THE CASE FOR SOFI

IN THE DYNAMICALLY EVOLVING WORLD OF COFFEE

Why SOFI is the South Indian Filter inspired brewer that India needs to stake its place at the forefront of specialty coffee design

We are thrilled to announce Aramse’s first-ever white paper — The Case For SOFI In The Dynamically Evolving World Of Coffee. This white paper is the amalgamation of all of our research, experiments and testing on the original South Indian Filter which culminated in our product, SOFI. We found it exceptionally hard to find resources, scientific research and communities around the South Indian Filter when we first started this journey and so now, we want our findings to be made available in the public domain. We think the South Indian Filter has been a diamond in the rough, with a few obstacles preventing its relevance and popularity for specialty coffee. We demonstrate how SOFI aims to solve a lot of those issues.

To read the PDF version (recommended), click on the button below or scroll down to read it online.

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KEY TERMS

Throughout this white paper, we will use the abbreviation SIF to refer collectively to all traditional South Indian Filters, regardless of material, brand, or regional variation. These include the widely recognized stainless steel or brass brewers used for generations across South India.

Our company, Aramse, designed SOFI, a modern reimagination of the traditional South Indian Filter. It is inspired by the principles of the SIF, but redesigned for versatility, consistency, and a broader range of brewing styles. Whenever we refer to SOFI, we are specifically speaking about this redesigned brewer.

I. EXECUTIVE SUMMARY

Why bother designing a Rs. 3,299 modernized brewer inspired by the South Indian Filter (SIF) when the market is flooded with c. Rs. 400 variants?

Coffee drinking in the South is synonymous with the South Indian Filter and the drink it is most often associated with, kaapi — a sugary drink made by mixing boiling hot milk with the coffee concentrate or decoction, and then frothed by pouring it from a height, back and forth between two containers. And yet, why do we see so few of these being used to brew specialty coffee? This question began to plague us 7 to 8 years ago.

We argue that the way coffee culture is progressing, the SIF is at serious risk of becoming a relic. If the brewer was an irrelevant object for the modern era, like say a cassette or even a CD, then leaving it behind would be understandable. This, however, is not one such object — it has a steep learning curve despite its simple appearance, but when done right, it produces a brew with a flavour profile that is truly unique. This, in addition to key features like portability, sustainability, multi-functional design features, and a rich cultural tradition is why we think a brewer like this is worth preserving.

SOFI is our answer to prevent this brewer from becoming obsolete. The name is a portmanteau of ‘South’ and ‘Filter’. It was important for us that the reimagined SIF that we designed for specialty coffee, have a distinct and short name. This seemingly small detail is, in fact, crucial for setting it apart from the several other brewers classified as SIFs on the market, allowing for communities to form around it.

First, we lay a framework for which features of the current available South Indian Filters lend themselves to market obsolescence. We argue that for India to be viewed as a design thought leader and powerhouse, Indian companies and entrepreneurs need to strike the fine balance between nostalgia and modernising our objects to remain relevant for a very dynamically evolving market, like coffee.

Next, using empirical evidence, we substantiate the uniqueness of the South Indian Filter flavour profile, an extremely important characteristic for the world of specialty coffee brewers. Finally, we designed a brewer that solved the issues faced by us, and found that we were not alone. This was proof of concept that a standardised solution alongside additional modifications, like SOFI, is what consumers and the world of coffee need in order to have a SIF-like brewer be relevant for the next waves of coffee — both specialty and otherwise.

II. PROBLEM STATEMENT

India’s coffee consumption has been steadily increasing from 84,000 tonnes in 2012 to 91,000 tonnes in 2023. Whilst our per capita consumption is still very low compared to Western coffee consuming countries, there is great potential for this upward trajectory to continue. With Gen-Z and millennials consuming less alcohol than previous generations, coffee is in a strategically significant position to be the aspirational social beverage of choice. The South still has the highest penetration of 75%, but the North and West show robust penetration with 48% each.

A similar story exists outside of India in terms of increasing demand for coffee, especially specialty, with consumers seeking novelty in flavour profiles. Despite growing interest in coffee, both domestically and internationally, very few outside of traditional coffee drinking homes in South India use the SIF in the context of modern coffee — social, dynamic, community based interactions including recipe sharing, brewing and drinking, with high engagement content on social media channels, and a desire for curated offline experiences.

With these many tailwinds, a product like the South Indian Filter, one from a coffee-producing country, and with rich cultural significance should be poised to gain popularity that transcends state boundaries. However, we argue that due to the confluence of several factors, it has created the perfect storm for why this brewer could, in fact, become obsolete.

