Lambic: Brewing with Bacteria
Homebrewer Wanted:
Must be willing to risk contamination of entire brewery with strange and exotic microbes from faraway lands. Must be willing to wait many years to see if the beer turned out okay. Must have a strong stomach and not be bothered by slime, scum, noxious gas, and foul odors. Must possess the patience of Job and the stick-to-itiveness of Knute Rockne. Ph.D. in microbiology a plus. Salary, none. Benefits, legendary beer — if you do all your homework — and lots of terrific stories to tell.
If this job description piques your interest, you have what it takes to make lambic-style beer, the wild beer of Belgium.
Well, it’s kind of wild in its home country. But in your brewery, things are not quite as wild. In fact to do lambic right at home, you have to get things pretty well under control. Sort of. Wild fermentation is not really a good idea at home, unless of course your home is the Payottenland outside Brussels, where the magic lambic microbes live!
Assuming your address is more domestic than that, lambic fermentation should follow a schedule and never really turn wild. Which is the reason, technically, you can’t make lambic at home. For a beer to be called lambic, it has to have been made in the Lambic region of Belgium and fermented spontaneously by resident bacteria and yeast that inhabit the nooks, crannies, and casks of traditional Belgian lambic breweries.
Make It If You Like It
If you like lambic, you have sufficient incentive to make it if for no other reason than the cost of commercial lambic. Quite a few are available in beer shops that stock unusual selections, but be prepared to pay between $10 and $20 per bottle, on average.
Another reason to make your own is that traditional, unfiltered, and strongly flavored versions of lambic are generally those that stay at home in Belgium and do not make it to US store shelves.
So, What Is This Stuff?
Lambic is a complex, unique, and unusual beer like few others. It’s fermented by no fewer than a dozen creatures, the populations of which ebb and flow in the cask as the long fermentation proceeds. More microbes may be at work but have yet to be isolated by modern laboratory techniques.
The characteristics that seem to be shared by most lambics are lactic/sour, horse, acid, and tannin/wood. Hundreds of other flavors have been detected in the brew, including esters, leather, straw, cheese, soap, mold, earth, vinegar, spice, goat, vanilla, caramel, chocolate, butterscotch, honey, sulfur, and sweat.
Now there’s a complex glass of suds!
Traditional lambic is crisp, tart, fairly dry, effervescent, and quenching. It is golden and often hazy with yeast and suspended proteins. Fruit lambics, made traditionally, are on the dry side. Unfortunately, a few of the lambics made for the US market are quite sweet and not really typical of the style.
At least one beer calls itself lambic but really is not. That’s Samuel Adams Cranberry Lambic, made by Boston Beer Co. The Sam Adams version is a well made, crisp cranberry wheat beer. However, it is not fermented spontaneously and lacks the unusual characteristics associated with the large variety of microbes that do their work in traditional lambic.
The origin of its name is clouded by centuries. Most sources trace the origin of the name to the town of Lembeek, in the heart of Lambic country.
Lambic is generally an aged style. It ages for a long time during fermentation and again in the cask. A new or young lambic is described as vos. This is encountered infrequently in Brussels cafes, where gueuze is the most popular form of unflavored lambic.
Gueuze is a blend of young and old lambics. The young lambic is not completely fermented and it is used as priming to set up conditioning in the bottle, similar to champagne or homebrew. Bottle conditioning is what gave it its name; Gueuze describes a “geyser” of beer erupting from a particularly active bottle when opened.
To pronounce it, say “gurz” or “gurza,” but don’t pronounce the “r.” Say it like you’re from Boston or New York.
A version of lambic sweetened with candy sugar is known as faro. Lambics made with fruit take on a variety of different monikers.
Students of beer know that when you drink beer, you drink living
history. This is especially so with lambic, which may be one of beer’s missing links. In his Brewers Publications book Lambic, Jean-Xavier Guinard writes that ancient Sumerian beer bears a striking resemblance to modern-day lambic formulations. The recipe was written in clay cuneiform tablets uncovered by archaeologists.
The brew, known as Sikaru, was produced 5,000 years ago from 63 percent malt and 34 percent raw wheat. Sikaru was flavored with cinnamon and other spices in the boil, then fermented spontaneously. Guinard cites the example of Cantillon’s version of lambic, which is brewed with 65 percent malt and 35 percent raw wheat and also fermented spontaneously. The main difference between modern lambic and ancient Sikaru is the spice. Lambic is made with aged hops, while hops were unknown to the ancients.
