A barrel of raw ale, Vilnius, Lithuania

The topic for the session #100 is "resurrecting lost beer styles". I decided to choose what is very likely the biggest beer style you've never heard of: raw ale. It's not even a single style, but a whole group of beer styles, all of which share one characteristic: the wort is never boiled. Strictly speaking raw ale neither dead nor lost, but it's still in need of a ressurection. Because even though these beers are spread over a wide area, and historically have been extremely important, hardly anyone has ever heard of them.

To my mind, raw ale is important because it tastes very different from boiled beer, and because the best raw ales can be absolutely amazing. Examples: Hornindal, Jovaru Alus, Storli Gard. So it's clear that there's rich ground here for anyone wanting to brew beer that's interesting and different. In addition, there is the historic importance, which we will return to.

In fact, the difference between raw and boiled beer is so stark that the tree of beer styles should probably look like this:

Beer style hierarchy redrawn

Unfortunately, that's going to break some well-known styles in two parts (sahti, for example), because the style as currently described includes both boiled and raw ales. To my mind that's not a problem, because raw and boiled sahti are vastly more different than, say, IPA and pale ale are.

"You have to boil the wort!"

Now, as any homebrewing manual will tell you, a fixed and key part of the brewing process is boiling the wort. It's such a key step that the brewing process is often divided into "the hot side" (before boiling) and "the cold side" (after boiling). Weirdly, a number of texts on the history and archaeology of beer also assume that beer must necessarily be boiled.

Boiling is important because it achieves (at least) three things:

Sterilizing the wort, thus avoiding infection.

Isomerizing the acids in the hops, adding the bitter flavour, and further protecting against infection.

Removing protein from the beer, which improves flavour stability.

However, as it turns out, most farmhouse brewers today don't actually boil the wort. Nor did their ancestors. And while this may sound like a relic of the Stone Age (which in some ways it is), some of them actually make magnificent beers which can compete with any boiled beer. But what about the three issues above, then? Let's do them one by one:

Mashing effectively pasteurizes the wort. Keeping the wort at 63C for 30 minutes is generally considered sufficient for pasteurization, and farmhouse brewers mash for from 1 to 24 hours.

Isomerization of the hops is solved in various ways. Some boil hop tea in water on the side, then pour that in. Others take off a little of the wort, then boil it with hops, then pour that in. Some pour near-boiling wort on the hops. And some drop it altogether. Turns out it's not absolutely required.

The protein never does get removed. That seems to be at least part of why many of these beers have poor stability.

In other words: what brewing literature teaches us is an absolute requirement is actually unnecessary. And what historians and archaeologists tend to assume was a fixed feature of prehistoric beer is still, to this day, not part of the brewing process for traditional brewers in large parts of northern Europe.

Brewing raw ale, unsuccessfully, Oslo

Defining raw ale

Strange as it might sound, raw ale is a fuzzy concept, because there's no sharp line dividing raw ale from boiled ale. Sometimes people boil only 1/6th of the wort. Is it then raw ale? Normal beer is boiled for at least an hour, but farmhouse ale can be boiled for 2 minutes. Is it then really boiled ale?

For the drinker, what matters the most is the flavour, so I tend to use the yardstick that if the process makes it taste like boiled beer I'll consider it boiled beer. Thus, if most of the wort is raw, or the boil is so short that the hops don't isomerize and there's no hot break releasing the protein then it's a raw ale. Unfortunately, I have no emperical evidence for where the dividing line lies, so for now let's say a boil shorter than 30 minutes gives you a technically raw ale.

Having said that, the majority of people making raw ale don't boil at all. In fact, a number of farmhouse brewers consider that boiling the wort will spoil the beer.

Range today

Of the farmhouse ale brewed today, how much is raw ale? That's nearly impossible to quantify with anything like precision, but I can outline the areas where raw ale appears to be the norm:

Norway: large parts of Sogn og Fjordane, Sunnmøre, and Oppdal, and to some degree also Stjørdalen. [Own research]

Gotland: most of the beer appears to be boiled, but boil times vary from 1-2 minutes to hours. [Salomonsson 1979]

Finland: most sahti is unboiled. [Ovell 1996]

Estonia: I don't know of any boiled koduõlu. [Järmälä 1997]

Latvia: the beers in Latgale seem to be unboiled; not sure about western Latvia yet. Older literature describes mostly raw ale. (Sources: Cinitis and [Hupel 1777].)

Lithuania: I don't know of any boiled traditional farmhouse ale. (Sources too many to list, but see Gutautas.)

Mug of raw ale

In the recent past

If we roll back a century or so we can add to the list above:

Denmark: My research is not complete, but so far all Danish farmhouse ale appears to have been raw ale. That's what's described in older literature, and in all the survey responses I've read so far. [Olufsen 1812] [NEU]

Germany, Switzerland, Austria: there are lots of hints and whispers that at least some of the farmhouse ales in these areas was raw ale, but so far the documentation is missing.

