As every brewer knows, you have to boil the wort. Except that’s not true at all. In much of northern Europe, farmhouse brewers never boiled their wort, and many of them still don’t. People brew raw ale today in Norway, Sweden, Denmark, Finland, Estonia, Latvia, Lithuania, Belarus, and Russia. And, no, they don’t make sour beer. I guess that sounds weird, so let me explain.

In the Middle Ages and before, metal kettles were extremely expensive. So expensive that, for most people, owning one was just not going to happen. They had to brew their beer without a convenient container to heat water in. Many solved it by mixing water and malts, then dumping stones heated in a fire into the mix to bring it up to mash temperature (similar to how German steinbier is made). Afterwards, the brewer would lauter, cool the wort, and pitch the yeast.

Boiling? There is no need for it.

I know this sounds incredible, but people have been brewing raw ale for many centuries. They know perfectly well that other people boil the wort, but they see no need to change what works well for them. And if they boiled the wort they’d suddenly be brewing a different style of beer.

Of course, as metal kettles became affordable, most people started using them, but in different ways. People started boiling the wort in some places, while in other places they just heated water to pour on the mash (eliminating the step of heating stones in the fire), and never bothered with the boiling. And some found even more creative solutions.

Using hot stones became quite rare by the 18th century, but the use persisted in some remote regions, and even today there are people brewing with hot stones in the mash. They have metal kettles, but they like the flavor added by the stones.

The brewers were often aware of these regional differences, and in some places it became part of the local identity. In western Norway, the people of Sogn were aware that to the north people were not boiling the wort. This was considered barbarous, and the result undrinkable. Their northern neighbors saw it differently. These people boiling the wort? They were “again-boilers,” people with such poor control of hygiene that they had to not just boil the brew water, but also the wort.

I have countless descriptions of how raw ale was brewed from archives and old books, but you can’t really understand a beer unless you’ve tasted it. And these old descriptions usually don’t mention temperatures, or precise amounts of ingredients. So to really get to the bottom of these old brewing methods I have traveled to talk with traditional farmhouse brewers, taste their beers, and brew with them.

In the summer of 2016 I visited Paavo Pruul, near the south tip of the Estonian island of Hiiumaa in the Baltic. Paavo learned to brew from his grandfather, the way real farmhouse brewers do. He brews koduõlu, the Estonian cousin of the Finnish sahti. His grandfather malted his own grain, but Paavo has chosen to buy instead. The entire grist is Weyermann Vienna.

Paavo brews outdoors, using a bricked-in kettle on the porch of his guesthouse, plus some wooden vessels he inherited from his grandpa. He starts by heating water in the kettle. His grandpa used to put juniper branches in the kettle to make a juniper infusion, but Paavo says many people think the juniper flavor gets too strong, so he doesn’t use juniper in all the brewing liquor.

Once the water is hot he pours it into a big wooden vessel that looks like a barrel with no lid. Then the malts are poured in while stirring with a wooden pole. Once it’s all done the temperature is 160 °F (71 °C). Paavo then wraps the mash tun with clothes to add a layer of insulation. Grandpa used to add hot stones to the mash, but with the bricked-in fireplace that’s awkward, so Paavo skips that.

Meanwhile, we go off to the forest to pick juniper (Juniperus communis), which grows everywhere on Hiiumaa as huge, dense bushes. The juniper is laid in the lauter tun. It stands on a wooden stool, above a wooden trough, and has a hole in the bottom, through which the wort will run into the trough. The hole is closed with a wooden pole that’s tapered at the end, so that by pulling it up slightly you can regulate the flow of wort. The exact same equipment, apart from the trough, can be seen in museums all over Denmark and Sweden, and it’s still in use in parts of Latvia and Lithuania.

The juniper is tied to the pole, making it look like a broom, and also laid on the bottom (shown in the picture at the top of the page). Paavo wedges a stick that’s exactly the right length against the sides of the vessel to hold the juniper down. The juniper will act as the filter during lautering, and add bitterness and aroma at the same time.

