Rejoice, summer is coming! Daylight savings is upon us, jeans are being shunned in preference for shorts and lilly white bodies are starting to tentatively dip themselves in the ocean once more as the days begin to warm up. With the warmer weather comes a demand for icy cold refreshment, and coffee is by no means excluded from the list of options of drinks to cool you down on those hot summer days. Cold drip, iced latte, cold brew, chilled filter, iced black, it’s just coffee over ice right? Well not quite, there are a couple of key differences to brewing coffee to be served cold, and depending on which one you choose it will have a big impact on flavour.
How water temperature affects brewing.
Ever wondered why cold brew coffee tastes so different to coffee that is brewed hot then chilled? Cold brew coffees taste considerably less acidic and lack complexity compared to hot brewed coffee. This is down to hot water being a much more efficient solvent, able to quickly extract certain compounds like sugars, acids, lipids and caffeine, which all play a part in the resulting flavour of your cup. Cold water is less efficient, and extracts certain compounds differently, particularly acids, resulting in much longer brew times (hours compared to minutes) and a completely different flavour profile.
Cold water brewing.
Immersion brewing is the most common method used and the simplest. Cold water and coffee are added to a vessel and left in the fridge anywhere from 4 to 24 hours, the resulting brew is a low acid, concentrate that can be stored in the fridge for a week or so. The concentrate can be diluted or drunk neat, or used as the base for other drinks. Cold brew has seen an explosion in popularity over the last couple of years, its mellow and sweet flavour profile makes it very approachable, particularly to those who find coffee intense or strong. The downside to this method of brewing is it tends to give all coffees the same flavour profile, whether it is a wonderfully floral Ethiopian or a juicy complex Colombian, the resulting brew tends to taste similar, round and sweet, but lacking complexity and character.
Hot water brewing, flash chilling.
Brewing with hot water directly over ice allows you to extract those wonderful flavour compounds that give the coffee it’s complexity, character, and aroma and flash chilling means they are locked in the cup giving the brew a crisp, sweet, clean profile. It is important to remember to adjust your brew ratio when using this method as the ice in the carafe is going to dilute the brew as it melts. If you were to use your standard brew ratio you will end up with a weak batch of cold coffee, you’ll need to use less water and grind finer to compensate for the ice. Don’t forget that you are then going to serve the coffee over ice as well resulting in more dilution, these are important things to take into consideration when working out your brew recipe for brewing over ice. The brew will last for 24 hours in the fridge, but after that the process of oxidation will begin to affect the taste, so be careful to brew just what you need for the day, stale coffee never tastes good.
Chill out man.
Good quality coffees have complex acidity and sweetness, and these characteristics should be showcased, that’s why brewing hot and rapidly chilling is seen as the preferred method for many, it’s fresh and fast and highlights the origin and quality of the coffee. Cold brew has the benefit of being able to be brewed in large batches and have a longer shelf life, the concentrate is also versatile and can be used in different ways, however its downfall is its lack of complexity and narrow flavour profile and the length of time needed to brew a batch. With summer fast approaching now is the time to experiment and lock in your cold coffee offerings, if you want to highlight the epic flavour profiles of different origins then we recommend brewing hot and chilling rapidly, keeping it fresh and keeping your customers stoked!
Stay chill, Stay tasty!