Unearthing History, Brewing Innovation: A Taste of the Past Reimagined

A Historical Collaboration: Brewing Inspired by Ancient Peruvian Wisdom

This remarkable beer recipe emerged from a deep collaboration with the Field Museum of Natural History in Chicago. Its creation was profoundly influenced by archaeological findings, specifically those dating back over a millennium to the Wari civilization of southern Peru. This partnership underscores a dedication to historical accuracy, allowing modern brewers to reinterpret an ancient beverage.

Brewing Parameters: Essential Specifications for Crafting Your Own

For those eager to embark on this brewing journey, precise measurements and targets are crucial. This recipe is designed for a 5-gallon (19-liter) batch, aiming for a brewhouse efficiency of 72%. The initial specific gravity (OG) should be around 1.044 (11°P), finishing at approximately 1.010 (2.5°P). The beer's bitterness, measured in IBUs, is kept low at 8, resulting in an alcohol by volume (ABV) of 4.5%. These specifications provide a clear framework for consistent results.

The Foundation: Grains and Their Role in Flavor and Color

The core of this unique ale lies in its carefully selected grain bill. It includes 6.2 pounds (2.8 kg) of pilsner malt, providing a light, crisp base. A significant addition is 1.7 pounds (771 g) of purple corn, which imparts distinct flavor notes and the characteristic hue. To aid in lautering and prevent a stuck mash, 1 pound (454 g) of rice hulls are incorporated. Finally, 6.5 ounces (184 g) of honey malt contributes a subtle sweetness and a touch of complexity to the overall profile.

Aromatic Accents: Hops and Unique Additions

The hop schedule for this brew is minimal, focusing on delicate bitterness rather than prominent hop aroma. A mere 0.6 ounces (17 g) of Saaz hops are added at 60 minutes into the boil, targeting around 8 IBUs. What truly sets this beer apart is the inclusion of 0.25 ounces (7 g) of pink peppercorns at flameout or during the whirlpool. These berries, known as Schinus molle, introduce a unique, subtly spicy, and aromatic dimension that complements the corn's earthiness.

The Living Element: Yeast and Fermentation Techniques

The fermentation process for this chicha-inspired ale employs a mixed culture, featuring both Lactobacillus and a saison yeast strain. This combination is key to achieving the desired tartness and complex flavor profile. Brewers are encouraged to allow the fermentation to proceed at ambient temperatures, with the option to let the temperature rise to 78–80°F (26–27°C) depending on the specific mixed culture used. This approach mimics traditional chicha methods, contributing to the beer's distinctive character.

Preparation Steps: From Corn Treatment to Mash and Boil

The brewing process begins with crushing the purple corn and soaking it in 4 quarts (3.8 liters) of water. A crucial step involves skimming off the germ particles that float to the surface, as their oils can negatively impact the beer. Four ounces (113 g) of pilsner malt are then milled and combined with the corn for a cereal mash, heated to 158°F (70°C) for 20 minutes before boiling. Concurrently, the remaining grains are milled with rice hulls and mashed in at 150°F (66°C). The cereal mash is then integrated, raising the combined mash temperature to approximately 158°F (70°C) for a 60-minute rest. After recirculation for clarity, the wort is run off into the kettle, sparged, and topped up to achieve about 6 gallons (23 liters). A 60-minute boil ensues, with hop and peppercorn additions as scheduled. Post-boil, the wort is chilled to 70°F (21°C) before pitching the mixed culture, followed by fermentation, crashing, and packaging.

Special Considerations: Purple Corn and Fermentation Nuances

For the purple corn, or 'Maíz morada,' sources include online retailers or Latin American grocery stores. Degerming the corn is vital to avoid off-flavors from its oils; gentle crushing and soaking allow the germs to float for easy removal. As an alternative, flaked corn can be used, though purple flaked corn is not readily available, making hibiscus or strawberries possible substitutes for color. In terms of fermentation, traditional chicha employs diverse Saccharomyces and lactic-acid bacteria. Off Color Brewing blends in Lactobacillus-acidified, unhopped beer. Preferred yeast strains include Wyeast 3711 French Saison for peppery notes or Wyeast 3726 Farmhouse Ale for a bubblegum profile. Other options like Lachancea (WildBrew Philly Sour) or mixed pitches such as White Labs WLP4675 Farmhouse Sour Ale Yeast Blend are also viable. The goal is a pleasant tartness, not an overwhelming acidity, ensuring a balanced and authentic flavor experience.