Tag Archives: Brettanomyces

Mikkeller Yeast Series: Brettanomyces


Posted by Aschwin de Wolf

Admittedly, I was a little hesitant about this beer because Mikkeler seems to show little restraint in what it releases to the market. But this “educational” beer designed solely to showcase the Brettanomyces yeast was too tempting to leave untouched and I was not disappointed at all. The base for this beer (and all the others in the yeast series) is a strong pale ale, and it was brewed and bottled by Mikkeler at the Proef Brouwerij in Belgium.

Brettanomyces pours a dark orange / amber with a good two finger head. For an 8% beer I find the aroma quite crisp and restrained with notes of musty tropical fruit, green apple, and hops. I am not sure about the brettanomyces strain(s) used for this beer, but I suspect it may have been one of the milder strains (Claussenii?) – not of the barnyard, band-aid variety. The beer is mildly tart and has a nice European hop character to balance out the malt and yeast expression. Not terribly complex, but that is a good thing in this beer, I think. The finish is dry and pleasantly bitter. Not too cloying or sweet, inviting one to take another sip. Carbonation is quite high, which could be the result of the higher attenuation induced by the brett during bottle fermentation.

Brettanomyces is too strong to be an easy-drinking session beer. But considering the alcohol percentage, I found it quite smooth and light. Although this beer was designed to showcase the brettanomyces yeast, I think it would not have been nearly as refined without the generous amounts of hops. I can see how this beer could be disappointing to people who want more fireworks from the brett, but simply judged as a balanced beer, I think it is a good effort.


Anchorage brews with brettanomyces


Posted by Aschwin de Wolf

When I ventured into the low-temperature walk-in beer section in my local Whole Foods recently, my eye caught no fewer than three bottles from Anchorage Brewing that all said “with brettanomyces:” a Saison (Love Buzz), a Wit Bier (Whiteout), and a double IPA (Bitter Monk). As a matter of fact, Anchorage Brewing aims to brew all barrel-aged, brettanomyces-influenced beers. Since I have let loose all kinds of brettanomyces on my own home brews, I was quite interested to experience the effect of on these different beer styles.

I first tried the Saison, which clocks in at no less than 8% alcohol and 40 IBU, which is not trivial for the style. While the label mentions rose hips, peppercorns,  fresh orange peels, and Pinot Noir barrel aging, I did not seem to get a lot of this. The beer pours a beautiful cloudy, dark orange and has pronounced notes of brettanomyces, grass, lemon and a faint biscuit sweetness. The hops definitely make their presence known and carry the beer towards a long, off-dry, bitter finish. As it warms up, the (sticky) sweetness becomes a little more pronounced, but the brett and hops keep it in check. This is not a session beer but I would not call it a sipper either. I was expecting a little more complexity and I could see people mistaking this for a Brett-enhanced IPA instead. Dialing down the alcohol and letting the herbs shine may lead to further improvement.

The next Anchorage beer I tried was Whiteout. Whiteout pours a very light cloudy yellow. The first thing that entered my mind when I smelled it was “lambic.” Whether it was the contribution of the lemony Sorachi Ace hops, the wheat, or some other fermentation product, the aroma evoked a good, earthy, Belgian Gueuze, with a hefty dose of barnyard and spice. This beer tastes as great as it smells; dry, crisp, minty, and tart with a long bitter finish. The coriander contributes a nice herbal note and the Chardonnay barrel aging adds some buttery smoothness. As the beer warms up, the Belgian yeast expresses itself without throwing around too many esters. Mouthfeel is on the lighter side and the beer is very effervescent. As a crisp 6.5% alcohol beer, this is a very drinkable beer.

