Casey Brewing & Blending's Undertone - Marionberry & Madagascar Vanilla

Casey Brewing & Blending's Undertone - Marionberry & Madagascar Vanilla is a limited-release fruited farmhouse ale that showcases the Colorado brewery's signature mixed-fermentation approach and meticulous ingredient sourcing. The base is Undertone, an oat-forward farmhouse ale fermented with a blend of wild yeasts and lactic bacteria, then conditioned on marionberries—a dark, tangy Pacific Northwest blackberry hybrid—and premium Madagascar vanilla beans. The result is a tart, jammy, bottle-conditioned wild ale that balances bramble-fruit acidity with creamy floral sweetness, typically clocking in around six to seven percent ABV. Casey's reputation for precise blending and Colorado terroir expression has made their Preserves fruited line a benchmark for the style, and this marionberry-vanilla variant regularly scores above four stars on Untappd for its elegance and drinkability. Casey Brewing & Blending operates outside Denver in Glenwood Springs, Colorado, where founder Troy Casey has built a cult following for wild ales that emphasize Colorado ingredients and traditional farmhouse techniques. The Undertone base begins with a grist heavy in oats, which lend a silky mouthfeel and bright citrus notes, then undergoes mixed fermentation with house-cultured wild yeasts and lactic bacteria in oak. After primary fermentation, the beer is conditioned on whole marionberries and split Madagascar vanilla beans—both chosen for their intensity and complexity—then bottle-conditioned to develop subtle carbonation and evolving funk over time. The brewery releases these 750ml bombers in small batches through their membership program and select bottle shops, treating each variant as a seasonal snapshot of fruit at peak ripeness. The flavor opens with bright, tangy marionberry—jammy dark fruit, blackberry pie tartness, and a hint of bramble—softened immediately by rich, creamy vanilla that adds floral depth and a velvety texture without turning sweet. Underneath, the oat base contributes gentle citrus zest and a rustic yeast character, while the wild fermentation brings a whisper of barnyard funk and a crisp, refreshing finish. It's tart but never aggressively sour, with layers that unfold as the beer warms from fridge to cellar temperature. Serve it chilled in a tulip glass alongside a cheese board with aged cheddar and fig jam, or pair it with lemon panna cotta to echo the vanilla and fruit interplay. Fans of farmhouse ales, fruited sours, and Lambic-style beers will find this an approachable yet complex introduction to wild fermentation, and it cellars well if you want to explore how the funk develops over a year or two. Casey Brewing & Blending's Undertone - Marionberry & Madagascar Vanilla is available now for pickup at our Lincoln Park bottle shop at 1128 W Armitage Ave, local Chicago delivery, or nationwide shipping.