It powered the legions that marched from Hadrian’s Wall to the Euphrates. It quenched gladiators between bouts and was offered to Jesus on the cross. For centuries, it was the daily drink of the Roman soldier, the labourer, even emperors when they wanted to “drink like the men.” Its name was posca – a sharp, vinegary, lightly salted brew made from sour wine diluted with water. Cheap, antimicrobial, and astonishingly effective at keeping dehydration at bay, posca was the original hypertonic hydration drink.

Fast-forward two millennia, and posca is back – sparkling, sugar-free, canned, and proudly Australian. Launched in October 2024 by comedian, SAS Australia winner, and confessed “health and fitness nut” Merrick Watts, Posca Hydrate is the first commercial revival of this ancient elixir, re-engineered with modern science and zero stimulants.

From Legionary Rations to Lockdown Kitchen

The story begins in the depths of the 2021 lockdown. Watts, already deep into wine studies for his sommelier qualification, was researching ancient Georgian winemaking when he stumbled across references to posca.

“I came across the original recipe and its fascinating stories, buried in the (online) history books,” Watts says. “Pliny the Elder, Cato the Elder, even the crucifixion – this drink was everywhere in Rome. Soldiers carried it because vinegar purified dodgy water and the salt-electrolyte mix kept them marching. I thought, ‘Why has no one brought this back?’”

Armed with little more than curiosity and a SodaStream, Watts started experimenting. Early batches were rough: “most of them were just horrific”, but the results were undeniable. After deliberately dehydrating himself and running 21 km with a 27 kg pack (mimicking special-forces selection), he rehydrated solely on his homemade posca. “I felt better than I had any right to. Then I carbonated it, and it was a total game-changer; the bubbles seemed to unlock the electrolytes even faster.”

Three years of obsessive refinement followed. Watts teamed up with Ed Stening, ex-Lion executive and drinks industry veteran, who tasted the liquid and decided to quit his corporate job to co-found the company.

“I’ve spent decades looking for truly innovative liquids,” Stening recalls. “When Merrick walked in with these little sample bottles, I was blown away. Zero sugar, all natural, prebiotic fibre, four electrolytes, and a 2,000-year-old story? I left my career to work with Merrick on this.”

Science Meets Legionary Wisdom

Posca Hydrate is built on red wine vinegar, five times richer in antioxidants than apple cider vinegar, blended with sodium, potassium, magnesium, and calcium, plus prebiotic insulin for gut health. The result is a hypertonic drink with a higher solute concentration than blood plasma, meaning electrolytes are absorbed faster than in water or isotonic sports drinks.

Posca Hydrate is available in three flavours – Grape, Yuzu (citrus), and Pineapple in 330 ml can, delivering:

• Zero sugar, zero stimulants, zero crash
• 320–350 mg electrolytes per can
• Bold, bright aromatics and a refreshing acidic snap
• A crisp, sessionable sparkle that finishes clean and dry

Watts himself no longer takes magnesium supplements. “I used to get eye twitches and muscle cramps constantly. Since we canned this stuff, they’re gone. I just drink Posca.”

Ancient Drink, Modern Mission

The historical parallels are striking. Roman soldiers drank posca to prevent cramps and stay sharp on long marches; modern bartenders, gym-goers, and shift workers are reaching for it for exactly the same reasons.

“If we just became the bartender’s best friend, that would be a massive legacy,” says Stening, who once pulled 3AM closes surviving on full-strength Coke. “Hospitality shifts are brutal. This keeps you hydrated and clear-headed without the sugar rollercoaster.”

The brand has already secured listings in independent liquor stores, gyms, and premium convenience channels. Early 2026 will see a major push into the UAE (the first year of the Australia–UAE free trade agreement) with plans to place Posca Hydrate in high-end resorts alongside sports and wellness offerings.