The current South Indian Filter Coffee experience is largely restricted to two scenarios — first, within South Indian homes that have been drinking coffee for decades. Here, every household that has historically used the filter, has their own heirloom recipe often nicknamed the “best coffee recipe in the world”. Second, filter coffee enthusiasts frequently drink batch brewed filter kaapi at darshinis, or quick, self-serve restaurants.

Most of the available SIFs on the market, despite their uncomplicated appearance, are challenging to brew with. This is because there are no documented, foolproof brewing techniques, and there is a lack of consistency in specifications from brewer to brewer. After several experiments with different SIF brewers, we nearly quit brewing specialty coffee with it. However, when I brew goes well, it produces a flavour profile like no other, and this is the biggest reason we think it deserves a space on coffee bars around the world and not just those in India.

So, why do we see so few of these brewers outside of the homes that grew up with it? This question answered itself after we published our first South Indian Filter brew guide exactly 5 years ago. Immediately after release, we were inundated with questions which, much to our surprise, were hard to troubleshoot. We quickly realised that it was because we did all of our testing on our SIF. The number of different variants of the SIF that exist on the general market are extraordinary and they all go by the same name. There is no standardisation across shape, number of holes, hole size, height, diameter, etc. This meant, for all intents and purposes, we were trying to help people who weren’t brewing with the same brewer.

Image 1. Examples of brewers categorised as ‘South Indian Filters’

In practice, recipe sharing is extremely difficult unless you learn it by osmosis or close repetition on the same brewer. The SIF experience can therefore become an isolating one in the modern world of coffee communities.

III. BACKGROUND

The Indian subcontinent’s vibrant and rich history is one of several parallel stories, cultures and languages, rarely consistent across the post-independence landmass we refer to as India. This, combined with our long-endured, gruesome colonial repression means that Indian products and objects, their significance, and the etymology of their names were rarely documented in detail unless required for consumption by our colonisers.

It doesn’t take too many Google searches to quickly see that most Indian coffee history writing points to the short story of Baba Budan, a Sufi saint credited with smuggling coffee in the 17th century to Chikmagalur, India — where the highest coffee-growing peaks, Baba Budan Giri, were named after him posthumously. Whilst a fascinating story, it often feels like the entirety of coffee history in India — from growing, brewing and drinking culture — has been reduced to this one story.

Given this background, it is unsurprising that we don’t know very much about the South Indian Filter. A feature apparent even beyond the realm of coffee is that where there is good Indian design, there is often poor documentation. Therefore, it is important for us to lay the foundation for this paper by highlighting some key SIF features using a design lens, including:

A fully stainless steel build which can last a lifetime. In addition, not needing paper filters makes this one of the most sustainable brewers — especially compared to plastic ones.
Extreme portability. It’s travel-friendly, thanks to its durability and the fact that it doesn’t require electricity.
A unique flavour profile because of the combination of slow percolation through extremely fine grounds.
The concentrate, often called a decoction, is much like espresso and can be used in a similar way to make both milk drinks, and be diluted down to be consumed black. This makes the SIF a much more versatile brewer than it is currently being used for, exclusively to brew kaapi.
A metal filtered brew which offers high clarity even without paper filters — with low agitation brewing like we recommend with this brewer, the coffee bed acts as an excellent self-filter.
Being fully self-contained and multi-functional:
- A lid whose primary function is to retain heat, thereby increasing the slurry temperature during the brewing process. This lid can also be used to collect fines when distributing the coffee bed pre-brew, and as a drip tray post-brew.
- A collection chamber for the brewed coffee which can double up as a drinking device.
- A curved filter, whose unique benefits are explained below:
  - With a curve, the coffee bed depth decreases toward the outer edges.
  - Since flow resistance in porous media (like ground coffee) is proportional to bed depth, the thinner areas near the edges offer less resistance to water flow.
  - This balances out the extra hydraulic resistance introduced by viscous drag near the brewer walls.
  - The result is a more even extraction across the entire bed resulting in brews with higher extraction yield %, higher perceived sweetness and more balance, compared to brews on our flat-filter prototypes.
- It was a no-bypass brewer well before the current popularity of no-bypass brewers like the Tricolate and Orea Z1.

This design thinking can be extended to the drinkware — davara and tumbler — often associated with kaapi.

The flat protrusion on the cup makes both handling an extremely hot drink and pouring without spilling much easier.

