What is Sool?

Hanja for sool
Hanja for Joo/Sool which in itself resembles a bottle.

The Sool Company takes its name from the word in Korean which refers to alcohol. Like many of the traditional expressions which refer to recipes, techniques and styles of Korean alcohol, there are some variations on its meaning and interpretation. This article hopes to clarify the meaning of the word Sool, for those new to the world of Korean fermentation.

In modern Korean, the word Sool is used to refer to all types of alcohol. Including makgeolli, soju, beer, wine and whisky.  There is no differentiation between domestic and imported alcohols in terms of its use. However, it has a meaning that is tied to the history of the production of fermented alcohols of Korea.

As is true internationally, the history of fermentation in Korea predates an understanding of the biological and chemical processes that the raw ingredients undergo. Therefore, a lot of the terminology and nomenclature used to describe processes or reactions that are invisible or inexplicable to a layperson, either just explain visual phenomena or have a spiritual quality.  This is true of the historical brewers from the Joseon dynasty.

Brewing in Korean History

Brewing was commonplace before the Joseon period of Korea (Founded in 1392). However, it flourished heavily due to Royal restrictions on brewing and the subsequent surge in illegal homebrewing that followed. Most of our traditional recipes and terminology used for describing Korean brewing techniques, processes and measurements come from this period.

Nowadays we have an understanding of the alcohol fermentation process. In its simplest form, it is the conversion of sugars into ethanol, predominantly with a Saccharomyces yeast being the instigator of the change. Through that microorganism’s consumption and breakdown of sugar molecules into ethanol, we get other chemical byproducts and the production of heat.

One of these byproducts is key to our understanding of the word Sool and its origin in the perception of fermentation by Joseon dynasty brewers. Carbon dioxide (CO2) is the most recognizable chemical product of a yeast driven alcohol fermentation process as it takes the form of vigorous and visible bubbling. It is not dissimilar to the effect of boiling a liquid.

The Origins of The Word ‘Sool’

Without a knowledge of chemistry or biology, the association of heat and boiling when observing the CO2 output of yeast would be a natural one to make which is why brewers in the 15th century referred to brewing with terms relating to fire.

Hanja Character for Water.
Hanja Character for Fire

[quote align=”left”]In Korean the word for water is mul/mool (물), however the Chinese expression su/soo (수) was and is still heavily used. The Korean word for fire is bul/bool (불).[/quote]

When observing the effervescence of fermentation Joseon brewers understood that they had used their brewing technique to unlock some elemental fire that was contained within their water. They created boiling without the use of external heat. They used the expression soobool (수불) to refer to this.

Most homebrewers and families communicated their culture, stories and recipes in the oral tradition, so there are very few early Joseon records of brewing practices. However, there is a record from 1446 referring to soo-ul (수을) (1) which is a contraction of Soo and Bool. Fire & Water.

The Modern Use of The Word ‘Sool’

This word persisted over the centuries but found itself subject to further contraction. Finally evolving into the single syllable of sool (술).

The etymology and the historical usage of the word ‘Sool’ are bound to the mixture of grain, nuruk & water, and reflects the brewer’s understanding of the processes in play during the fermentation process that followed. Recently, terms have become popular, even standard which delineate this alcohol based on other criteria. Jeontongju (전통주) translates to  Korean Traditional Alcohol (2). Minseok Ju (민속주) translates to Folk Alcohol whereas another common term is Woorisool (우리술), meaning ‘Our Alcohol’, with the ‘our’ meaning Korean.

These expressions are only the most common among a large number of alternatives and variations of descriptions of alcohol that has a Korean heritage. None of these are particularly comfortable when translated and used frequently in English. The word Sool has its roots in the traditional Korean fermentation style and is distinct and simple enough to pronounce by English speakers. Hence our motivation to choose this term for the promotion of Korean alcohol internationally, much in the same way Japanese alcohol is branded as ‘Sake’ to global markets, as well as why we designated it as the keyword in our company’s name.

We hope this article clears up at least one expression you may come across in our material.

For a deeper understanding of the basics of sool making, you can check out our free Makgeolli Homebrewing Crash Course where you will learn everything you need to know to make your own sool.

