I've been getting more involved in kitchen activities lately in the COVID-19 pandemic has urged many to get their hands dirty while making banana bread, cinnamon buns, Dalgona coffee... the trends keep changing!

The brief

We've used traditional pressure cookers since I was a kid, it's been part of my growing years and like most Indian families we count the number of whistles to know if the food was cooked. But even after all these years listening to cooker whistles at home, it still feels annoying when mom asks me to keep a lookout for the cooker whistles, and it has become more apparent during the lockdown. I constantly found myself running around the house asking people if they heard any whistles, even burning the rice couple of times. But it was different this time. It wasn't a trivial problem anymore, now that my design instincts had kicked in. I knew I can't be the only one facing these issues! So I set out on a journey to solve the infamous whistle conundrum.

Research Study

In order to validate my hypothesis, I put out a survey to understand rice cooking methods adopted in Indian kitchens. This was the first part of my mixed-method approach towards understanding my stakeholders. The results were in line with my assumptions, with some interesting findings.

Rice cooking methods in India

Majority of Indian households still use traditional whistle cookers, with a surprisingly decent adoption of electric cookers. But what really shook me was that people still used regular open utensils to cook rice. Below is a Sankey Plot which breaks down people's experiences with their cooking methods.

Rice cooking process in India

We see that 54% of the people who used traditional whistle cookers found it problematic, in terms of overcooking, undercooking or burning the rice because they missed the cooker whistles. Something to note is that the survey was filled by young adults who are 20-27 years old. Most of them were students who are currently studying or recently employed, and don't regularly involve in kitchen activities, which explains why most respondents found it problematic, because one would assume that years of cooking rice in pressure cookers would've tempered the learning for most house cooks.

Findings

The interviews and the survey data gave me some really interesting insights:

• The duration of the whistle is important. There are times when the whistle comes for a jiffy, but this is something which is not counted towards the tally.
• The responsibility of looking after the pressure cooker is usually given to someone when the cook has some other work. For example, if mom has to get ready for work or a zoom meeting, she will ask her daughter to keep a look out for the cooker whistles, who reluctantly agrees, but forgets.
• In independent houses and villas, with kitchens being on the ground floor and rooms being usually on the next floor, it's almost impossible to hear the whistles. This forces family members to come down and sit somewhere near the kitchen and continue their work if they are asked to switch off the cooker after a few whistles.
• People said they would rather continue working on their assignment submission, continue their yoga session, watching TV or binging Netflix if they weren't asked to count the whistles.
• Indian families do not trust the pasteurization process which commercially produced milk goes through, and boil the milk before using it. When asked if there are other problems they face in the kitchen, many survey respondents mentioned they forget to switch off the gas stove and the milk almost always either overflows or burns. Although quite relevant, it's a problem to solve for another day.

Finally, the running narrative among all the participants was that they don't like standing in the kitchen and waiting for the whistles. I created two personas based on these findings, which helped me design for my users better.

Personas based on findings

As a next step, I decided to conduct a literature review to delve into the nitty-gritty of pressure cookers, their history in India, and what is considered to be the best way to use them. So I decided to conduct a little experiment to find out how much energy do we end up wasting by letting the whistles go off.

Experimentation

I did some math and calculate the energy consumptions for the top two cooking methods my participants practiced,

• The correct way of using pressure cookers, where you build up the pressure by keeping it on high heat and then putting it on simmer to let the steam cook the food.
• The relatively convenient way of just letting the cooker do its thing and count a set number of whistles based on the type of food.

The idea was to see if there is a significant difference in energy consumptions in both these techniques. I used an induction cooktop to measure the energy used for each method, and repeated the experiment 2-3 times for both methods to get an average estimate. The below infographic goes into the results of my experiments.

Experiment findings with cooking energy efficiency

The plot shows the experiment conducted for different power levels, and it tells us that the energy consumption is almost the same for both the methods, which means you don't save much energy by doing it the right way. This only tells us that forcing people to change their mental models about using pressure cookers isn't wise, and the correct path to solving this is to design a solution which will help the younger generation Indians count the cooker whistles easily.

Prototype Development

There are two core components to the prototype development:

• Seamless recognition of the cooker whistles
• Counting the whistles and notifying the user

These activities laid out a framework for the data collection process, required to train a robust recognition model which can accurately detect and count the cooker whistles. The data collection took around a month, where I used my smartphone's microphone to record cooker whistles, while emulating the settings in which the user will be using the app. The audio files were then manually parsed to extract audio snippets, labelled as "Whistle" and "Noise", and standardised to 16kHz sampling rate. For model building, I used the createML framework's sound classification template to create a robust yet small-sized Neural Network (at just 4.6MB!) which was able to classify cooker whistles with 99% accuracy!

I started designing the interfaces. Given the utilitarian purpose of the app, I wanted to make it as simple as possible for anyone to jump in and start using it.

Branding of the Whistl

I used black as my primary colour, tints of black to represent hierarchy and San Francisco as my primary typeface as people are usually more comfortable with the system font.

Homescreen & Mainscreen of the Whistl

Testing

In my first prototype testing, I got the following feedback from users:

• Some people said they preferred getting a phone call when all whistles have been counted.
• The ability to notify someone is useful, but it will be better if they get notified through an alarm of some sort, as they miss out on a SMS or email notifications.

Phone calls and alarms are naturally something we prefer as they are relatively more intrusive and better at grabbing people's attention. But notifying someone else through an alarm would require a client app installed on the recipient who is to be notified, which complicates the app's functionality. Instead, I added an option where the user can notify someone through an automated phone call, which is simpler to use and implement. After making these changes, I designed the final UI.

Notification flow testing of the Whistl

Looking further afield

As the Indian smartphone market is heavily dominated by Android users, I have planned on rewriting the app in Flutter, a cross-platform development framework, to reach a wider market and have a bigger impact.

It might seem like this study might have been an overkill for the problem in hand, but through this laborious process, I was able to uncover various kitchen practices in India, debunk myths about how pressure cookers should be used and create a robust and accurate app for helping people.

We have problems everywhere, it's just a matter of noticing them and solving them.