Breaking All the Rules
Lambic wort is produced by conventional means, usually through a decoction mash. Beyond that, Lambic marches to the tune of another drummer. The grist is around 65 percent malt, 35 percent raw wheat — not wheat malt.
Forget everything you know about cooking unmalted adjuncts before mashing to gelatinize the starch. Lambic wheat is not cooked before mashing, so the starches are not gelatinized. Although some lambic brewers use a decoction mash, boiling portions of the whole, other lambic brewers use a regular temperature program mash.
In either case some portion of the raw wheat starch remains unmodified. These starches contribute to the beer’s overall character and its turbid whiteness in the glass.
Forget everything you have ever read about preserving hops — freezing, storing in airtight containers, and so forth. Lambic hops are aged. They are old, oxidized, and cheesy. That’s the way the lambic brewers want them!
Brewers use aged hops because they do not want hop bitterness in the finished beer. Aged hops retain preservative properties without contributing much bitterness to the brew. Because the hops have lost their potency due to aging, hopping rates are relatively high.
Forget everything you have read about keeping your brewery clean. Lambic breweries are anything but. Dust, grime, and cobwebs are left undisturbed. Roof tiles are missing. The windows are open. And for good reason. It’s the dust suspended in the air that starts the magical fermentation of the milky wort.
The wort is pumped into a wide, shallow vessel, completely open to the brewery atmosphere. As it cools, dust and bacteria settle on the wort and contaminate it for its first fermentation, the enteric bacteria phase. The beer is racked to wooden casks shortly thereafter.
It’s no wonder the beer is so complex, since its fermentation is nothing short of Byzantine in its complexity. Amazingly enough, lambic brewers in Belgium do not inoculate their wort with much of anything. The fermentations are spontaneous, either airborne or from colonies living in the old casks in which the beer is aged.
Contamination!
Forget everything you have read about keeping bacteria out of your beer. Lambic is made possible by bacteria. Nasty ones.
The first nasties to descend on the cooling wort have been identified as varieties of bacteria related to E. coli and others known as Kloekera apiculata. They do their work for three or four weeks, after which another magic trick is performed. From nowhere, strains of Saccharomyces cerivisiae — beer yeast — take over the workload and continue to ferment the brew for up to three months. Another yeast, S. bayanus, also comes into play during this fermentation.
These somewhat conventional microbes are responsible for the main alcohol production and reduction of sugars in lambic. The rest of the colonizations occur later, after the sugar and pH levels have dropped significantly.
Take Two Penicillin and Call Me in the Morning
The next phase is the one that scares most microbiologists and food inspectors away from drinking lambic: the Pediococcus contamination. Again, the bugs that live in lambic live in few other places. Most are specially adapted to making beer. P. damnosus is the most prevalent bacteria at this stage, and lots of lactic acid is produced, which gives the beer its acidic and lactic/sour character.
By the time the Pediococci get going, the beer has become quite alcoholic and some acetobacters crop up at this stage. Believe it or not, they can make the beer go bad by turning it to vinegar. Yes, even lambic can spoil!
In Lambic Guinard explains that acetobacter is a problem throughout the process, but that the brewers know from experience that acetobacter grows aerobically — that is, it needs air, in addition to alcohol, to grow. So the casks are kept as full as possible to minimize exposure to air. In later phases a skin of muck is formed on the top of the fermenting beer, which helps to protect it against air and discourage the formation of vinegar.
You might think that all these bacteria could make you sick. Well, they could, if they were in your bloodstream or lungs. But by the time lambic is ready to drink, all the bugs have done their work and have pretty much bought the farm. Drinking lambic won’t make you sick. Even if the bacteria survive aging, they won’t survive in your digestive tract.
The hops play a key role here. Scientists such as Guinard and his colleagues have discovered that the dangerous bugs won’t grow in hopped wort, while the special bacteria indigenous to lambic are allowed to flourish.
The last fermentation occurs when the Pediococcus population is overgrown by strains of Brettanomyces, including B. Lambicus and B. bruxellenses. “Brett” is the yeast responsible for the “horsey” or “leathery” character of lambic beer. Brettanomyces work very slowly and are allowed to continue to age and ferment the beer for up to 18 months.
