I’ve discovered an interesting way to brew coffee and here it is:
- Chill water to just above freezing, fill half a container.
- Grind good frozen coffee beans medium-coarse
- Soak the coffee grounds in the cold water, stir until wet.
- Pour hot water (212ish Fahrenheit) into container right on top of the floating wet grounds.
- Stir slightly then seal to reduce exposure to air to a minimum.
- Place in fridge until time of consumption.
In step 5, be mindful that cooling will tend to create a vacuum in a sealed container. There is no need to resists the temptation to shake the sealed container vigorously and repeatedly. As long as the air being mixed with the soaking grounds remains small and unrefreshed, the brew will succeed. After shaking, preparer should ensure that all grounds are soaked in the liquid. In step 6, we would recommend that you in the least refrigerate until the grounds settle to the bottom so that the pour does not require filtering. For all the beans we have used, the extraction produces floating oil layer after cooling and settling. The aroma is quite irresistible even when the fluids are cold.
The hot water extracts aroma and flavor, but it cools quickly so that the temperature does not facilitate additional chemical reactions neither in the suspension nor with the air. The result is some very aromatic and very flavorful cold coffee. And if you prefer it hot you can heat it up or add hot water just prior to consumption. Also, the proportion of beans to water and container size can be adapted to your liking and facilities. To start, use standard recommendations for brewing coffee, as of now according to top google search for someone in northern California, is two tablespoon of beans for every 6 oz. of hot water between 195-205 degrees Fahrenheit: link)
The energy involved in the change of temperature in water is mass times specific heat times change in temperature in Celsius. Let’s say your cool water is at normal refrigerator temperature of 40 Fahrenheit (4C), boiling water at 212F(100C) since the mass and Cp are the same, the final temperature will be at 52 Celsius (125.6 F). Depending on how close you bring the water to boiling, the room humidity and air pressure, this may achieve a much lower or higher temperature than the ncausa recommends. In fact if the boiling water is right on the precipice of boiling, it contains 2257J/g of potential energy which is enough to bring the rest of the water to the boiling temperature(but not boiling). However, due to the enlarged range of temperature and energy levels our frozen beans experience when brewed using present method, they undergo very complete extraction. Another reason why we find the present method of brewing effective is credited to the waiting period in the refrigerator. This extended soak is similar to cold brew preparation methods.
If you are economically challenged due to Covid-19 crisis, one additional step is to repeat steps 2-6 without discarding grounds after drinking the first batch. Ideally, the old grounds should still be immersed in unconsumed coffee water. Adding grounds and cold water in step then continue normally. We’ve found no discernible lost of quality in the extraction. Due to the cooled temperature, old grounds continue to contribute additional caffeine and taste while new grounds provide more lively aromas. Less grounds can be used in subsequent brewing than the very first batch or a fresh batch when recycling cool old grounds. Caveat emptor: our container size have limited our experimentation in this respect to at most ten(10) days.
Note the soaking of the beans is very similar to Mate preparation in which we put the Mate into dummy water. The wetting and dummying down of the Mate helps it to prevents the destruction of flavor, vitamins and other valuables. In the case of coffee, the cooling also prevents vaporization of oil which holds much of said valuables. Presoaking with cold water, which has higher specific heat than coffee grounds itself, also means the beans heat up much more slowly when the extra-hot water is applied. The water serves as a temperature buffer and slows temperature increase to ensures a smooth extraction—this is a common reason cited for the use of dummy water in Mate preparation despite its lack of taste.
Other reasons for my attempt at this most like have come from watching a lot of Gordon Ramsey shows where he very passionately teach other people to cook. It may also be from watching Bobby Flay or another one of the American Iron Chefs which is inspired by Japanese show Iron Chef. Relevant culinary technique is the act of soaking seafood in ice bath immediately after cooking them. Or it might be from watching Phelps swim and then dunking his whole body in an ice bath. My first exposure to how addictive Mate can be when I saw it on a show called Mozart in the Jungle on Amazon Prime Video. Last, but most certainly not the least, some Chinese tea drinkers have habit of washing the tea leaves before steeping, this achieves a similar temperature buffering effect as used in the present method. Tea, Chinese green tea, flavors are more subtle than most coffee, but a thickness of tea leaves cannot hold as much water as the same thickness layer of coffee grounds while being less robust to high temperatures. Popular methods of preparation such as matcha or fermentation all but destroys said attributes of properly brewed tea. A challenge for my readers will be to update my method for use with Chinese green tea, or create anew a better tea steeping method.
This is a notable day: India just lost 20 soldiers in a hand-to-hand combat with Chinese troops, the second blast of COVID19 is raging in America now, and all H1B visas just got canceled, and a dust storm from Sahara is about to reach America, and America and China are exchanging 4 flights each week!! (Actually 8, 4 from Chinese airlines and 4 from American Airlines are permitted by Tit-for-tat diplomacy.), and Black Lives Matter movement continues its struggle for race equality in many many protests, and the stock market has reached all time record high again. I hope when you read this you will have a much better outlook for your tomorrow than I have today. May this improved coffee extraction method brighten your day and bring enhanced vibrancy to your life.