Evaporation. Solubility. Insulation. And why beer-battered fish and chips are yummier.
Beer-battered fish and chips just seem to taste yummier. The fish inside is usually moist and tender while the crust is golden, light and crispy. What is the science behind this: Why is batter made with beer better than batter made only with water?
There are five reasons.First, beer contains both alcohol and water. Alcohol has a lower boiling temperature (78.5°C/173°F), so when we deep fry the beer-battered fish, the alcohol evaporates quickly. Our sense of smell is stimulated by the resultant volatile compounds, giving us the sensation that something yummy is being cooked.
These volatile compounds also include compounds that might have been soluble in alcohol but not water, thus adding to the aroma we smell.
At the same time, the remaining water evaporates more quickly than if the batter was made only with water, simply because there is less water in a beer batter. The beer can thus reach the Maillard reaction temperatures faster. The crust turns golden brown very soon after, and the risks of overcooking the outside and inside minimized.
The fourth reason is that alcohol contains a lot of carbon dioxide. This gas is highly soluble, but once the temperature is raised, its solubility is drastically reduced and it rises up through the beer batter as bubbles. The bubbles stretch the batter (not unlike what happens in dough when we bake bread or fry donuts), and make the crust of beer-battered fish fluffier.
The carbon dioxide bubbles also help the batter to be a good insulator, i.e. it does not conduct heat well (read all about conduction in the 1-Minute NomNom “Pleased to heat you!“). As a result, despite the high temperature of the oil, heat is only conducted into the fish slowly. This further reduces the risks of overcooking, and the fish stays moist and tender (especially since fish cooks faster than other meats – see the 1-Minute NomNom “Fast food”).
Like this? I go better with beer too, so like me to discover more! All you need is a minute a day to explore the world’s marvels through the phenomenon of food!
photos: in order – depositphotos/subbotina; jag_cz; neillangan; nupix