Plan Now for the Next Century
That’s right, 18 months. The average lambic fermentation is two years. But the hops used to brew the beer are aged for at least two years before that. So if you plan to make lambic, expect to taste it after the turn of the century!
This is a slight exaggeration. You can make lambic on an accelerated schedule. You won’t need four years, but you should plan to age the beer at least a year in the bottle. Shorter than a year and it will not be too drinkable, as homebrewer Chuck Allen of Westminster, Colo., discovered.
“My lambic was pretty disgusting for a pretty long time,” he explains. Allen’s lambic was too nasty to drink after two weeks in the bottle. After two years, it took first place in the 1996 first round American Homebrewers Association national competition in Denver.
Allen says he was intrigued with the style, though he really knew little about it at first. “I make almost exclusively Belgian styles. It was inevitable that I would eventually have to try my hand at lambic.
“I read up on it and realized very quickly that the multiple fermentations would make it a technically difficult style, so I decided to give it a try,” he recalls.
His malt bill included Belgian malt and wheat, fleshed out with Dutch extract. To keep hop bitterness low, he used only an ounce of Styrian Goldings, which he had left out at room temperature for a week before he brewed.
He fermented his lambic with a schedule of separate inoculations of Belgian Trappist ale yeast, P. damnosus (formerly known as P. cerevisiae), and Brettanomyces.
“The Trappist fermentation really went to town, dropping the gravity from 1.063 to 1.018 in just a week. It smelled great, typically Belgian and aromatic with lots of esters,” he says.
While the Trappist yeast was working, he got the Pediococcus culture going. “The Pediococcus was slow to start. I kept it at 75° F for a week to get it going. Man, was it nasty. It was stringy and slimy. Loads of milky white stuff settled to the bottom of the culture bottle,” he says. Allen usually describes this culture using words normally reserved for body fluids, such as “snot” and “phlegm.”
Allen racked the beer off the trub and pitched the Pediococcus a week after the Trappist yeast. He started the Brettanomyces culture at the same time. “I wanted a lot of brett culture, so I stepped it up once to double the volume, over two weeks. The brett was pitched last and worked for over three weeks before bottling,” he says.
He tasted it after the usual two weeks in the bottle. It was like bad beer times 10. “It had absolutely no redeeming qualities. It smelled and tasted like something that had gone really, really bad after you forgot it in the back of the fridge.
“It took courage to drink it. It smelled of decay, like something that had crawled under a rock in a swamp. The Brettanomyces character — the horsiness — was very strong. The bacteria made it nasty. It was like a rotting horse.
“I called a friend of mine, also a brewer. He listened to my description and declared it lambic,” Allen recalls.
His friend told Allen his beer was right on the money and advised that he taste it again in a year. “I took his advice and did not go near it again for a full year. I tasted it again after a year had passed and, sure enough, it was starting to taste like lambic. Still bad, but you could just detect the beginnings of a potential lambic in there,” he says.
Allen says it improved dramatically in its second year of aging. After 18 months it was nearly drinkable and was really coming into its own. After 24 months he was satisfied with his efforts. It was lambic, to be sure.
“The difference is staggering. It’s quite good now, with a distinct lambic profile. The brett ‘horse-blanket’ character is very assertive, it’s very effervescent with tiny champagne bubbles. It has no hop character at all, which is the norm for the style. I think it will continue to improve over the next few years,” he says.
Since you obviously want to keep lambic organisms out of your other beers, Allen advises lambic brewers to use only glass for all fermentation and culturing, or use old plastic containers that are ready for the trash, anyway. He used old hoses and siphon gear and discarded it all afterwards.
“The one mistake I made was bottling it in 22-ounce bombers. Even for lambic fans, that’s a lot of lambic to drink in one sitting. Next time, I’ll use smaller bottles.
Tooty Frooty, Man
Lambic’s acidic, sour nature makes it a perfect foil for fruit. Traditionally, lambic brewers add different fruits to produce different beers, each with a special name. Peaches make peche. Raspberries make framboise. Cherries make kriek. The commercial examples run from very dry to very sweet and everything in between.