While waiting, we drive to grandpa’s farm where hops are growing against a fence in one side of the garden. The fence is maybe 30 to 50 feet (10 to 15 m) long and completely hidden by the hops. They were planted by grandpa, says Paavo. It’s local farmhouse hops, grown here on Hiiumaa since forever, so the variety has no name. I tell him it’s great that he’s taking the trouble to maintain this old variety, but Paavo just looks at me. “We pull down some plants now and then so they don’t take over the garden, but other than that there’s nothing to do.” It would actually be more trouble to get rid of the hops than to keep them.

When the first water had been added to the mash, Paavo put more water in the kettle, then added hops to it. He’s basically boiling the hops in water, then adding that to the mash. He’s also picked Myrica gale on the beach and adds a bunch of that. His grandpa didn’t use it, but it’s an old tradition on the island, and Paavo likes the lime-like woody flavor. After about an hour this water was also added to the mash. The kettle was filled with water again, and some juniper branches were added to make a juniper infusion for the lautering.

Finally, after four hours, the mashing was finished. The temperature had now come down to 153 °F (67 °C). Paavo scooped the mash out of the mash tun and over to the lauter tun. The juniper infusion had boiled for an hour and a half and turned brown, roughly the color of Earl Grey tea. While boiling hot, this was used to clean the mash tun, and then poured into the lauter tun. The mash tun doubles as a fermenter, so it has to be clean. The former mash tun, now fermenter, was carried into the house and put in a storage room.

Paavo now lifted the rod slightly, and milky pale brown wort started running into the trough. Once enough wort had collected, it was scooped into milk cans. Once a can was full, it was lowered into the well to cool, then carried into the house and poured into the fermenter.

Yep. No boil.

A little cold wort was poured into a bucket, and yeast from a glass jar, kept in the fridge from the previous brew, was added. This is Fermentis S-04, but in older times the brewer would have had his own yeast. Paavo brings out a mortar and pestle and crushes some blackcurrant leaves, then drops those in the yeast starter. I ask him why, and Paavo just smiles and says “I learned this from grandpa, but I don’t know if it’s theoretically right.” That’s the essence of farmhouse brewing right there. There is no theory, no chemistry, and no biology. You just repeat what your predecessors did, because the method has been perfected over many centuries, and you know it will work. But you don’t know why it works. It just does.

Once all the wort is collected in the fermenter and the starter has begun bubbling, it’s time to add it. Paavo pours it in, and says his grandpa taught him that at this point he must say the names of all the angry dogs in the village. If he leaves out one the beer won’t ferment. “But you didn’t actually say it,” I point out. Paavo just laughs and says: “It’s enough if I say it in my head.”

Three days later the beer will be finished fermenting and ready to drink. And then grandpa’s neighbor would come by, asking to borrow the ladder that was longer than his own. Since the beer was just then being transferred to keg he would of course be asked to taste it, and a small party would develop in the brewhouse. The neighbor did this with every brew for 40 years.

The finished beer is lovely, with a delicate fruity aroma blending the blackcurrant leaves, juniper, and myrica. Behind that you can make out the strawy, grainy flavor of the malts, together with the peculiar “green” flavors of the raw ale. There isn’t much sign of the hops, but the aftertaste is pleasantly dry from the juniper and the hops, balancing the initial sweetness perfectly. No sign of acidity, or any kind of funk.

But Isn’t Boiling Necessary?

But how can this actually work? Let’s look at what the textbooks say about boiling the wort. There are three main reasons the boil is stressed as being critical.

First, we boil the wort to sterilize it. But if you keep your mash at 153 °F (67 °C) for an hour, you have basically pasteurized it. A temperature of 145 °F (63 °C) for 30 minutes, or 162 °F (72 °C) for 15 seconds is considered enough for milk products. (Note: These guidelines are for removing pathogens, and not spoilers like lactic acid bacteria. Milk is also easier to pasteurize than a mash with malt lumps in it. So beware these guidelines are not enough to prevent your beer from souring.) Paavo had the mash at 153 °F (67 °C) and above for four hours. While this wort isn’t sterile, neither is a boiled wort that you as a homebrewer chill in an open kettle in your kitchen before pouring into the fermenter. But it’s close enough that the yeast and the hops take care of the rest.

