Tag Archives: Jean-Pierre Van Roy

Wild Yeast


Posted by Aschwin de Wolf

Chris White and Jamil Zainasheff’s Yeast: The Practical Guide to Beer Fermentation is a thorough review of the subject of yeast, with the practical (home)brewer in mind. It is mostly a treatment of commercial brewer’s yeast but there are some interesting observations about wild yeast, too. The authors define wild yeast as yeast “that is not in the brewer’s control.” For example, commercial Brettanomcyes is not wild yeast but native strains of Saccharomyces that (unintentionally) are introduced during cooling of the wort or barrel aging would be. Of course, today’s commercial strains of Brettanomyces may still have a lot in common with yeasts that are found in the wild, but one could imagine a scenario where the use of Brettanomyces becomes so popular that commercial yeast sellers increasingly select these strains for certain properties. As a consequence, wild yeast is not characterized by its aroma and flavor properties (such as tartness or funkiness) but by its involvement in (ambient) spontaneous fermentation.

There are a number of distinct traits that have been retained in wild yeast. Wild yeasts are usually diploid, form spores, and are still capable of mating. Commercial yeast, in contrast, has lost this ability because mainstream brewers desire consistent characteristics from their yeast. Wild yeast usually has low flocculation, which can produce higher attenuation because the yeasts will not quickly drop or rise in the wort. In commercial yeast, however, such a property is not desirable for many beer styles, where a quick and clean beer is the goal.  Unlike wild yeasts, which have evolved to compete against each other, commercial yeast can often co-exist and ferment at similar rates.

The book also includes sections on Brettanomyces and capturing wild yeast. Although the name Dekkera is often used interchangeably with Brettanomyces, it is only Brettanomyces that is of the non-spore forming type. One of the intriguing things about Brettanomyces, much to the chagrin of wine makers, is that it produces the enzyme Beta-glucosidase, which can convert the wood sugar cellobiose into glucose, a phenomenon that is more prevalent in new barrels that have higher concentrations of cellobiose. Brettanomyces is quite sensitive to oxygen, with moderate concentrations most favorable to its growth, and lower and higher concentrations, unfavorable. Increased oxygen produces more acetic acid as a fermentation product.

Instead of inoculating wort with commercial Brett, some (home)brewers aim to capture real wild yeast for fermentation. There is no shortage of methods for doing this, including ambient exposure of the wort, fermentation in “infected” barrels, the use of wild fruit and herbs to start fermentation, or using dregs from the bottles of traditional lambic brewers. Of course, such methods usually introduce souring bacteria as well, and the art is to discover and perfect a method that leads to consistent, favorable outcomes. Because many brewers prefer not to waste multiple batches of wort on spontaneous fermentation experiments, and the yeast captured in the wild may not be sufficient to start a healthy fermentation, one approach is to create ambient spontaneous starters (there is a lot of information about creating conventional starters in the book). At this stage, such efforts are still largely the work of some adventurous (home)brewers, and documentation of such efforts is still in its early stages (the Mad Fermentationist blog is an excellent resource). In the case of spontaneous starters it is important to avoid sampling at an early stage, where aerobic conditions, higher pH, and low alcohol still permit the presence of dangerous pathogens.

Because the book is mostly written for brewers who have control over their yeast and fermentation, a lot of information is not completely applicable to brewers who use spontaneous fermentation or incorporate spontaneous fermentation. But there is some information that is interesting for “wild” brewers as well. For example, proper wort aeration is important for healthy yeast growth but brewers who use barrels for (primary) fermentation may have problems in getting enough dissolved oxygen at the start of fermentation. The authors report on a New Belgium method where olive oil was added to the wort to supply the sterols that yeast cell membranes require for proper structure and function. One also wonders how the use of coolships (with their large surface to volume ratio) influences initial wort aeration. Temperature is another topic that affects conventional brewers as well as those using wild yeast. As far as I am aware, traditional lambic brewing does not necessarily exclude temperature control, but I think it is safe to assume that most fermenting lambic wort is subject to substantial seasonal and overnight temperature changes that would be contra-indicated for conventional brewers (Cantillon’s Jean-Pierre Van Roy once looked horrified when I asked him about active temperature control). It would be quite helpful to quantify and characterize the effect of ambient temperature fluctuations on wild yeast and bacterial growth, fermentation, and flavor.

Much of the information on yeast growth, handling, storage, and labs is not applicable to spontaneous fermentation but some of the techniques (such as wild yeast tests and forced fermentation) can be used by adventurous brewers to study wild yeast and the conditions that influence spontaneous fermentation. Ultimately, there is an increasing need for an extensive book treatment on (home)brewing with non-conventional and wild yeast. Modifying or ignoring (!) procedures for brewing with domesticated yeast will only take you so far, and the homebrew recipes that can be found in some classic lambic and wild beer books give little guidance about expected fermentation behavior and troubleshooting. Of course, no matter how much our knowledge about spontaneous fermentation grows, beer that is produced in this way will always have more variability than beer that is produced with domesticated yeast under highly controlled conditions. But this is also one of its strengths, and like authentic wine, can lead to surprising results. Many readers of this blog will agree that the best beer in this world remains a product of spontaneous fermentation. If you brew conventional beer in addition to wild beer, Yeast is an invaluable resource.


Jeff Sparrow on wild brews


Posted by Aschwin de Wolf

Jeff Sparrow’s Wild Brews: Beer Beyond the Influence of Brewer’s Yeast is a major contribution to the literature on lambic beer. In this book the author does not only discuss traditional lambic but Flanders red ale, Flanders brown ale, and contemporary (American) wild ale as well. If anything, this book is testament that spontaneous fermentation and brewing with other yeasts then Saccharomyces is not dead.