Ralph Colaizzi, a homebrewer in Pittsburgh, used whole cherries to make his own version of kriek. “I would prefer raspberries but haven’t made a framboise yet because I wanted to try a kriek first. I used 10 pounds of frozen whole cherries, thawed and added to the fermenter. Next time, I’d use even more cherries since the fruit character is more subdued than I wanted,” Colaizzi says.
It’s important to use whole fruit when you make fruit lambic, because the flavor of the pit lends an important characteristic to the finished beer. In Belgium, orchards of small, black, sour cherries are grown especially for the brewing of kriek. These cherries are unavailable in the United States, but regular cherries make an adequate substitute for homebrewers.
The Sourmash Method
In the appendix of his landmark work The New Complete Joy of Homebrewing, Charlie Papazian describes a sourmash method to encourage bacterial growth to make a lambic facsimile. Papazian’s method requires a little barley malt, which is loaded with bacteria, used to contaminate warm wort to develop lactic acid sourness. The method will work with either extract or mash-based wort.
However, lactic sourness is only one component of the lambic flavor profile, and Papazian’s recipes also require fermentation with Brettanomyces yeast to complete the process. His method was developed before bacterial cultures were widely available through the homebrew supply network.
Homebrewer Colaizzi has experimented with the technique. “I used the sourmash method a long time ago for a lambic kriek. The sourness was there, but all those other bacterial-based tastes and the typical barnyard aroma and flavor were greatly missed. I have used a sourmash successfully with other beer styles, most notably several Flanders brown ales.
“The Flanders brown is an attempt to duplicate Liefman’s Goudenband. Although the sourmash technique has gotten me closer, the recipe needs a bit of work. I get a nice sour brown ale, but it falls short of the complexity of well aged and blended flavors in the target. This is an ultimate quest for me. I love Goudenband; in fact it is my favorite beer other than the one in my glass. Some day I will perfect it, I hope. In the meantime all the attempts have been great beers,” Colaizzi says.
Passion Flows with Lambic
Like many fans of the style, Colaizzi is passionate about lambic. “I love the style! I have spent a lot of time and effort over the years to seek out lambics to taste. Pennsylvania’s beer distribution system makes finding many of the more renowned brands difficult. I’ve always been intrigued by the spontaneous fermentation method and how it creates such a complex and enjoyable brew. Every bottle of lambic I’ve ever tasted has been a unique tasting experience,” he says.
Colaizzi says the technical challenges posed by the style gave him incentive to try his hand at it.
Colaizzi uses American ale yeast for his primary fermentation. “I’ve always used Chico ale for the primary because I wanted a neutral yeast flavor. After five to seven days, I add the brett and pedio cultures. I use Brewtek’s Brettanomyces Lambicus and their Pediococcus strain. I’ve considered using Kloekera but haven’t obtained any.
“After a month or two, I add dregs from every lambic I drink. I hope to get more of the unusual microflora introduced this way. This is a very odd brew every time because I forgo the usual racking and just leave it all in the original carboy until fruit is added. After six months or so, I add the fruit by racking the beer into a plastic fermenter with the fruit but stir up most of the sediment in the process.
“I let it continue for another six months, then rack it off the fruit and bottle it,” says Colaizzi.
Colaizzi has a few lambics cellaring in his brewery.
“The gueuze, my first, is three years old and never developed the character I hoped for. It’s very sour but lacks complexity and has very little brett character. The kriek is two years old. It has a very pronounced acetic/vinegar aroma and a bit in the flavor. It has improved in the past six months, so my hopes are up. The brett is very evident in this one as well as many other complex flavors. If the vinegar notes mellow, it may be good. At this time it would not win any competitions.
“I’d be more careful with aeration when racking to the bottling bucket. The kriek was just wonderful when I bottled it but after a month or so the vinegar character appeared. I believe the oxygen introduced by racking triggered the growth of the acetobacter,” Colaizzi says.
“Blended” Yeast
Wyeast sells a lambic blend smack pack, which contains both yeast and bacteria cultures. While pitching both up front will generate some “horse-blanket” character, Colaizzi says it’s better to pitch the organisms separately.
“By pitching a blend you will get some horsey, leather-type character in your beer in time. This can produce a satisfying beer but will not give it the classic lambic character.
