First Experiment

⚡⚡⚡First Experiment⚡⚡⚡

Experiment Title

How does the ratio between yeast and flour affect the fluffiness and size (height and width) of mantou?

Hypotheses

💨 1:60 is the optimal ratio to produce the fluffiest mantou

💨 No correlation between Y-F ratio and height

💨 Negative correlation between Y-F ratio and width (Higher ratio leads to shorter width)

Before Cooking

5W

What to prepare?

🧸 Ingredients: All-purpose flour, sugar, salt, milk, instant yeast, oil

🧸 Equipment: mixing bowls, aluminum foil, steamer, roller, wet towel, utensils

Who conduct?

💥 Lam Ting Hin, Justin

Where to obtain materials?

💫 Ingredients purchased from market: All-purpose flour,

💫 Ingredients purchased from supermarket: milk, instant yeast

💫 Ingredients obtained from home: sugar, salt, oil

💫 Obtain equipment and cook at: My Home Kitchen

When conduct?

🌡️ Mar 15 2020 14:30pm

🌡️ Temperature: 21.4 °C

🌡️ Humidity: 63%

Why conduct?

💦 Investigate in the effects of change in yeast-to-flour ratio on the fluffiness (gas bubbles, softness, skin smoothness) and size (height and width) of a steamed mantou, in hopes of identifying an optimal yeast-to-flour ratio for the fluffiest mantou.

💦 Mantou is a kind of bread which allows me to observe the fluffiness easily since it only consists of the basic ingredients of a bread (less affected by other variables).

Variables

Independent Variable	Dependent Variables	Controlled Variables
Ratio between yeast (Y) and flour (F) 🍞 1:30 (10g Y:300g F) 🍞 1:40 (7.5g Y:300g F) 🍞 1:60 (5g Y:300g F) 🍞 1:80 (3.75gY:300gF)	Fluffiness and size of mantou 🍞 Fluffiness: gas bubbles, softness, skin smoothness 🍞 Size: height and width	Other variables other than ratio between yeast and flour, e.g. 🍞 Type of ingredients 🍞 Amount of other ingredients 🍞 Mixing, kneading, rising and steaming time 🍞 Cooking environment and temperature 🍞 Size of mantou before fermentation

During Cooking

Y-F ratio will be changed as follows:

🦄 1:30 (10g Y:300g F)

🦄 1:40 (7.5g Y:300g F)

🦄 1:60 (5g Y:300g F)

🦄 1:80 (3.75gY:300gF)

Experiment Details

🌟For tidiness, ALL photos and clips are condensed into a video. Watch the below video first before proceeding🌟

The experiment was repeated 4 times, each with different yeast-to-flour ratios.

Yield: 4 servings (~10-12 Mantou)

Preparation Time: 2 hours 14 minutes

Cook Time: 27 minutes

Total Time: 2 hours 41 minutes

Ingredients

All-purpose flour	300g
Sugar	30g
Salt	2g
Milk	180ml
Instant yeast	3.75g/5g/7.5g/10g
Oil	10ml

Steps

1️⃣ Preparation

2️⃣ Place the flour, instant yeast and sugar into a mixing bowl. Gently mix it.

3️⃣ Slowly add oil, salt and warm milk. Continue to knead and add milk as a dough ball is formed. If it is hard and dry, add more milk. If it is too wet and sticky, add more flour. At the end, the dough ball should be smooth, soft and non-sticky.

4️⃣ Put the dough into a flour-covered bowl, then cover it with plastic wrap or wet towel and set aside to rest. For experimental purpose, some 4cm*4cm*4cm cubes are cut from the dough to control the size of mantou before fermentation. Let the dough rest for around 60 minutes or until it doubles the size, whichever earlier.

5️⃣ Label the 4 doughs and the control mantou brought from a baking store to ensure correctness.

6️⃣ Place the dough on a flour-covered workstation. Roll it into a 3-4mm thick rectangular log. Flatten the log using a rolling pin.

7️⃣ Starting from the long side of the dough, roll it towards the other end to form a log. Slightly brush some water at the end to tighten the log.

8️⃣ Slice the log into pieces of 4cm and place them on an aluminum foil. Lightly dab the surface of the buns and the separated piece with some milk to smooth the surface. Then loosely cover it with a damped towel and let it rest again for 30 minutes or until it doubles in size, whichever earlier.

