BoomIslandFramboise2017

Mixed Fermentation

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From-Kevin
Framboise is our newest member to join the Spontaneous Series. These Lambic type beers sit in the oaken barrels for well beyond 12 months before they are opened up for a sample to evaluate their maturity. It is at that point that several decisions are made. First, has the beer developed not only acidity, but also has it developed the layers of depth that can only be achieved through a very, very long “mixed fermentation”.  A mixed fermentation is one in which a cocktail of different microbes are going to work and simultaneously breaking down the various food sources present in the liquid. Choices made here by the taster and blender will result in the destiny of the beer.
In Belgium, fruit (and I’m not talking about a slice of orange) has been used in beer production for hundreds of years. Especially with regard to the production of Lambic beers. Additionally, the fruit I find most frequently associated with Lambics is the Raspberry. “Framboise” in French for southern Belgium or “Frambozen” in the Dutch speaking north, raspberries have been found to be the perfect accompaniment to the acidic depth of a spontaneously fermented Belgian Lambic.
In our case, I felt that the blend lent itself very nicely to partnering up with a healthy dose of raspberries. It was at about the 14th month of fermentation when the raspberries were added. Of course, all those wacky non-traditional brewing microbes went nuts consuming the additional sugars present. The beer actually foamed out of the barrels at that point. I gave it a couple more months to ferment out all the remaining sugars. Next, we hand bottled the beer one by one with a little additional fermentable sugar and finished it with a cork and cage. The bottles then underwent an additional fermentation inside the bottle to develop its natural carbonation, which is exactly the same as the Champagne bottling process referred to as Champagne Méthode Classique.
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I can’t conclude the blog without referencing the overly sweetened yet most famous example of Framboise, that of Brouwerij Lindeman’s. A truly wonderful and historically important brewery itself, the Lindeman’s Framboise is not the example I was taking inspiration from. Perhaps more applicable examples in our case would be those made by Cantillon, Drie Fonteinen, Oud Beersel or Timmerman’s.
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This Framboise is going to be dry but with very complex layers of depth from both the wild fermentation in the barrel as well as all the fruit. Its appearance is totally influenced by the raspberries. It pours a deep ruby red with a quickly dissipating head due to all the head retention elements being consumed along the way. You will get the fruit on the nose, but don’t over chill the bottle. The fruit comes out when the beer is a few notches above fridge temperature. We only bottled two barrels worth this year so grab it quickly. I can’t wait to share some fruity sour complexity with all of you!
Lambics are great with food as well, there are some ideas for you:
Fennel, Sun choke and Apple Salad. Tart, clean, and goes well with fruit lambics.
Mussels with beer sauce and of course fries. Anything goes with fries!
Eggs Benedict. Yes, this classic breakfast fix is surprisingly sour beer friendly.
Belgian Waffles. Why not! Top your waffles with some delicious fresh raspberries!
Santé!!!

Kevin

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Keeping up the Belgian Tradition

From-Kevin

Kriek, barrel aged sour beer fermented with cherries. Krieks originated as a variation on another Belgian style of spontaneously fermented beer called Lambic. Lambic producers originated from the area just to the south and southwest of Brussels. It is believed that the region evolved such a tradition of initial open fermentation, then wild or mixed fermentation, in wooden barrels because of the abundance of natural yeast in the air from the many local fruit orchards. Today some breweries which are not in the Lambic region produce Kriek but use other wild or mixed fermentation processes such as a vatted Pale or an Oud Bruin.

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Belgium is fairly unique in the respect that using fruit to ferment alongside wort created from grain has been a tradition for hundreds of years. I like to think of it this way. Belgium is a wonderful little country wedged between Germany which is famous for beer, and France for its wine. (There is a reason why many great Belgian beers come corked and caged, just like Champagne.) The Belgians have taken the best inspiration from those around them and put it all together to bring us the most diverse tradition of brewing we know historically. Today of course, we know American craft beer to push all boundaries. But the Belgians have been doing this for hundreds of years!

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Kevin and Liefman’s brewer

On to the Boom Island Kriek. This beer pays respect to that Lambic tradition of making beer with cherries. Since we are not producing it in the Lambic region of Belgium however, you will not find the words Lambic (or Gueuze – which means blended Lambic) anywhere on our labels. These are registered terms just like Champagne. Our wort, just like Lambic, was produced by what is called a Turbid Mash. This means during the mash, liquid is drained off, boiled, then returned to the pot to gradually raise the temperature through multiple steps. Our wort is then boiled with old, brown oxidized hops. This is also standard in producing Lambic. The old hops have lost most of their aroma and bitterness potential, but still maintain their preservative qualities. This is important to fight back Lactobacillus. But doesn’t Lactobacillus cause sourness? Lactobacillus could cause some sourness, but Lambic brewers have found the acid it produces lacks the depth and complexity which is found in a barrel aged Lambic.

This brings up a little tangent. A relatively common practice these days here in the US craft beer scene is referred to as a “kettle sour”. This is a technique which does use that very microbe, Lactobacillus, to sour the wort over the course of 24-48 hours before it is boiled. Once the desired ph is achieved, the wort is then boiled to kill off all the bacteria. The remainder of the brew process is a “clean” fermentation and the finished beer can be achieved in a matter of weeks. This allows a brewer to quickly produce a couple of German style beers like Berliner Weisse and Gose. One can find many pleasant and tasty examples of this type of beer on the market.

The Belgian approach however is quite different.  As our process continues, we have incorporated a turbid mash and then boiled the wort with oxidized hops. The wort is then cooled and moved to a stainless conical fermenter where it begins fermentation. The top is left open so the now fermenting beer can interact with the ambient air. Next comes the important part. Toward the end of the primary fermentation, the beer is moved into oak wine barrels to rest for more than a year. These recently emptied barrels had been home to sour beer produced by the same method for up to 4 years. The porousness of the wood harbors the litany of microbes which slowly soured the beer in the barrel over the course of at least a year and usually more.

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Cherry Picking in South Minneapolis

Hand picked tart cherries are added to the barrel and after a year the fermentation kicks back into action. After a couple of months, the sugars from the cherries have all been consumed and the beer is ready to bottle. Fresh yeast and a small amount of fermentable sugar is then added to the flat beer at bottling time. The bottles are corked and caged (the Belgians learned this carbonation technique from the Champagne makers of long ago) and a final fermentation takes place in the sealed bottle creating natural carbonation. This is the short story of how our Kriek is produced

 

 

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Stats:

Kriek – 4.8% ABV

Appearance : Light-Red Rose.

Flavor : Slightly tart, nutty and acidic, with a light effervescence and dry cherry halo.

Proost!

Kevin