Russia: Some of the farmhouse ales made by Russian minorities were raw ales, but not all. Russian farmhouse ale appears to have been at least mostly boiled. [Räsänen 1975]

UK: The farmhouse ale brewed in Orkney in the late 19th and early 20th centuries was tantalizingly close to raw ale. [Scott 1967] describes boiling for two hours, but [Firth 1920] gives the boil time as half an hour. (Many thanks to Merryn and Graham Dineley for sending me these.)

Very likely the list should contain more, but more research is needed.

Further into the past

Now, as I've documented above, most farmhouse ale today and in the recent past was raw ale. As we go further back, some important technology disappears. Without a metal kettle, boiling becomes difficult. Copper kettles have been around for more than two millennia, but until the last couple of centuries they were very expensive high-status items. As odd as it might sound now, in the Iron Age a copper kettle would make a good gift for a chieftain, for example.

Exact valuations are rare, but in 1350 the heirs of Eirik Bukk at the Finne farm in Voss, Norway, divided their inheritance. The document has survived, and values his three copper kettles at eight cows. [DN I 321] This at a time when a manorial farm might have 12 cows all told, and a small farmer might have just one. In other words: copper kettles were seriously expensive items. Accounts from continental Europe agree, for example, [Unger 2007] says that in this period the copper kettle was undoubtedly the most expensive equipment the brewer had.

Hence, people would brew in wooden vessels, and heat the liquid with stones. As some people still do. It's possible to boil wort for an hour with stones, but it's hard, and it takes a lot of fuel. We've already seen that raw ale was very likely extremely widespread a couple of centuries ago, and in the stone boiling era it likely dominated totally.

Medieval drinking horn (1950s replica), Vest-Telemark Museum

Another change that's important here is the introduction of hops. Before the introduction of hops beer kept poorly anyway, so the sterilization and protein issues didn't matter so much, and the hop isomerization obviously did not apply, either. It follows that before hops were introduced there was really no reason to boil the beer at all. Add to this the difficulties of boiling with stones plus the cost of fuel and it becomes very unlikely that unhopped farmhouse ale was boiled. Further, boiling removes protein from the beer, which reduces the nutritional value of it.

Indeed, there is every possibility that unhopped commercial beer wasn't boiled, either. Several English sources from around the time that hopped beer was introduced (16th-17th century) indicate that even unhopped commercial ale was unboiled. [Holme 1688] [Harrison 1577] In the Low Countries, it seems that around the time that hopped beer replaced the older gruit beer (14th century), copper kettles also became much more common (12th/13th century), which is interesting. It may well be that this is when breweries in the Low Countries started boiling their wort. [Unger 2007]

Conclusion

In short, raw ale is a major branch of the tree of beer styles, and so far unjustly ignored. Most farmhouse ale is raw ale, and historically the dominance has been even greater. Very likely just about all prehistoric beer was raw ale. Which again means that probably every single modern recreation of ancient ales has missed a key point: don't boil the wort.

The main difficulty with commercial production of raw ale is very likely going to be shelf-life. There are, however, people who have been and are able to brew raw ale that lasts at least some months, so this need not be unsolvable.

Sources

DN I 321 Diplomatarium Norvegicum, volume 1, letter no 321.

Firth 1920 Reminiscences of an Orkney Parish, John Firth, W.R. Rendall, Stromness, 1920.

Harrison 1577 A Description of Elizabethan England, William Harrison, 1577.

Holme 1688 The Academie of Armorie, Randle Holme, Chester, 1688.

Hupel 1777 Topographische Nachrichten von Lief- und Esthland II, A. W. Hupel, Riga, 1777.

Järmälä 1997 Estonian Koduolu - Homebrewing in Estonia, Ari Järmälä, web page, 1997.

NEU Nationalmuseets Etnologiske Undersøgelser, Danish National Museum.

Olufsen 1812 Anviisning for land-almuen til at brygge øl, C. Olufsen, Copenhagen, 1812.

Ovell 1996 Finland's Indigenous Beer Culture Peter Ovell, Perinteisen Oluen Seura, Special Publications No 1, Helsinki, 1996.

Räsänen 1975 Vom Halm zum Fass, Matti Räsänen, Kansatieteellinen arkisto, Helsinki, 1975. ISBN 9519056181.

Salomonsson 1979 Gotlandsdricka, Anders Salomonsson, Lund, 1979.

Scott 1967 Island Saga: The Story of North Ronaldsay, Mary A. Scott, Alex Reid & Son, 1967.

Unger 2007 Beer in the Middle Ages and the Renaissance, Richard W. Unger, University of Pennsylvania Press, 2007. ISBN 978-0-8122-1999-9