Editor's note: this post was written by our summer intern/Sour Guru, Mike Tonsmeire, AKA The Mad Fermentationist.

In the next couple months, Modern Times will brew the first four base beers for our barrel-soured mixed-fermentation program! Our goal is to generate a wide range of characteristics in our use of recipes, barrels, and microbes. As we learn which combinations are ideally suited to our brewery, we may begin to narrow our focus, but expect a lot of variants and experiments for the foreseeable future.

For most “standard” beers the path followed from brew day to consumption is a direct and linear one. A batch of wort is created in the brewhouse, it is pumped into a fermentor with yeast, then a bright tank for carbonation, and finally into kegs, cans, or bottles. The batch stays together until it is packaged for serving.

Brewing a barrel-aged sour beer divorces the concepts of a batch of wort from a serving of beer. The sour beer in a bottle was often brewed in different months or years, aged in dozens of barrels, before meticulous blending married them together.

In all likelihood, at Modern Times, several barrels will be selected from the 15 or so initially filled with each base beer to be blended and released as is. A pure expression of each one. Barrels of different base beers may be blended together to create a unique amalgamation. Barrels may be blended to be aged on fruit (or vegetables) in wine totes, while others are dry hopped, infused with spices, or reserved for blending with subsequent vintages. Invariably a few barrels won’t have a desirable flavor profile and will be dumped.

I often hear complaints that many sour beers have interesting flavors, but are overwhelmed by sharp acidity. This is not an arms race. Vinegar is extremely sour, but it isn’t much fun to drink! Our goal is to create a range of tart beers that are complex and interesting, but still pleasantly drinkable.

The Base Beers

Shredder – Single (Recipe)

Pale, bright, and light. Inspired by the table beers brewed at several Belgian Trappist monasteries for the monk’s consumption, but treated in a way that no monastic brewery does. A simple grain bill should allow the oak, brettanomyces, lactobacillus, and pediococcus to do most of the talking. Aged in well used wine barrels to avoid overpowering the delicate base beer. Microbes will likely include some isolated from kombucha and wild honey, along with those from standard sources. A portion of this beer will almost certainly find its way onto local nectarines, peaches, or white wine grapes.

Krang – Lambic-ish (Recipe)

While not attempting to replicate the process of the Belgian brewers who produce lambic and gueuze, this beer is inspired by their amazingly balanced and nuanced results. The recipe is mostly pilsner malt, with a substantial portion of flaked wheat and a touch of oats. It will be fermented with cultures that include those isolated from bottles of Belgian gueuze by a half dozen microbe-nerds (professional and amateur). Herbal dry hops, rhubarb, or edible flowers are options for a few barrels of this beer.

Bebop – Red (Recipe)

Inspired by the red ales of Flanders, but with a balance that is simultaneously less acidic and less sweet. A varied malt bill should provide a depth of malt character to complement the fruity notes derived from both the wine barrel, and mixed-fermentation. Vienna and Munich malt total more than half the grist, providing a soft bready backbone for the dark caramelly-fruitiness of the Special B and CaraMunich. The resulting flavors should pair nicely with red wine grapes, citrusy dry hops, or pie cherries.

Rocksteady – Brown (Recipe)

The strongest and maltiest of the base beers, the concept is borrowed from the provision-strength sour brown ales of Belgium, the Bière de Gardes of France, and their barrel-soured American cousins. The acidity in this beer should be the lowest, allowing toasty and caramel flavors of the specialty malts and dark candi syrup to shine through. Brettanomyces strains which provide dark fruit, leather, musty, and sherry aromatics will complete the bulk of the work. While most of the other beers will be aged exclusively in wine barrels, this one should find its way into some used spirit barrels for a more assertive oak character. Currants, dates, figs or other dried fruits could add depth to this beer, but it probably won’t need it!

Currently, all we have are the internal names for the base beers; they’ll get actual names once they are blended and ready to release.

We will slowly learn which barrels and microbes suit each base beer as we brew them several times over the next few years. The feedback loop for sour beers is much longer than for standard ales and lagers. As a result they’ll take years to perfect.

Sorry to get your hopes up, but the first of these beers won’t be released at the tasting room until at least the summer of 2014. Luckily we have a few tart beers that won’t be aged in barrels that should help to sustain you until then!