Ever wondered how hot the water is in a coffee maker? I first wondered this back when the woman sued McDonald’s for serving coffee that was too hot. This was but a passing thought in an adolescent mind but since then the question became important to me because it matters a great deal in making good coffee.
Why does it matter you may ask?
It matters because the actual coffee flavor is extracted from grind better at higher temperatures. I’m not a scientist but I trust those that have done the research and they say that the optimal temperature for hot water in a coffee pot is between 195-200 degrees or just a little under boiling.
The reason for this is that lower temperature water doesn’t get the full favor out of the grind in a standard drip coffee pot. That’s why your home brew is frequently more bitter than the coffee you get at your local Starbucks.
Unfortunately this isn’t so well known and many people simply don’t care. That’s why in many lower end coffee pots the heating element doesn’t get the water hot enough to the best flavor possible.
The result, these cheaper coffee pots just don’t get the water as hot.
I ran a test on an older coffee machine of mine and put cold tap water into the reservoir. Using no grind I just hit start. The first 2 cups to come out of the pot I measured with a meat thermometer to be around 140 degrees! That’s terribly low.
The second 2 cups came out at around 160 followed by 170 and the last 2 cups came out at around 180 degrees. It never got anywhere close to 200.
I found better results by running hot water from the tap into the chamber and then hitting the brew button. The first bit of water to hit the carafe was coming in around 165 degrees or so and that bit might have gotten to 185 if I’m being generous.
Long story short – the better your coffee maker is and the hotter the water is in the reservoir before brewing the hotter the water will be when it gets to the pot. A cheap or poorly performing coffee maker may heat a full pot of coffee up to around 165 or so in my case but a better machine will get it up to 190 or more.
Keep in mind that water boils at 212 degrees so your water shouldn’t actually get that high. In fact it’s hard to get it up much further than 200 as the water closest to the heating element turns to steam while the remainder of the water in the chamber or vessel stays a bit lower – say 200 or so.
Also, once hot water flows through coffee grind the temperature is inevitably going to drop. If you are interested in the water temperature after it flows through the grind then expect the final pot of coffee to be around 190 or so even in the best coffee makers.