Which brings us to the second point: You have to boil the hops to isomerize the alpha acids in them. Typically for farmhouse brewers, the solution is brilliantly simple. Just boil the hops in some water to make what’s called “hop tea.” That saves massive amounts of time and energy. Or, do like the Norwegians, and boil “humlebeit,” where you boil the hops in a little of the first runnings. Or, just run the hot wort through the hops and skip the boil. Other substances in the hops, besides the alpha acids, also protect against infection.

Finally, boiling the wort makes a whole range of other reactions happen, too. For example, it makes proteins coagulate, so they drop out of the beer. In raw ale, this doesn’t happen. That, it turns out, isn’t actually a problem. It just means that raw ale gets a recognizably different flavor profile from boiled beer.

Apart from the difference in the flavor, farmhouse brewers are mostly unaware of all this. Farmhouse brewers don’t learn brewing by reading textbooks or taking courses. They learn from their parents, or their neighbors. And what they learn is not the theory of brewing, but how to brew a specific beer. Do this, then do that, check the taste of this, and so on. What they’ve learned works fine, even if nobody ever tells them why it works.

So How Does Raw Ale Taste?

For one thing, it has more protein, so it tends to be fuller-bodied even when highly attenuated. There are also some characteristic “green” flavors that are hard to describe. Basic grain- and straw-like flavors from the malts tend to come through much more clearly in raw ales. Once you’ve learned to recognize them, the flavors aren’t that hard to pick out, as long as there isn’t something else in the beer (such as hops) overwhelming them. You may be wondering if Dimethyl Sulfide (DMS) would be an issue however, with temperatures typically never exceeding 185 °F (85 °C) S-Methyl Methionine (SMM) converts to DMS very slowly. DMS is volatile above 122 °F (50 °C), so what little there is will tend to evaporate during the long mashes and sparges. The warmer/quicker fermentation will likely scrub out the remaining DMS.

Before you start searching for raw ale recipes, you need to realize that this is not a style. Just like boiled beer isn’t a style. Not boiling the wort is normal for sahti, pretty common in gotlandsdricke, and used to be normal for Berliner weisse. It was also common in many, many dead farmhouse ales.

Even today it’s normal for koduõlu. In the northern part of western Norway, the brewers make kornøl, which is also a raw ale style. In northern Lithuania, people brew kaimiškas, yet another raw farmhouse ale.

It might seem incredible, but there are breweries making raw ale commercially. I visited Piniavos Alutis, a small farmhouse brewery in northern Lithuania. I’d been a fan of their oddball beers for years. The beer they’re most known for, even if it’s not their best, is Laukinių Aviečių, a dark farmhouse ale with raspberry canes. It really is the canes, or shoots, which is very unusual.

The brewery is located in what used to be the barn on the farm, but that’s not what makes it a farmhouse brewery in my eyes. It’s a farmhouse brewery because it brews entirely within the farmhouse tradition. The brewer, Vidmantas Perevičiaus, learned to brew from his mother’s uncle, and still brews in the family tradition. His family comes from the Kupiškis area, and when I asked him why he doesn’t then make keptinis, the farmhouse style Kupiškis is famous for, he said it’s because his family is from the northwestern part of that area.

He took me to see his brewery, which at first glance looks like most small craft breweries. Two big steel tanks in the brewing room, with a steel platform in front of them, then lots of steel fermenters in the next room. The steel tank on the right was the mash tun, the one on the left the lautering tun.

“So,” I asked, “no copper, huh? This really is a raw ale brewery?”

“Of course,” was the answer. “We make Lithuanian farmhouse ale.”

