..drinking too much coffee!

For the last week or so, I’ve been trying to come up with a new method for brewing with a cafetiere. It all started when I was testing our new thermal cafetieres for a previous post. I notice something that is really obvious, but hadn’t crossed my mind before: when you add water to a cafetiere, the cafetiere immediately sucks some of the temperature out of the water.

Even if you pre-heat a cafetiere, its temperature is still lower than the water in your kettle (which of course you’ve left to cool down a bit after boiling). So as soon as you pour the water into the cafetiere, it absorbs heat away from the water until they’re both at the same temperature. As cafetieres are usually made from conductive materials (glass or stainless steel) this heat sync occurs within seconds of pouring water into it.

This leaves a conundrum. The ideal temperature range for brewing coffee is between 90-95°C. Higher than 95°C, scolds the coffee, destroying delicate aromas and imparting bitter flavours. Lower than 90°C produces an under-extracted brew, tasting weak and possibly sour. If we leave the water in the kettle to cool to 95°C and then add it to the cafetiere, after heat sync the temperature could be as low at 90-91°C. This will steadily drop through out the brewing process, so the time the coffee is actually brewing within the optimum temperature range is quite short.

The alternative would be to allow the kettle water to cool less, say only to 98°C, so after heat sync the temperature would be around 94-95°C. However, what’s waiting to meet the 98°C water at the bottom of the cafetiere? The coffee! Until heat sync occurs the coffee is going to be in contact with water that’s too hotter. Even if this exposure is only for a few seconds, delicate aromas could still be lost.

Eureka Moment?

The aim of the new brewing method is to solve this problem. To come up with a technique which keeps the brew temperature in the optimum range for longer and so theoretically improve the taste of the coffee.

Now as you know the standard way to brew in a cafetiere is to add coffee first then water. My idea is to do things the other way round; add water then coffee. This way I can pour boiling water into the cafetiere and simply wait for it to cool to below 95°C before introducing the coffee. As the cafetiere and water are already in sync, there’s no sudden dip in temperature.

I was hoping in this post to actually write about the brew method. But I’m having a problem: in the standard method when you pour water over the coffee grounds you’re agitating them, which helps the extraction process. In the new method I need to recreate this agitation and do it in a way that’s easily repeatable.

Unfortunately, I am still struggling to find a technique which gives consistent results. At the moment after adding the coffee to the water I fold it in, like when you bake a cake. The problem is that when the coffee starts blooming, the grounds are pushed up out of the water (probably due to the CO₂ they release). So I then have to break the crust to reintroduce the grounds to the water. This additional intervention is causing the inconsistency.

I will persevere though. Hopefully after the weekend I will have this technique nailed and be able to put it to the taste test.

Tags: cafetiere

This entry was posted on Thursday, June 3rd, 2010 at 7:04 pm and is filed under Brewing Methods. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.