The third beer I drank was their Brett-enhanced Belgian-style double IPA. I do not recall tasting a double IPA with secondary brettanomyces fermentation before so I was quite curious about this one. Bitter Monk pours an opaque dark orange and leaves quite a bit of lacing during consumption. As would be expected from a double IPA, the nose reveals major hops – plus some funk from the brett. I am not a big fan of  (American) citrus hop varieties but that is not the brewer’s fault. I also detect green apples, banana, and grassy notes. For a high gravity beer, the sweetness is not too oppressive and it seems that the brett consumed some additional sugar. The beer tastes relatively dry for the style and ends on a long bitter note. Carbonation is quite low but I tend to like it that way. For a double IPA this beer is quite drinkable, even crisp. It is not as complex as the Whiteout beer, or perhaps it is under the surface, as the 100 IBU hops ensure a beer dominated by hops. For someone who is not a big fan of the double IPA style, this is not bad at all.

So how does the brettanomyces contribute to these three beer styles? I am inclined to say: Brettanomyces giveth and Brettanomyces taketh away. It seemed that in the case of the Saison, something might have been lost. In the case of the white beer, it produced a stellar, fascinating beer. As for the Belgian double IPA, a hop bomb remains a hop bomb, but it seemed to confer a crisper, drier character and some unmistakable earthiness. So Whiteout is the clear winner for me. Of all three brews, it allowed the other ingredients and barrel-aging to shine. Yet again, it reinforced my preference to keep the alcohol down in such beers. And I may have to get some of these Sorachi Ace hops!


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.


Authentic wine


Posted by Aschwin de Wolf

Jamie Goode and Sam Harrop’s Authentic Wine: Toward Natural and Sustainable Winemaking is the most extensive (technical) review of natural wine making to date. The authors prefer the term authentic wine to recognize the fact that wine is not a spontaneous product of nature but requires a competent winemaker. As the authors point out on many occasions, “natural” is a matter of degree. So why aim for non-interventionist wine making in the first place? The answer that appeals most to the authors is that it allows for the purest expression of terroir. A fair degree of non-interventionism is a necessary, but not sufficient, condition for making good wine. As such, the authors do not reject, and in some chapters seem to strongly support, some manipulation of the wine to allow for the best expression of terroir, a perspective that no doubt is controversial with those who practice natural wine making because they value non-interventionism as such. One could argue that the writers are terroirists first, and non-interventionists second.

I think the rejoinder to such a “terroir through manipulation” perspective would be to argue that if non-interventionist wine making leads to a poor expression of terroir, then either the wine maker is not creating the proper conditions for the grapes and wine to develop, or one is trying to make wine in an area (i.e., soil, climate) that is simply not suitable for their choice of grape, style, or even wine making at all. The authors actually seem to be quite sympathetic to this outlook because the book is full of examples of how many wine “faults” can be avoided without manipulation of the end product. Ultimately, the implied verdict seems to be that natural wine making is an advanced form of wine making for a specific subset of consumers, and does not permit a lot of room for errors or ignorance. I think there is a strong parallel with spontaneous fermentation in beer making here. Despite the rhetoric about letting nature take its course, lambic brewers usually have a deep and thorough understanding of the conditions and variables that affect their beer, even if they do not always express this in the technical language of brewing science.  In today’s world, natural wine making and spontaneous fermentation of beer is a choice and one that is usually made by people who accept and embrace the challenge — hence the (mostly) superior results.

One of the most interesting chapters in the book is about ripeness and alcohol levels. The authors show how syrah performs in cool and warm climates, and how picking times influence terroir expression. Picking the grapes too early will result in low alcohol, unripe, and harshly tannic wines, and picking the grapes too late will produce high alcohol, low acid and uncharacteristic “soupy” wines.  Of course, personal preference matters and that is why the authors show an “optimum window for terroir expression” instead of one single time point. For example, I personally prefer wines that are very dry, lower in alcohol, with good acidity and tannins, with restrained green notes, which requires relatively early picking of the grapes. As a general rule, writers on natural wine agree that (excessive) new oak and high alcohol overwhelm the expression of terroir. The authors quote winemaker Scott Burr: “alcohol is a masking agent…so taking it away reveals what’s there.” I am inclined to think that this applies to many beer styles as well. For example, a high gravity beer with a lot of post-fermentation residual sugar is not ideal for showcasing the differences between different fresh hop varieties. It may not be a coincidence that most lambic producers, and Cantillon in particular, keep their alcohol percentages on the lower side of the spectrum and generally avoid new oak.