Brewing In Tight Spaces, Godubap on the Go

Godubap on the go

We are truly spoiled at times here at The Sool Company, particularly when it comes down to brewing and the facilities we use. Thanks to our regular brewing classes, we have access to several locations here in Seoul where we are able to use large-scale steamers, wide open workspaces for cooling and mixing, stainless steel bowls and fermenters, science things for science-ing what we make, and anything else we can think of to make brewing standard and obscure recipes possible.

Dan during a distilling class

We also like to brew a lot, whether it’s for ourselves, friends, events or for our regular brewing classes, so having a bigger workspace in order to make rice cakes, porridges or even to lay out our rice to cool is something we are very grateful for.  That doesn’t mean that we don’t brew big at home. Last month, I bought and started using a 30-litre clay pot for brewing into that has presented some new challenges to my homebrewing set-up, but more on that later.

Recently, however, we have been branching out and brewing in newer locations that are not set up for brewing purposes. For example, in November we hosted a special one off brewing class in Chungmuro at the beautiful Yesultong art space. One of a few spots in which we intend to run brewing programs for visitors during the Pyeongchang Winter Olympics in 2018.

The room we were hosting in was gorgeous, with a fantastic screen, a large meeting table and ornate petrified wooden chairs. A great space to drink and talk about brews and the finer things in life, but completely lacks any of the equipment that we normally use for brewing. We needed a creative solution to make sure our rice could be prepared for brewing, and I thought it would be a good thing to share with all of you.

Steaming large amounts of rice can be quite tough, especially in a confined kitchen or with a small dumpling or vegetable steamer. The process takes some time, and I’ve personally had to steam my godubap in several batches. Meaning I was beholden to my steamer for hours, while I steamed one batch while one was cooling and another sat drip drying.


If you are aiming for consistency, then this is not an ideal situation, as your earlier batches will end up drier and the starches will start to retrograde, causing incomplete fermentation and some rough flavors.

Most Korean neighborhoods are very likely to have a Deok Jib (떡집), a rice cake store, where various starchy rice cakes like Beksulgi (백설기) and  Songpyeon (송편) are produced. If one who is familiar with brewing and rice prep looks inside you will notice that their equipment, particularly the steamers and grinders are pretty much identical to the ones that we use for producing godubap or grinding mepssal (short grain rice).

The only difference practically between the way the rice is prepped for brewing and making rice cakes, are the addition of salt and sugar for the latter use. So make sure to say that you are using your rice for brewing and that you don’t want anything added (although a salty brew does sound kinda yummy…)





Most rice cake stores here are happy to produce your steamed godubab with chapssal or mepssal for your brew, as well as to grind up any rice you might want to use for making your own primary fermentation stages too.You can pick up the goods directly, or in some cases they will deliver (and at a set time If ordering well in advance) This solved our issue of brewing in a space where we were unable to steam or grind and it can also deal with the problem of steaming in a tiny Korean house kitchen.


So far we have successfully managed to have our piping hot steamed rice delivered in a couple of locations in Seoul, as well as in Gapyeong during the makgeolli festival and… surprisingly…. in Sydney Australia where we found a Korean rice cake store as well.

So, search out your local Ddeokjip (떡집) when in need or feeling lazy ~ and get your brew on!

End of brewing class group photo


That’s a Lot of Lotus!

Over the last month, The Sool Company has been running a series of brewing projects with some fellow alcohol enthusiasts, and we have been brewing up a storm. One of the projects we have been working on is a lotus leaf brew.

Continue reading “That’s a Lot of Lotus!”

Fantastic Berries & Where to Find Them

Producing any specialty type of food or alcohol generally requires specific equipment and ingredients to be successful. Sometimes sourcing these weird and wonderful items can be a little bit tricky, however, I do have my own favourite spot for procuring exotic Korean materials.

Continue reading “Fantastic Berries & Where to Find Them”

Adventures And Misadventures in Homebrewing

The gurgling, wheezing and squealing had continued for several hours. I laid awake trying to ignore those pitiful, desperate pleas coming from a dark corner of the room, but to no avail. Then, just as the sun came up when I had given up all hope of getting any sleep, came the bang…

…and then silence.

Continue reading “Adventures And Misadventures in Homebrewing”