The Science of Cold Extraction
Traditional iced tea is hot tea flash-chilled over ice—locking in bitter tannins and requiring spoonfuls of sugar. Evy Tea never touches boiling water. Here is why cold brewing changes everything.
Cold Brew Tea vs. Traditional Flash-Chilled Iced Tea
How thermal extraction alters tea chemistry at the molecular level
How We Cold Brew at Our Boston Brewery
Whole-Leaf Single Origin Selection
We never use tea dust, powders, or industrial fannings. Instead, we select whole, intact loose leaves grown at high altitudes across Japan, Taiwan, India, and Sri Lanka. Intact leaf structures prevent harsh astringency during long cold immersion.
Triple-Filtered Cold Spring Water
Tea is 99% water. We filter our brewing water through carbon block and sub-micron particulate filtration to eliminate chlorine, unwanted minerality, and heavy metals while keeping balanced mineral TDS that enhances delicate tea aromatics.
16 to 24-Hour Cold Extraction at 38°F
Submerged in stainless steel cold brew tanks, the whole leaves steep in circulating 38°F water for up to 24 hours. Because cold water cannot easily dissolve heavy bitter tannins or tannic acids, it selectively extracts only the amino acids (L-theanine), natural sweet sugars, and bright top-note florals.
Double Micro-Filtration & Nitro Infusion
Once optimal extraction is reached, we double micro-filter the liquid to remove all leaf fines without stripping beneficial catechins. For our on-tap kegs, we flush the draft lines with pure food-grade nitrogen to generate a cascading creamy mouthfeel and velvety head.
The Magic of Nitrogenated Cold Brew Tea
At Tea Bar by Evy, we pioneered nitrogen-dosed cold brew tea kegs. Micro-bubbles of nitrogen gas dissolve under high pressure, pouring with a creamy Guinness-like cascading effect and a dense head of velvety microfoam—without adding a single drop of dairy or sugar.