Guarapo – guarapo de caña or jugo de caña in Spanish-speaking Latin America, caldo de cana or garapa in Brazil – is the juice of freshly pressed sugarcane. Street vendors crush the peeled stalks through a roller press and serve it over ice, often with lime. Most of it is drunk fresh, but left to stand, the sugary juice begins to ferment within hours from the yeasts and bacteria it picks up from the cane and the press, turning lightly fizzy, less sweet and tart. In some countries the word guarapo is also used for other homemade fermented drinks; this page is about cane juice.
Fresh or Fermented
Fermented guarapo is a wild fermentation, and we found no study measuring how its microbes, acidity or alcohol change hour by hour, so we don’t give a strength or a list of species. What’s certain is that a sugar-rich juice left at tropical temperatures ferments fast: yeasts make carbon dioxide and some alcohol, and given more time, acetic acid bacteria can turn it vinegary. Treat any guarapo left for more than a few hours as a drink that may contain alcohol, and keep it away from children.
Raw Cane Juice Safety
Guarapo is a raw, unpasteurized juice. The US Food and Drug Administration warns that untreated juices can cause serious illness in children, older adults, pregnant women and people with weakened immune systems, and notes that juice sold by the glass – at markets, roadside stands and juice bars – carries no warning label (FDA). Sugarcane juice also has a particular history in Brazil: together with açaí pulp, it has been linked to outbreaks of acute Chagas disease, a parasitic infection that can be passed on when the insects that carry it are crushed into food during processing (Mattos et al., 2017). That’s why clean, peeled cane, a clean press and clean hands matter as much as freshness.
Making It at Home
You need fresh sugarcane stalks (sold in Latin American, Caribbean, African and Asian groceries) and a press, a heavy-duty juicer, or a strong blender and a cloth to strain through – or bottled juice that lists only sugarcane. Preservatives such as potassium sorbate or sodium benzoate will stop it fermenting. Peel and rinse the cane, press it, and either drink the juice at once or ferment it briefly, loosely covered, then chill it. Sugarcane wine is a different, longer project: see Ilocano basi, where tree bark keeps the ferment clean. For other quick fruit and sugar ferments, try Mexican tepache or water kefir.