It wouldn’t be a stretch to say that if the South Indian Filter was crafted in the Global North or the Western World, it would be the subject of an entire design module at universities. And yet, we know very little about its provenance — if it came before or after the Vietnamese phin, whether the two had anything to do with each other, or even who designed and made the first SIF. This would be akin to the iconic Eames chair just being referred to as The American Chair.

IV. PROPOSED SOLUTION

1. Cultural Preservation

Preserving a brewer like the South Indian Filter is an important part of preserving Indian culture. There are two main benefits we note for the preservation of historical objects:

Knowing where we come from gives us a foundation and rooting to establish where we want to go collectively as a society.
It helps countries like India be seen as thought leaders, and not just producers of raw material, i.e., green coffee. However, in order for this to happen:
- We need to experiment and document right from farm level knowledge to knowledge capabilities around brewing and drinking coffee.
- Indian products and design need to be viewed outside of the kitsch and novel experiences they are associated with in the Western world. By modernising them, they can exist in the day-to-day experiences of people’s homes, transcending their current most common use case: satiating nostalgia.

2. Distinction Between Brewer and Drink

We believe that the crux of the issue currently facing the SIF is that the brewer and the drink it is often used to brew, kaapi, are viewed as mutually exclusive. To us, this would be akin to viewing an espresso machine as a cappuccino brewer. This analogy is of particular significance because the concentrate or decoction brewed with the SIF can be used like espresso — you can dilute it with water to make an americano-style drink, add textured milk to get a cappuccino or flat white-style drink, or even add ice to make cold coffees.

Further, the history of the South Indian Filter has been mostly about the drink, kaapi, and its preparation — most of what has been written has been written about the addition of chicory, boiling milk with sugar and frothing it from a height to make ‘stretch coffee’ etc. Little attention has been paid to what we think should be the hero — the brewer.

One of our biggest missions at Aramse has been to dissociate the brewer from being used to strictly brew kaapi. To us, this is one of the most important ways to make the SIF more popular. It instantly transcends just one drink, immensely increasing its global appeal as audiences can see it for all its true potential — a versatile, travel friendly, sustainable brewer capable of brewing many different styles of drinks, some of which are truly unique.

3. Standardisation

When modernising the South Indian Filter, we had to answer 3 very important questions:

1. Can it make delicious coffee even by specialty standards?

The answer was a resounding yes — this realisation, very early on in our extensive testing process, is what drove our passion to increase the popularity of this brewer.

2. If it can make great coffee, then why isn’t it more popular?

As stated earlier in the problem statement, broadbased appeal of this brewer is greatly hampered due to the variance in specifications (i.e. size, material, shape, number of holes, to name a few). Everyone who owns a SIF, owns a different variant of it — a problem that is especially apparent when people need help with troubleshooting their brews.

3. What can we do to change that?

Standardisation is the foremost solution, followed by solving the problems specific to current SIFs. This led to the birth of SOFI — a brewer inspired by the traditional South Indian Filter, but reimagined for specialty coffee:

For starters, it has a unique name, removing any confusion about which brewer or variant you are brewing with.
The refined modern design has several benefits — for example, no sharp edges, a serious concern with many SIFs available on the market, means the collection chamber can be comfortably used as a drinking apparatus making it an extremely travel friendly brewer.
Every SOFI is made with 0.8mm gauge Stainless Steel 304, has a diameter of 73mm, with exactly 129, ~0.8mm evenly spaced holes to ensure even percolation, and has gone through 5 rounds of quality testing.
Handling the hot brewer during the brewing process has been improved with the inclusion of a heat-resistant band accessory.
A detailed, 10-step guide (See Image 2) is included in the box, creating a very low barrier to entry — this technique or recipe was developed over 2 years of testing and tweaking. Now anyone can brew a delicious cup of coffee with SOFI. To make it inclusive, we have simplified the technique so it can be replicated even with SIFs readily available on the market. This is to promote our ultimate goal of preventing this piece of history from becoming redundant.
It includes a WDT (Weiss Distribution Technique) Tool that is often used in espresso preparation. This tool has nine, 0.25mm acupuncture needles that comb through the coffee bed to break up clumps and distribute the grounds prior to brewing.
The box does not contain the “plunger” accessory that ships with traditional, market-available versions of the South Indian Filter. These are typically poorly manufactured with waste material, and during our extensive testing, revealed that they would often tilt and dig a hole in the coffee bed, causing severe channeling.
The SOFI design fixes one of the most common problems faced by users brewing with the classic SIF — airlock, causing stalled brews. With the introduction of two airflow vents, users can comfortably shut the lid and top chamber tightly without worrying about the creation of a vacuum.