This book stands out for a relatively detailed discussion of yeast and fermentation in wine. In contrast to brewing, the use of the indigenous (“wild”) yeast on the grapes has never really gone out of style in wine making, despite the increasing popularity of inoculating wine with commercial yeast. I suspect that, aside from the more traditionalist culture associated with wine, a major reason is that the differences between the results of spontaneous fermentation in wine and the use of commercial yeast in wine are smaller than the outcomes for beer. As a general rule, spontaneous fermentation in beer leads to distinctively dry, tart and funky beers that do not appeal to the average beer drinker. In wine, spontaneous fermentation can produce funkier wines, but the degree of funk is not of the magnitude that we see in beer – although it strikes me that it should be possible to “direct” a natural wine towards a far more funkier expression, something I suspect some French natural wine makers deliberately aim for.

Brewing with brettanomyces, or even 100% brettanomyces, is now quite popular in craft beer brewing. In wine making, brettanomyces is considered a “fault,” even among many natural wine makers. The reasoning is that brettanomyces inhibits the expression of fruit and blurs the distinctions between grapes and terroir.  Having said this, some of the most prestigious red wines have a faint brett character that some feel adds complexity. Even the authors consider the possibility that the presence of brettanomyces might work in some specific wine styles. I have tasted a number of wines where the presence of brettanomyces was unmistakable — in some wines I agree that it impoverished the wine, in others I think it positively amplified the dark, brooding, and rustic character of the wine. As far as I am aware, unlike beer drinkers, wine drinkers never express an explicit liking for brettanomyces. Whether this psychological barrier reflects a fundamental, and correct, recognition that brett generally has no place in good wine, or a reluctance to embrace the unorthodox results of spontaneous fermentation, remains to be seen. What is clear, however, is that brewers of funky and sour beers have a (practical) knowledge about the complexities of brettanomyces fermentation and expression that is usually absent among wine writers.


Avery Brabant


Posted by Aschwin de Wolf

During a recent business trip I located a bottle of Avery’s Brabant. Brabant is a dark wild ale that was fermented with two strains of brettanomyces and aged for 8 months in Zinfandel barrels. The beer was bottled on February 10, 2009, limited to 694 cases and has an alcohol percentage of 8.65. The recommended serving temperature is between 45 and 55 Fahrenheit but we poured it a little colder to follow its evolution as the beer warmed up.

The color is mysterious, with dark orange overtones and resembling molasses.  No light passing through here. The smell is complex and evokes bananas, liquorice, prunes and chocolate. The brett is certainly there but, overall, the aroma is fairly clean. When the beer warms up, the roasted and vanilla notes are more pronounced – the vanilla presumably from the oak barrels. The beer is mildly tart but there is also a pleasant bitterness among the dark fruit notes that keeps the generous malt bill in check. Brabant finishes long and dry. Mouth feel is surprisingly thick, even a little syrupy, and creamy smooth. Carbonation is almost non-existent and may rank among the lowest I have encountered in an American wild ale – but it works quite well in this brew.

On paper I should not have cared for this beer because of its high gravity and new oak aging, but I thoroughly enjoyed it. The roasted and black malts blend quite well with the brettanomyces strains and the vanilla notes add something to the beer instead of suffocating it (as happens in many New World wines and “barrel-aged beers”). Unlike some other high alcohol wild ales, Avery’s Old Jubilation-derived Brabant clearly aims at the darker side of the beer spectrum. I think that the inclusion of dark and roasted malts is what makes this beer succeed where many other high gravity wild ales fail to convince.

As a lover of (imperial) stouts I have always been intrigued by the idea of a wild ale with roasted malts, but so far I have not been too impressed by the sour stouts I have sampled. The combination of roasted malts and souring bacteria does not seem to work for me. In Brabant, the brett-induced tartness is more subtle and integrated and this beer has actually made me more optimistic about my own stout that is currently in secondary fermentation with Brettanomyces Bruxellensis. After all, in the past, most stouts were wild!