9️⃣ Put the buns into the unheated steamer. Leave the lid with a little gap. Steam on medium heat for 20 minutes. After turning off the heat, keep the lid on for extra 7 minutes to prevent the buns from becoming saggy.

After Cooking

What to investigate?

🐾 Investigate in the effects of change in yeast-to-flour ratio on the fluffiness (gas bubbles, softness, skin smoothness) and size (height and width) of a steamed mantou.

When to measure result?

🐣 Measure experiment result immediately after mantous are steamed

How to measure?

🐤 For each trial, 4 mantous are used for result measurement. Their heights and widths are averaged into the final result for fairness.

🐤 The results of fluffiness are concluded after observing 4 mantous of the same type and comparing with the control.

🐤 For fluffiness, the result is concluded after observing all 4 mantous.

🐤 Use a ruler to measure the height and width of mantous immediately after steaming.

🐤 Slice the mantou into half to observe the gas bubbles and skin smoothness of the mantou, then slightly press from the top to observe the softness.

Analysis

Measurement Table

Y-F Ratio	Measurement Time	Height (cm)	Width (cm)
1:30	17:16	4.1	6.8
	17:17	3.9	7
	17:18	4.1	6.5
	17:19	4	6.6
	Average	4.025	6.725
1:40	17:23	4.3	6.7
	17:24	4.1	6.3
	17:25	4.2	6.5
	17:26	4	6.1
	Average	4.15	6.4
1:60	17:33	3.9	6.2
	17:34	3.8	6.2
	17:36	4.2	6.1
	17:37	4.2	6.1
	Average	4.05	6.15
1:80	17:40	4	5.1
	17:41	3.8	5.2
	17:42	4.1	5.6
	17:43	4.4	5.2
	Average	4.075	5.275

Height vs Y-F Ratio Table

🦢 No obvious correlation between DV and IV, so the hypothesis is accepted.

Width vs Y-F Ratio Table

🦆 Negative correlation between DV and IV, so the hypothesis is also accepted.

🦆 Reason behind: When the dough ferments, it tends to grow horizontally. So, the more yeast used, the wider the dough grows.

Fluffiness Table

Y-F Ratio	Gas Bubbles	Softness	Skin Smoothness
1:30	Many gas bubbles scattered	Extremely easy to squeeze	Roughest
1:40	Quite many gas bubbles scattered	Easy to squeeze	Rough
1:60	Average gas bubbles scattered	Need to apply slight force to squeeze	Smooth
1:80	Only a few gas bubbles present	Need to apply larger force to squeeze	Smoothest

Reasons behind:

🍀 As the proportion of yeast increases when amount of flour is kept constant, more tiny air bubbles are formed and scattered around the whole mantou. This creates more air pockets, thus enhances the softness of the bun.

🍀 As for skin smoothness, the degree of fermentation intensifies when the ratio decreases, leading to more air bubbles and holes. As a result, the skin becomes rougher.

Possible Errors

🍂 Manual Error. Hand gestures manipulated the size of mantou before steaming, leading to inaccurate size measurement.

🍂 Improvement: Fill the dough into a mold for size control

🍂 Inconsistent ingredients amount and time. May have slight discrepancies in ingredients amount and time throughout the 4 trials.

🍂 Improvement: Use more precise tools for measurement, e.g. syringe, electronic scale,…

🍂 Space limited during steaming. The buns are quite packed on a plate during steaming, which may impact their sizes.

      🍂 Improvement: Steam fewer buns at a time and plate them dispersedly.

🍂 Subjectivity. When measuring the fluffiness based on observation, subjective errors may occur as I am the only experimenter.

🍂 Improvement: Include more experimenters and allow others to feel the texture.

Control Variables really kept controlled?

🌍 Some of the variables remain controlled, e.g. type of ingredients, cooking time…

🌍 Yet, in a household environment with simple equipment, some variables are hard to be controlled, e.g. exact amount of ingredients, temperature, humidity, kneading force, etc.

Minimizing Errors

🌠 To finish the experiment within the shortest period of time to lessen environment variation.

🌠 Double check each procedure to reduce manual errors.

🌠 Use quality and professional equipment when possible.

🌠 Do experiment in a controlled environment if possible.