My 4 Bs of Great Coffee – B(4) is for Brew
In my final installment of the 4 Bs for a great cup of coffee, I go over the perfect brew. Depending on how one is brewing, these factors can change because of the underlying science involved in extracting that coffee flavor we are familiar with.
In review, I have covered Beans, Burn, and Burr. The final step to bring it all together is how you brew. Espresso, for example, the flavor is extracted by emulsification using high temperature water and pressure through a powdery grind of beans. In this article I’ll focus on standard pour-over and drip brewers.
The ideal temperature for coffee flavor extraction is 200º, give or take 5º. Any lower and you have under-extraction; higher and you have over-extraction. This will lead to either weak or bitter coffee, respectively.
Time also plays a factor. How long is this coffee exposed to this water? Too short or too long also leads to the same result – over or under extraction. At 200º and a medium grind, the perfect amount of time is 4 minutes.
All these factors play hand-in-hand in an almost slide-rule type way. Keep the temperature the same but increase the grind size? It will take longer to extract the coffee or allow more brew time than 4 minutes. Same thing with a higher temperature water. Using water closer to boiling? Larger grind.
I’ve never seen a Mr. Coffee type drip machine get close to the ideal temperature of 200º. Every one I have measured clocks in at the 180s. But that’s OK because those suckers can take up to 20 minutes of water running through your grounds, compensating for what would have been an under-extracted brew. It’s called a drip brew because that’s what the machine is doing. The water is coming out in drips. Drip by glorious drip.
Personally, I prefer a pour-over. It varies from the drip in the amount of water entering the brew basket at once. When making a cup or pot of pour over, you generally heat water up just to below boiling and you pour the water over a round brew basket in concentric circles going from the outside to the inside, back to the outside. This keeps the grounds from stagnating. The grounds are constantly moving around, not collecting on the bottom slowing down the time it takes for the water to leave the brew basket and enter your cup or pot.
This is why I prefer Bunn coffee brewers. Technically, they are classified as a pour-over brewer because thats exactly what they do. Have you ever watched these things at a restaurant brew the coffee? That shit is pouring into that pot. No drips there. And guess what? Bunn designed it to complete the brew cycle in 4 minutes. How did they overcome the concentric circles? By forcing the water out through a 5-hole shower head. This keeps the coffee grounds circulating within the brew basket. This is also why the Bunn home brewers have to use a much taller filter than your traditional coffee filter. Otherwise your coffee comes in so fast it would eventually overflow the filter getting coffee grounds in your cup.
Bunns (and Bunn knock-offs such as Avantco) also contain a hot-water heater/tank. The first time set up of this pot one must pour in a couple pots’ worth of water. The boiler will heat the water up to the set temperature and hold it there. These coffee brewers simply stay on all the time providing instant hot water when needed. When it’s time for a pot of coffee a fresh pot of water is poured in, forcing out a pot of already heated water through the brew basket.