After being introduced by New Belgium’s Peter Bouckaert, the book starts off with the obligatory account of how the author became interested in the beers he  loves to write about. In this case the author is traveling in in Europe, ends up in Chez Moeder Lambic in Elsene, Belgium, orders a lambic “with some odd tropical fruit” and is told by the bartender to try Cantillon Rose de Gambrinus instead. This experience, and a later experience with a vintage bottle of Liefmans Goudenband (old recipe) set the stage for an enduring interest in the wild brews of Belgium.

The recovery of traditional lambic and the movement to brew wild ales in other parts of the world raises the obvious question if lambic can be brewed anywhere else than Brussels and the Payottenland. Brewer Frank Boon reportedly said “you can’t” but Cantillon’s Jean-Pierre Van Roy  believes that spontaneously fermented beer can be brewed  in other places in the world. These answers are not mutually exclusive. If lambic beers are defined as spontaneously fermented beers that are brewed in Belgium’s Payottenland, it is evident that lambics cannot be brewed in any other part of the world. If the defining character of lambic is true spontaneous fermentation, all bets are off. And if lambic is defined solely by its flavor profile, the character of lambics can be approached by controlled fermentation with non-traditional yeasts and bacteria. In his book 1990 “Lambic”,  Jean-Xavier Guinard argues persuasively that the temptation to ride on the popularity of lambics should be resisted and that this label only needs to be used for the traditional brews of the Payottenland. On the other hand, when brewers in other parts of the world employ the authentic traditional techniques such non-Belgium lambics could help to save the tradition from extinction.

Sparrow devotes some effort to distinguish between Flanders red ales (sour ales), Flanders brown ales  (oud bruin) and lambics. In the case of lambics such distinctions are clear but the attempt to distinguish red ales from brown ales looks more challenging.  One cannot just tweak a little with another beer style and get a lambic but the dividing line between the Flanders ales can appear quite arbitrary, although one could mention that the the presence of Acetobacter sp.  contributes to the more pronounced presence of acetic acid in the reds. But reading his account of the Flanders sour ales, it seems that these beers are more vulnerable to disappear than lambics. This is ironic because modern examples of such beers are produced in ways that would be considered taking lazy shortcuts by traditional lambic standards. This raises the question of how the production of a traditional Flanders sour ale be distinguished from a traditional lambic, a topic that is discussed at various points in the book.

The history of wild brews is covered in some detail, including a brief discussion of the American Wild Ale style. Sparrow expands on the history of lambic brewing given in Guinard. As the author states, “lambic can lay claim to being the oldest existing beer style in the world”, its first written documentation going back to around 1320. The most infamous lambic variant must be faro, “the beer which is drunk twice”, a characterization that dates from the time that waste-polluted Senne River water was used to brew this sweet lambic. Discussing the practice of blending and diluting lambics, the author notes that some hint  “that the founder of the Belle-Vue lambic brewery-pub in Brussels was not well respected and produced his lambic with help from beer discarded from other breweries and  returned from cafes.”

Although most lambics that are consumed today are gueuze and fruit lambics, one hundred years ago 90% to 95% of lambics were sold straight. Lambic brewers Cantillon and De Cam have bottled unblended aged lambic, but it is not likely that this style will catch on beyond locals, a small group of lambic connoisseurs and perhaps some adventurous wine drinkers any time soon. Sparrow mentions that traditional lambic brewers consider  the differences between lambic and wine and between Gueuze and Champagne very small. Quite remarkably, the author also mentions that in Eastern Brabant the traditional white (wit) beers were produced by spontaneous fermentation as well. Fruit and herbs were often used in the production to balance the sourness of the beer. The addition of herbs has remained a staple of Belgian white beers such as Hoegaarden but the tradition of spontaneous fermentation has been abandoned.

The third chapter about drinking wild beer has lot of information (including a number of maps) about most of the major existing producers of traditional lambics and wild ales and  makes the book quite useful as a reference. There are also interesting tidbits of information about the evolution of some brewers, which often means the transition from a traditional product to something with more mass appeal (such as the reduction of aged beer in Rodenbach Classic to make it sweeter). This chapter really shines in its description of the traditional lambic brewers; their formation, history and brewing approach. Sparrow’s description of 3 Fonteinen’s unorthodox “temperature controlled” barrel stores has taken a completely different meaning since the 2009 disaster that cost the brewery most of its years product and contributed to DeBelder’s decision to stop brewing and return to blending. The United States is also discussed and includes some interesting information on smaller experiments with wild ales around the country. Also featured, of course, is Russian River, the California brewery that has done a lot to promote sour ales in the United States and who can give many Belgium brewers a run for their money.

The technical treatment of lambic brewing covers much of the same ground as Jean-Xavier Guinard’s 1990 book on the topic but adds a lot of interesting details, photos (including microscopy images) and tables.  In the case of Sparrow’s book there is, of course, also the technical treatment of the production of Flanders reds and browns. Most impressive, and somewhat of a neglected topic in Guinard’s book, is the extensive discussion of the characteristics, selection and maintenance of barrels, an element of traditional lambic brewing that requires a lot of expertise, which further adds to the mystique of lambic brewing. In his discussion of barrel choice, the author mentions the ability of some lambic connoisseurs to detect the original use of a “new” barrel in a blend.  Breweries such as Belle-Vue, Cantillon, and Oud Beersel also use chestnut barrels in addition to oak.

The technical and procedural treatment of lambic is completed with a chapter about blending, and that of Gueuze blending in particular. As the author notes: “Gueuze blending is an art. The traditional gueuze blender expresses himself using a liquid media the same way a painter uses paint and canvas.”

Wild Brews is great book for  lovers of traditional lambic.  Highly recommended.