LB: Trial 1 Procedure

LB: Trial 1 Procedure 

Research Question: Does the process of gelatinisation cause the GBR to float?
Hypothesis: The higher the surface area to volume ratio, the faster the GBR floats in water.

Steps

   1. Measure out 100g of rice flour and water using a weighing scale, mix until evenly distributed.

Dough after mixing

   2.  Divide the dough into 6 parts, 4 parts of 40g each using the scale and 2 parts of 20g each using a spring balance.

Use cling wrap to prevent the dough from sticking

Keep adding dough, then press the lumps together when the amount is correct

3.  Roll all parts into balls. Then, evenly flatten 2 of the 40g balls until about 1 cm thick, leaving the rest untouched.

4.  Mark 1 GRB from each category (40g flats, 40 balls and 20g balls) with a dot of green dye. 
5. Lay all GRB on black paper covered with plastic, with a ruler in sight, and then take a photo from directly above.

This photo will be used for measuring surface area 

6. Individually wrap the 2 20g balls in cling wrap and place them inside a plastic bag. Squeeze out remaining air before twisting the bag closed.

Due to the cling wrap, the balls will not stick together

7. Fill a displacement can with water, and slowly submerge the plastic bag while using the 100ml measuring cylinder to catch the displaced water. Record the volume and repeat steps 6-7 for the other two pairs.

Place the can on a flat elevated surface, e.g. kitchen sink

    8. Using a 250ml cylinder, pour 750ml of water  into a pot. Put the pot on a hotplate set to 200°C and start the stopwatch. When the water has begun to boil, slowly lower all GRB into the water with a strainer.

The water should take about 3 minutes to boil

Make sure the GRB are not sticking together

      9. Stir continuously with the strainer and record the time it took for each GRB to float. Turn off the hotplate when all GRBs are floating.

The white 20g ball floated first.

    10. Using the strainer, transfer all GRB into a plate while making sure they are not touching each other (prone to sticking) and leave them to cool for 30 minutes.

11. Repeat step 5. 

12. Repeat steps 6-7, but directly slipping the GRBs into the displacement can without wrapping them. 

13. Weigh each GRB with the spring balance again.

LB: Experiment Procedures

LB: Experiment Procedures

1. Apparatus/Materials
2. Recipe
3. Steps

List of Apparatus/Materials*

1. 250 ml measuring cylinder, markings from 22ml-250ml per 2 ml
2. 100 ml measuring cylinder, markings from 10-100 ml per ml
3. 1 kg spring balance, markings per 20 g
4. 15 cm plastic ruler, markings per cm
5. 30 cm metal ruler, markings per cm
6. Mercury laboratory thermometer, markings from -10-110°C per 1°C 
7. 1 piece of A4 black paper
8. Metal water displacement can
9. 5 kg weighing scale, markings per 40g
10. Utensils (metal pot, strainer, plate and knife; wooden chopsticks)
11. Tap water at 27 °C 
12. Assorted Star Brand food colouring**
13. United Foodstuff glutinous rice flour**
14. Flying Man Brand cornflour**
15. Glad cling wrap**
16. Pen and paper
17. Calculator
18. Camera
19. Sumyeeta SD20B3 induction cooker
20. Stopwatch
21. HM-HDPE brand plastic bags
22. Yihua SF-400 series kitchen scale
23. Standard pack of poker cards 

*markings starting from 0 unless otherwise specified

**purchased from NTUC Fairprice 

Recipe

The ratio of water to glutinous rice flour by weight in the GRBs is 1:1. A dusting of corn flour was used to prevent them from sticking to the plate and food colouring was added to differentiate individual balls.

LB: Introduction

LB: Introduction

This is the link to the proposal for this project and this is the link for the brainstorming excel sheet. I will post tagged updates, most relevantly#lab book, as the experiment progresses. An explanation of the underlined words, usually science processes, can be found in the proposal, as well as at the bottom of this post. Do note that this journal is picture heavy, and will take time to load. 

The general structure is this: procedure, then results and discussion for each trial, interspersed with one-offs like the glossary. That said, the results post, especially for the earlier trials are going to be simple, tables and bar charts, because I don't think its worth the effort to analysis in-depth data that is known to be inaccurate. At the most, if will be to try out a particular method before using it on the final data.

The back story is that while cooking glutinous rice balls (GRBs), aka tangyuan, I've noticed that they sink initially, then float to the top as they are cooked. It's been niggling at me as to why, so when I was told to do a science project I naturally thought of this.

GBR in ginger sugar water with black sesame filing

GRBs do come in many flavours and soups, but I will be using plain flour, water and minimum food colouring, so as to distinguish samples to reduce the number of variables involved.


P.S.  

No:	Term	Meaning
1.	Gelatinisation	When starches are heated with water in cooking, individual grains absorb water and expand. This happens around 55 to 80°C, is irreversible and also increases the volume of the food,
2.	Upthrust	When an object is submerged in water, an upwards force called upthrust will acting on it and the amount of upthrust is proportional to the weight of water displaced. Hence if that object expands and displaces more water, more force will be pushing it up than before.
3.	Surface area to volume ratio	When an object expands, its surface area also becomes larger and surface area to volume ratio smaller. An increase in surface area is proportional to how efficiently it absorbs heat. Out of two foods with the same volume and mass but different shape, the food with the larger surface area will be cooked first.
	Glutinous rice	Contains more amylopectin than non-glutinous rice, exhibits properties such as an increase in viscosity ("stretchy/stickier...") and translucency after cooking. Becomes less dense.
	Correlation	Statistical relationship between two sets of data; does not imply causation

Introduction

Introduction

This blog is meant to run concurrently with a scientific experiment, as an online journal in a sense. It's "essential drafts, photographs and data" has to be "easy to follow" and honestly that is about the vaguest instructions I've heard in a while. What does that even mean anyway, bouncing cartoon tangyuans (BCTs) are banned because they're not essential? BCTs are not banned because my teacher "is not that strict"? BCTs are required to engage the reader? I really don't know.

So I've decided to split mine. Posts beginning with LB (for lab book) will be, well, the actual lab book. With aforementioned entries on experiment progress and couched in my best try at scientific language. All the other posts, e.g. this one, are rather informal.

well sorry, but I like hearing the sound of my typing, and usually ramble a lot, and can't help but think it diminishes my interest and enjoyment (and this is a student's interest-driven project) if I can't talk about the qualitative/irrelevant data like my experience conducting the experiment, yet at the same time I really am unsure about that rubric, so yeah...please tolerate., there's no need to actually read non-LB if you don't want to.

For convenience's sake there are tags as well, e.g. again, lab book. Have fun reading, good luck, and thank you!


Edit 15/7/12: from what I have seen of other's blogs and heard from my teacher, non-scientific language can be justified by wanting to be accessible to peer reviews. So yes, I also don't want to confuse anyone especially when they are already confused (sorry Charlotte).

Even if they're not the experiment, the people around you who've put up with being (repeatedly) confused are equally crucial to the project, so thank you very very much in no particular order 
Zhi Rui (reader no 1 from the get go), Kristal, Nicole, Jia Yang (yes I do in fact know I smell great like flour), Yuan An, Ms Tan, Ms Chionh, Mr Ooi , Mr Ali, Shermaine, Amy (photography skills of awesome in the classic sense), Daneel, Kellie, Jia Wen and family (oh your lovely lovely weighing scale), Laura and Charlotte and everyone else. Most importantly: Mum.