That didn’t really surprise me. I’d tasted the beer, and by then I knew this was a very traditional brewery.

“That small tank in the corner, what’s that?” I asked.

“That’s the hop tea cooker.”

However normal it might look, this wasn’t an off-the-shelf brewkit. Which led me to my next question.

“You didn’t buy this brewery, right? Where did you get it?”

“We made the drawings. Local masters came here and welded everything.”

That’s when the flash went off in my head. In farmhouse brewing the mash is usually filtered the way Paavo did, but many people used straw instead of juniper. That had to be what the raspberry canes were for! And, sure enough, it turned out that most people in the area had used straw for the filter, but in the Perevičiaus family it was tradition to filter through raspberry canes. So that beer was a tribute to the family tradition.

Note how everything about the beer comes from local and family traditions, down to the physical design of the brewery itself.

I saw something very similar when I visited the Pihtla Brewery on Saaremaa island in Estonia. They make koduõlu in a brewery they built from parts scavenged from a Soviet-era soap factory. Just as with Piniavos, there was no boil kettle. The wort was hosed directly from the mash tun to the fermenter, and hop tea, boiled on a normal kitchen stove, was added.

A couple of years ago the brewer took on a younger partner, who wanted to add modern craft beer to their lineup. The problem with that was that there was no kettle to boil the wort in. They solved this by transferring the wort from the mash tun to the water heater (for the mash water), then hosing it back into the fermenter. That seems to have worked, because their porter is a perfectly fine porter. Although if you do ever visit Estonia, of course you should have their koduõlu, called Pihtla õlu, instead.

Raw Ale in the Homebrewery

So how can you as a brewer make use of this technique? There are two main ways. One is to just steal the idea and use it either in established styles, or to innovate. The other is to brew a raw ale style (such as the two recipes at the end of this story). If you concoct your own recipe you run the risk of producing something that’s not very good because you’re playing with flavors you’ve never tasted. With an existing style that’s less of a risk. Either way, the benefits are saving time and energy, and producing new flavors that few people have tried before.

One style that can benefit from incorporating the raw ale technique is New England IPA. This style is supposed to have a soft and juicy mouthfeel, and not boiling the wort contributes to that through the protein that helps fill out and smoothen the body. The effect is not too different from using oats or wheat in the grist. The relatively subtle raw ale flavor, however, will be overwhelmed by the hops.

Another style that can benefit from not being boiled is saison. In a dry saison with European aroma hops the protein will fill out the body nicely, and the grainy, green flavors from the raw wort will blend in nicely with the slightly funky saison yeast aroma.

A more difficult style to brew is kornøl, because it has a unique brewing process and requires juniper branches and kveik yeast, both of which can be hard to get a hold of (however kveik yeast strains have become more common on the market in recent years). Koduõlu is a little easier, because one can use baking yeast instead. Or, failing that, a really aromatic hefeweizen yeast at high temperature.

And so we have, in a sense, come full circle. The raw ale brewers used techniques derided as old-fashioned and wrong-headed by other locals who have learned modern brewing techniques. Now, people are beginning to realize that actually, they have done us all an invaluable service, by keeping alive knowledge of techniques that all brewers can make use of. It’s high time that these brewers get some credit for what they have done.

Paavo Pruul’s koduõlu (western Estonian farmhouse ale)

(5 gallons/19 L, all-grain)

OG = 1.066 FG = 1.016

IBU = ~14 SRM = 8 ABV = 6.6%

I’ve had to extrapolate some of the numbers and ingredients from other brewers on Hiiumaa and Saaremaa, since Paavo never weighed his hops or measured the alpha acids in them. The malts really should be homemade, and most brewers use Estonian bread yeast, but obviously that’s not going to work here. The juniper must be Juniperus communis, branches, not too thick, with some green or blue berries on them.

Ingredients

14 lbs. (6.4 kg) Vienna malt

1–2 blackcurrant leaves (not necessary)

3–4 juniper branches

5–6 stalks of sweet gale (60 min.)

