Tropical Brewing
by Connor Harron
The craft brewing movement has migrated to Central America and the Caribbean. A growing number of small scale artisanal producers are building on the American Craft Brewing tradition by incorporating local spices and fruits into traditionally brewed ales. To distinguish themselves, from their temperate counterparts, they are adding a tropical flare and creating innovative flavor combinations. For example Domingo7’s Maracuyá Pale Ale (that’s Spanish for Passionfruit) in Costa Rica, Ocean Lab’s B.O.B. - Blood Orange Blonde in Puerto Rico and Lu Bru’s Maiz Azul (Blue Corn) Ale in Mexico all demonstrate how local producers are beginning to incorporate regional ingredients into local craft beer movements. This is surely a positive development and one that leads us to consider other ways we might be able to further highlight local and seasonal ingredients into craft beers.
These efforts will help to make brewing both more sustainable and position craft brewing as a vehicle for more thoroughly exploring terroir, which describes the potential for fermentation to be used as a method of expressing the unique environmental conditions of the places in which our ferments are produced. By using exclusively local ingredients as well as wild captured yeasts, we have the power to capture the unique flavors of seasons and regional differences that allow for near infinite variation and creativity to explore new combinations of flavors that are rooted in cultural tradition while simultaneously pushing the frontier of artesian brewing. As much as I love finding good craft beer in places like Mexico and Costa Rica, I constantly find myself asking if it really makes sense to be brewing beer with imported German Barley and Hops from the Pacific Northwest United States when there are such a plethora of sugar sources and bittering herbs available locally in nearly every corner of the globe. Could we instead develop beers using a hybridized process and create products that are truly local while still maintaining the key characteristics that make beer, beer?
Speaking of, have you ever asked yourself what it is that really makes a beer? It turns out, the answer really depends on who you ask and where you live. In the most general terms, beers are fermented from carbohydrate rich starches (typically grains such as barley) that first need to be enzymatically converted into simple sugars and extracted into a liquid malt before the substrate can be fermented to produce appreciable levels of alcohol. Wines and Ciders on the other hand, are fermented from fruits and simple sugars that can be fermented into alcohol with limited or no processing. In the case of beers, bittering herbs such as hops are commonly added to provide antimicrobial properties, improve shelf stability and add complex flavors to ferments. In the United States, it turns out that hops are not required in the production of beer and that there are many malt substitutes that are allowed in the production of beer, including “rice, grain of any kind, bran, glucose, sugar, and molasses (TTB Ruling, 2008).” This definition is actually quite liberating, and creates the opportunity to experiment with non-traditional malts and bittering herbs in ways that will promote creativity and improve the sustainability of the craft brewing market globally. This flexibility in malt production will be especially important given that recent climate models suggest that the regional distribution of barley production will become increasing restricted over the next 20 years (Nature, 2018).
In Costa Rica, we have been experimenting and finding repeated success using a wide range of local ingredients including banana, corn, rice, cacao beans, coffee and local cane sugar for producing malts. Corn and bananas, for example, both have long cultural traditions of being used in the creation of local beers. In Eastern Africa, Bananas have long been used to create malt for the production of banana beer (Urwaga or Mubisi as it is locally known). Bananas make for an interesting malt base because they fall into a relatively unique category of fruits that when ripe are rich in both simple sugars and complex carbohydrates that can be easily fermented into a strongly alcoholic brew while maintaining a mouthfeel that is remarkably similar to beer brewed from barley. When the ripe bananas are boiled for several hours, the sugars begin to caramelize, transforming the flavor of the malt into a sweet, neutral flavored base that remarkably, tastes very little of banana, making it an ideal substrate for mixing with bitter herbs or other local products such as coffee and chocolate that can be fermented into either an Ale or Stout like brew.
Conversely, in many parts of South America, but perhaps most notably in Peru, Maize has been used for centuries to produce a corn beer called Chicha. Unlike barley, which when sprouted produces a large concentration of Amylase Enzymes (the key types of enzymes needed to convert complex carbohydrates into fermentable sugars), to make a corn beer, these enzymes need to come from another source. The indigenous peoples of South America developed an ingenious solution to this challenge when they discovered that chewing the cooked corn would transform the starchy, carbohydrate rich grain into a sweet masa that could then be re-boiled in water and strained to create a fermentable Wort made purely from Maize. Although many foreigners cringe when they first learn about the process, for the Inca’s, it was a powerful community building practice that would bring people together to sit around the fire, alternating between sharing stories and laughter while chewing the cooked corn and then depositing all of the masa into a large pot. Although they almost assuredly could not have fully comprehended the transformations that were taking place, their solution was so ingenious because human saliva is packed full of the enzymes needed to break down the carbohydrates in corn into fermentable sugars. I experimented with the traditional process a couple years ago, and I have to admit it was a powerful community building process that for me, took the idea of collective fermentation to a whole other level. Talk about terroir!