Image 2. 10-step brew guide included in all boxes of SOFI

V. BENEFITS

SOFI began as a hypothesis for how to solve problems we faced with the South Indian Filter, and organically grew from thereon out. The biggest test of whether our hypothesis was, in fact, correct is if we achieved more broadbased appeal. The results have been conclusive — the original SIF has largely been restricted to one region of India for the greater part of a century. Conversely, SOFI is now being used by people in over 16 different countries, and of different nationalities. There is a rapidly growing community of SOFI users globally, brewing coffees not previously associated with SIF brews, such as light-roasts and non-Indian coffees. This has led to the creation of a Facebook group where users share knowledge and experiments which we cover in a later section.

After earlier referencing the fact that the SIF and therefore, SOFI brews a truly unique brew in terms of flavour profile, the next section dives into greater detail about what this means.

1. Brewing Style

The SIF is a percolation brewer much like other pour over drippers. The difference is the rare combination of espresso fine grounds, and slow percolation (usually approximately 6-10 minutes) to get a concentrated beverage. At 6-7.5% Total Dissolved Solids (TDS), this is the closest to espresso in terms of strength. After establishing this, further taste tests convinced us that the uniqueness of brews went beyond just strength, so we tested it scientifically.

Image 3. Cupping coffees brewed with the three different brew methods

2. Experiment - Comparing Brew Methods

We eliminated the differences in strength and extraction before comparing different brew methods to hone in on the flavour notes and attributes that each method highlights. We achieved this by using the same coffee to brew a V60, espresso and SOFI all to the same Extraction Yield percentage to +/- 1%. We then diluted the espresso and SOFI to match the TDS and temperature of the V60 before cupping the three brews blind. We also used the same grinder and kept the brew water temperature roughly the same to minimise the number of variables that could influence the taste. We did these tests with Indian and international coffees at varying roast levels and the results were very stark.

The best way to describe the flavour profile and mouthfeel of a SOFI brew is the combination of a perfectly dialled in espresso and an excellently brewed Orea.

Image 4. Spider charts comparing the flavour profile distinctions of the three brews

With SOFI, we noticed rounder notes with a more mellow acidity and with higher perceived sweetness, similar to other flat bottom brewers. Flavour notes skewed more towards ripe fruit, cooked fruit and chocolate. The V60 by comparison produced sharper and more pronounced acidity. In spite of being metal filtered, the SOFI brews had surprisingly high clarity, especially compared to the espresso, and unexpectedly not too far behind the V60. The SOFI brew had more body and juiciness compared to the V60, and overall more intensity of flavour making it similar to espresso in this regard. What really sets it apart, however, is the mouthfeel which is velvety smooth, and it is even more apparent when contrasted with the edginess that espresso can often have. The differences between the three brews were not subtle — which is why we have been beating the drum about the relevance of the South Indian Filter in modern coffee.

These flavour differences were noted when it was diluted down like an Americano. When left in its concentrated form, there is really nothing comparable to SOFI — and for consumers that enjoy milk based drinks, its brews are a real treat. The large flattish bottom with a very slight curve manages to produce syrupy, chocolaty brews with medium and dark roasts without extracting too much bitterness. This is in spite of the fine grind and longer brew times.

3. Broader Implications & Global Appeal

These findings from our experiments are in line with SCA’s findings published in issue 8 of the 25 magazine — that the shape of the brewer has a significant impact on the flavour profile and the notes that are brought to fore. That, combined with this brewer’s temperature decline over the course of the long brew seems to help create these lovely, unique cups of coffee.

Image 5. Issue 8 of 25 Magazine

This is also the first time, to our knowledge, that such extensive experimenting using a scientific method has been used to study South Indian Filter brews. Previously used exclusively to make kaapi, these experiments showcase the versatility of the decoction or concentrate that you collect in the bottom chamber.

Further Experimentation

Users are experimenting with SOFI in ways never done before with the traditional SIF, thereby promoting its global appeal.

Whilst the SIF has never needed any kind of paper filtration, for customers looking for quicker brews and better clarity, SOFI is compatible with popular paper filters used by home brewers:

The Kalita 185 filters yield a partial-bypass, stratified, high-clarity profile akin to other flat bottom brewers like the Kalita and Orea.
Using the AeroPress XL & Sibarist DISC 72 filters along with low agitation, yields a no-bypass, high extraction profile very similar to brewers like the Pulsar and the new Orea Z1.

