Water & Soil

How cold can a beer get in Mexico City when the sun is shining? Very cold, because the city sits at around 2,240 meters above sea level in a highland valley, and Toluca towers roughly another 400 meters above that, at about 2,600 meters. The days are bright and mild, the nights cool, and rain falls from June into autumn.

Water behaves differently at this altitude too. Because air pressure is lower, it boils at around 92 degrees instead of 100. For boiling the wort, the sugar solution made from malt that later ferments into beer, this is a detail brewers have to account for.

The capital sits on the bed of a former lake basin. Lake Texcoco once lay here, and the soft ground still shapes where the city draws its water from today: wells beneath the surface and tributaries from far away.

How hard or soft the water in the tanks ends up being depends on treatment, since nearly every large brewery today adjusts its water. They strip out minerals or add salts until it suits the desired style. So the terroir barely determines anymore whether a lager tastes crisp and light or dark and round.

The real chill happens in the equipment: in the brewery's lagering tanks, and later in the cantina's cooler, where the bottle emerges ice-cold.