The problem with the traditional process is that it is incredibly labor intensive. If you are lucky, like me, you might be able to convince your friends to help you chew a few pounds of corn once or twice for the novelty of the experience, but you are likely to be hard pressed to find a consistent source of labor to chew through the many pounds of corn you will need to produce even a few gallons of Peruvian style Chicha. Fortunately, today we have access to many sources of amylase besides our saliva. As it turns out, ripe bananas (and in particular, ripe banana peels), contain a very high concentration of the same amylase enzymes needed to convert the starches in Maize into fermentable sugars. If you think about it, this actually makes a lot of sense. Unripened green bananas and plantains are a very starchy staple food crop that is used culinarily in a similar fashion to potatoes. As the skin yellows and the banana ripens however, the banana naturally transforms those carbohydrates into simple sugars that make dessert bananas so pleasant to eat directly out of hand.
Due to the high concentration of amylase enzymes present in ripe banana peels, they can be dehydrated and pulverized into an enzyme rich powder that can be mixed with ground maize and water and then mashed similarly to a barley based beer between 140-160 F for 2-24 hours (depending on the ratio of corn to powdered banana peels used) before being strained and boiled to make a fermentable wort. You’ll need to taste the Mash or use iodine strips to determine when the conversion has been completed. There are actually lots of fruits and vegetables that are rich in amylase enzymes. Sweet potato, for example, has such a high concentration of these enzymes that its peel is often used in the commercial production of Amylase.
Alternatively, instead of using the enzymes present in another product, it is also possible to ferment grains with certain types of molds that consume starches and in turn naturally produce the enzymes needed to convert the grains of carbohydrates into fermentable sugars. In Japan for example, Aspergillus Oryzae (or Koji as it is better known), is a humble yet miraculous mold that has been grown on rice for millennia in order to sweeten the rice and make Sake. It is also the key ingredient for making naturally brewed Soy Sauce or fermenting Miso due to the rich diversity of enzymes Koji produces that not only sweeten carbohydrate rich foods, but also break down proteins into amino acids that are the basis for savory foods and the flavor of umami. Due to these impressive properties, koji has now made it’s way out of Japan is slowly become increasingly familiar around the globe. This is assuredly a wonderful thing, because it has now been well established that Koji can be grown on a variety of substrates and virtually any grain, including rice, barley and corn, making it an ideal candidate for assisting in the brewing process anywhere on Earth.
To further explore local flavors and novel combinations, while boiling our worts we have been experimenting with using a variety of local bittering herbs and teas to add complex flavors to our beers, including ginger, turmeric, lemongrass, vanilla and many others. During either primary or secondary fermentations, we use nylon mesh bags weighed down with boiled volcanic rocks to infuse fresh fruit from the farm such as Pineapple, Soursop, Starfruit, or freshly roasted Cacao Nibs, just to name a few examples. Finally, by fermenting our beers with mixed cultures, wild captured yeasts and/or locally adapted strains, we have been able to produce ales with several layers of harmonious flavors, which provide depth and complexity that is only possible to achieve with mixed culture fermentation.
I would not have believed what a powerful role yeast and bacteria play in the creation of complex beers and wines when I first started brewing over a decade ago. Now however, I have learned first hand just what a difference the cultures we use can make. The experience of trialing yeast captured off of different fruits and flowers has led me to encounter flavors I never would have dreamed possible. Some have certainly been on the far side of the funky extreme, including cultures that produce the dreaded odor of sweaty feet or burnt rubber. This however, is exactly the reason for small scale trials rather than placing our faith in large scale spontaneous fermentation. Once you discover the joy of fermenting a simple malt of dissolved sugar or Dry Malt Extract with wild yeast and tasting apples, pears, or other citrus fruits magically appear in the finished product, I believe that like me, you will never want to use a commercialized yeast strain on it’s own again.
I believe that by drawing from the richness of our cultural traditions around the world, we have the potential to greatly expand the breadth of our palates and to more intimately link our brews to the time and place in which they were crafted. The craft brewing revolution is still in its infancy and if I am to have a part of to play in it’s development, then Ginger Hibiscus Sake Hybrids, Banana Coffee Stouts, and Mayan Chocolate Ales will be just the tip of the iceberg.
If you would like our simple Hooch recipe, read our blog article with step by step instructions. If you want to learn more about the wild world of fermentation consider joining us for our year long apprenticeship where apprentices go deep into advanced fermentation techniques.