affects your coffee? Thus, the aim of the project is to observe the effect of grind size on the taste of coffee.

Experimental Test 

Who?

Yiu Cheuk Laam (Kiannie)

What?

To test the effect of grind size on dripping time and eventually the taste of coffee

Where?

Coffee shop/Home

When?

Mid of March

Why?

To find out how grind size affect the taste of the hand-drip coffee.

How?

Make hand-drip coffee in the same way with different grind size of coffee. Record the time used to filter the coffee and test the coffee with pH paper or taste the coffee right after stirring. 

Material needed:

20g Coffee bean 

300ml Hot water (75g/serving)

Cone filter

Cone shape pour over dripper

Burr grinder

Gram scale

Slow pouring kettle

Thermometer

Instructions: Step by step Receipe  <--- click here

Independent variables	Dependent variables	Controlled variables
- Different grinding degree     4 degree is tested:    1,5,9,13 respectively            (1 is the finest,13 is the coarsest )	-The dripping time of coffee	1. The weight of coffee used 2. The temperature of the water 3. The time require for resting   4. Water-to-coffee ratio 5. 3Bicarbonate concentration in water 6. Pour-over skills     ( 4Control your flow rate )

Results:

1. Compare the time requires for each grind size.

2. Find out the correlation between time and grind size in hand-drip coffee.

3. Test the acidity of coffee in each grind size with pH paper/taste of coffee under blind test.

4. Further elaborate the relationship between grind size and the taste of coffee.

https://www.perfectdailygrind.com/2015/11/coffee-science-whats-acidity/

The science behind:

    Grind size is an important factor in making a cup of coffee. It refers to how fine or coarse the coffee bean is ground into. Difference grind size makes a difference in contact time, extraction rate and flow rate. These factors are intercorrelated. The finer the coffee, the larger the surface area provided. The larger the surface area, the higher extraction rate and lower flow rate of water is required. The higher extractions rate, smaller contact time is needed as well. In order to obtain a well-balanced coffee, many factors should be controlled. Or else, over-extracted and under-extracted may occur which results in unpleasant bitter taste or weak taste.

   The experiment observes the effect of grind size on the taste of coffee. The time requires for hand-drip coffee in different grinding size is recorded to see how grind size affects the dripping time and eventually resulting in different taste of the coffee.

By Yiu Cheuk Laam (3035564756)

Reference

1. Martin T. Coffee grind size: Why it matters and what you should be using. CNET. 2015 Dec 22. https://www.cnet.com/how-to/coffee-grind-size-why-it-matters-and-what-you-should-be-using/

2. Coffee grind size. https://coffee-brewing-methods.com/entity/grind-size/

3. The chemistry and physics behind the perfect cup of coffee. SMithsonian. 2017 Sep 28. https://www.smithsonianmag.com/science-nature/science-behind-brewing-great-cup-coffee-180965049/
4. 47 tips to make pour over coffee like a barista. Handground. https://handground.com/grind/47-tips-to-make-pour-over-coffee-like-a-barista