19.6 AAU Saaz hops (60 min.) (7 oz./200 g at 2.8% alpha acids)

Fermentis S-04 or a hefeweizen yeast

Step by Step

First, remember that you are making a farmhouse ale. You don’t have to hit any of the numbers exactly. A day or two before brew day, make a 1-quart (1-L) yeast starter with (optional) crushed blackcurrant leaves mixed in.

On brew day, mill the grains, then put 2–3 juniper branches in the bottom of the mash tun and the malts above them. Add hot water, about 3–3.5 gallons (11.4–13.3 L) to hit a mash temperature of 160 °F (71 °C), and stir well. This should be a very thick mash at this point (where a heavy wooden mash paddle will slowly tilt to the side). Make sure the mash tun is well insulated so the temperature stays high. Leave for two hours. After the first hour, bring about 1 gallon (4 L) of water to a boil with hops and sweet gale in it and boil for one hour. Add the boiling hop- and sweet gale-infused water addition, bringing the mash back up to 160 °F (71 °C), stir again, and start boiling the sparge water with a juniper branch in it. At the end, when you’ve mashed four hours, the mash temperature should be roughly 153 °F (67 °C). Finally, sparge with enough of the juniper-infused water to collect about 5.25 gallons (20 L) in the fermenter.

Pour the wort into the fermenter so it splashes against the bottom, getting lots of oxygen into the wort. Cool the wort to 68 °F (20 °C), then pitch the yeast. Let it ferment 72 hours, then transfer to keg with spunding-valve. Leave the keg in a warm place so the beer carbonates. Note that the carbonation should be well below that of modern beer.

Terje Raftevold’s kornøl (Northwest Norwegian farmhouse ale)

(5 gallons/19 L, all-grain)

OG = 1.075 FG = 1.018

IBU = 0 SRM = 5 ABV = 7.5%

Ingredients

7.7 lbs. (3.5 kg) pale malt

7.7 lbs. (3.5 kg) Pilsner malt

4.5 AAU Saaz hops (0 min.) (1.6 oz./45 g at 2.8% alpha acids)

3–4 juniper branches (the tips, with berries on, if possible)

Kveik yeast (Escarpment Labs, ideally) or bread yeast

Step by Step

Lay 2–3 juniper branches in the bottom of the mashtun, then the milled malts on top. Make a juniper infusion with the last branch, with about 8-gallons (30.3-L) water brought to a boil. Mash in with juniper infusion, targeting 165 °F (74 °C) mash temperature initially with about 5.75 gallons (21.9 L), stir well, leave it 1–1.5 hours. At the end, temperature should still be 158 °F (70 °C). Sparge by adding the remaining hot juniper infusion. Let the wort run through a bag containing the hops. Cool the wort to 86 °F (30 °C), then pitch the yeast. Ideally you should make a starter with the first wort and let the sparging go on for a few hours (Terje brews 32 gallons/120 L at a time).

If fermenting with kveik, let it ferment 48 hours. With American bread yeast, 72 hours. Store cool, in a keg with spunding-valve. By controlling the storage temperature you can control the amount of post-fermentation, which will affect sweetness and also the level of carbonation. Fermented with kveik yeast, the beer is ready to drink after 48 hours.

Tips For Success (applies to both recipes):

I realize a lot of the numbers sound absurd, but that’s really the temperatures and times these people use. I’ve brewed Terje’s recipe 3–4 times, and 165 °F (74 °C) and short fermentation really does give the best results.

During the mash, be sure to stir well so that all lumps are broken up, allowing the hot water to pasteurize the malts completely. Don’t shorten the mash, because you need the time to make sure everything is pasteurized.

Remember there is no cold-side, so you really have to sanitize the mashtun, filter, juniper branches, and everything that’s used during mash and lautering. Yes, pasteurization should, in theory, take care of it, but in practice raw ale brewers are very careful with sanitation. Terje dips the juniper branches in boiling juniper infusion, for example.