“I suggest seeking out a Pediococcus strain and perhaps some Kloekera. The pedio is available from Brewers Resource as well as a Brettanomyces strain. If you really want to do it authentic, you need to go for the biohazard stuff,” Colaizzi says.
So let your hops go stale, let your wort get contaminated, and mark your calendar for your own lambic tasting, in a year or two!
Ralph Colaizzi’s Lambic
(5 gallons)
OG = 1.048
FG = 1.004
Ingredients:
• 4 lbs. unmalted wheat
• 5 lbs. DeWolf Belgian pale malt
• 5 lbs. cara-pils malt
• 2 oz. aged Fuggle or East Kent Goldings hops, 2 years old or oven-aged
• Chico ale yeast
• Brettanomyces culture
• Pediococcus culture
• 3/4 cup corn sugar for priming
Step by Step:
Crush and mix grains. Heat 2 gals. water to 185° F. Stir the grains into 1 gal. of the water. Slowly add more water, stirring constantly, until temp. reaches 130° F (you may not need all the water). Rest for 30 min. Add about 1 gal. boiling water to raise temp. to 140° F. Hold for 30 min. Add about 1.5 gals. boiling water to reach 155° to 158° F . Hold for 60 min. or negative iodine test. Add 1.5 gals. boiling water to reach 170° to 175° F. Sparge with 4 gals. water at 175° F, collecting 6.5 gals.
Bring to a boil and boil 30 min. Add hops and boil 90 min. more. Chill to 70° to 75° F and pitch yeast.
Let the yeast work for two weeks, then pitch the Brettanomyces. Let the Brett work for two weeks more, then pitch the Pediococcus and let it work for another two weeks before priming and bottling.
Ralph also pitches the dregs from bottles of commercial Lambic he happens to drink during the fermentation.
To oven-age hops, Ralph lays them on a cookie sheet and bakes them at 200° F for around 30 min.
Fermentation temperature varies between 68° and 75° F, depending on the season.
OG = 1.048
FG = 1.004
Gravities are approximate, because every batch of Lambic tends to behave differently.
Note:
In Belgium gueuze is made by blending old and new lambics. The new brew contains some residual sugar and acts as bottle-priming to set off the secondary ferment in the bottle. To make your own bottle-conditioned gueuze, bottle with 3/4 cup priming corn sugar, as usual.
Chuck Allen’s Lamp Lighter Lambic
(5 gallons)
Ingredients:
• 3 lbs. Belgian pale malt
• 1 lb. Belgian wheat
• 1 lb. Belgian cara-Vienne, 24° Lovibond
• 4 lbs. Dutch extra light dry malt extract
• 1 oz. Styrian Goldings hops (5% alpha acid), for 60 min.
• 35 ml YeastLab Belgian Trappist Yeast A08
• 35 ml YeastLab Brettanomyces lambicus yeast
• 35 ml YeastLab Pediococcus cerevisiae (P. damnosus) bacteria
Step by Step:
Add 1 gal. water to brew pot and bring to 135° F. Add all pale and wheat grist and stabilize at 124° F. Let stand with no heat for 30 minutes. Bring 2 qts. plus 1 pint water to a boil and add to mash to bring temp. to 145° F. Add heat to 156° F (I had to add 1 pint cold water). Add specialty grains and let stand for 30 minutes.
Remove grains and sparge with 1 gal. water at 170° F. Add extract and hops. Boil for one hour. Strain into carboy with 1.5 gals. cold water, aerate, and pitch Trappist yeast. Note: Yeast was cultured twice to ensure sufficient population, OG = 1.063.
Primary fermentation should last seven to 10 days. Rack to secondary, SG = 1.018.
Prepare Pediococcus starter and let culture for at least one week.
Rack to tertiary, SG = 1.018.
Pitch Pediococcus and begin culture of Brettanomyces. Culture twice to obtain large quantity. Allow Pediococcus to develop for two weeks.
Rack to fourth, SG = 1.016.
Pitch culture of Brettanomyces, let it work for two more weeks.
FG = 1.021
Alcohol = 4.41 percent by weight, 5.51 percent by volume.
The gravity was up slightly in the end. Chuck Allen believes this was caused by some fermentables that entered the beer with the large volume of Brettanomyces starter culture.
Prime, bottle, and wait it out until it becomes drinkable.