Using the Melodrip as a shower head to achieve ultra-low agitation brews offers unprecedented levels of control and consistency.
Brewing a dark roast ristretto-style drink and pouring that onto a scoop of vanilla ice cream, creates the equivalent of an affogato, a popular summer drink. Our customers have been calling it the SOFI-gato.
Iced SOFIs have very similar characteristics to cold brew coffee, a drink that is exponentially growing in popularity. However, SOFI brews do not have the same long wait time, unpleasant effects of oxidation, and hygiene issues.

Image 6. Using Kalita filters and a Melodrip as a showerhead on top of SOFI

SOFI is one way to make specialty coffee more inclusive. For example, a coffee that highlights acidity when brewed with a V60 or a Kalita may be more enjoyable to someone when brewed with SOFI, which mellows and rounds out acidity. By doing so, you have essentially expanded the potential audience for a given coffee.

It has truly confounded us that this extremely versatile brewer has been sitting in plain sight for so long. Currently, with the rise in popularity of no-bypass brewers on the market (Orea Z1 and Pulsar), Indians have to import these plastic no-bypass brewers at ~2x the cost of SOFI. Whilst Indians have had access to the South Indian Filter all along, it has never been associated with or thought of as being a no-bypass brewer because of the narrow lens through which it has traditionally been viewed. Shining a light on all its capabilities through SOFI is what has helped achieve broader, global appeal.

4. Relevance of Knowledge Sharing

Much like food, coffee has grown in popularity as a drink around which communities are formed. Previously restricted to homes and social interactions with friends and family, knowledge sharing now transcends borders, languages and cultures. Millennials and Gen Z especially see real value in bonding over food and drink.

However, in order to share knowledge, measurements and recipes like those used in food, are needed for coffee too. Being able to compare apples with apples requires a certain amount of standardisation to maximise what we get out of different brewers and coffees. Troubleshooting becomes easier, making the process of experimenting a more robust one, and this forms the basis for being able to study the science behind a brew.

VI. CONCLUSION

Our ethos at Aramse is to design products for social connection, and SOFI is one example of how we want to create communities around a brewer that adds delight to your day. We use SOFI as a lens for how we think about Indian objects and their importance if we want to cement our place on the global stage as thought leaders.

Image 7. SIF/SOFI talk at the Indian International Coffee Festival

Zooming out and looking at the bigger picture — the dynamics in coffee desperately need to change with the onslaught of ever-rising crises. The biggest consumers, countries in the proverbial Global North, have always used producing countries in the Global South as suppliers of raw material. Beyond that, we have all grown accustomed to the Global North assuming control of thought leadership — right from defining quality standards in coffee to shaping sustainability solutions, and beyond. This means, real value creation, especially monetarily, in coffee has been ring-fenced by these countries. For coffee to become more sustainable and equitable going forward, producing countries should be included in a wide gamut of conversations such as sustainability, growing and processing, sensory analysis, or brewing methods. Technical insights, from scientific research and design inspiration should come from the Global South too.

Producing countries are often resource constrained, forcing them to come up with creative solutions to rather complex problems. In India, we see this every day across industries — a concept popularly known as jugaad, and a superpower in an increasingly uncertain world. Tapping into this knowledge base gives producing countries access to the higher end of the value chain, and also makes the overall pie larger, possibly increasing revenue streams not discovered before.

In his paper Quality and Inequality: Creating Value Worlds with Third Wave Coffee, anthropology professor Ted Fischer writes about distinct value worlds referring to the disparity that exists between the value created at origin and value created at the consumer end. We generate monetary value out of ‘quality’. But what is quality? He astutely highlights “the underlying truth that quality is not discovered, but created.” While this was written in the context of raw coffee we think this is relevant for the coffee industry at large. Including producing countries in the narrative means you have different perspectives generating richer ideas. We will likely arrive at solutions quicker or find that they already exist, and most importantly we start to bring these value worlds closer together.

We are using SOFI as one example of a producing country creating quality, and therefore value by modernizing a hidden treasure that was ahead of its time.

VI. ADDITIONAL RESOURCES

VI. ACKNOWLEDGEMENTS

A special thanks to the Coffee Board of India and Dr. Ramya Mohan for their encouragement to publish a white paper on our rationale for developing SOFI. We appreciate the time taken to vet it and help us deliver the most straightforward version of the paper.

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