Troubleshooting French Press Coffee

This article is an expansion of a troubleshooting table inside the French Press Tutorial. I’ve brewed a lot of coffee in my French Press. Along the way I’ve developed a checklist of steps to take to improve the taste. There are variables that are easy to correct and some that take a little tweaking.

Before you start tweaking, its important to get the basics correct. The steps listed below should be followed in sequence. There is no point in tweaking the grind if your water quality is poor. Also I use the terms press pot and French press interchangeably.

Water Quality

There are several articles on this site that cover water quality. I have a simple rule to measure water quality. Drink the water by itself. Does it taste good? If the water tastes bad on it’s own, then your coffee will probably end up tasting bad as well. Seek out a good water source before you start to brew your coffee.

Bodum Chambord Coffee Press
Bodum Chambord Coffee Press (Amazon USA)

Brewing Temperature

When brewing French Press coffee, you want the temperature to be just off a boil. This equates to 195-205 F or 90.5-96.1 C. Once your water comes to a boil, remove it from the heat source and let it sit for 30 seconds. The 30 second wait gives the water just enough time to drop to the perfect temperature.

But what about office workers that are using the hot water dispenser to make their coffee? The temperature could be too hot, too cool or the water could taste flat. You could buy a thermometer to test the temperature. Personally I advise buying a cordless electric kettle and bringing that into the office. I have heard stories of employees microwaving the water used for brewing. This could be unsafe. From Superheating and microwave ovens :

There have been many reports of injury to people using microwave ovens to heat water to make hot drinks. Water heated in a microwave oven may be superheated and when objects (e.g. a spoon) or granulated materials (e.g. instant coffee) are put into it, the water may boil very vigorously or even appear to explode out of the container. The vigorously ejected boiling water can cause serious burns. Sometimes even the act of taking the container out of the oven and or putting it on the bench can cause the boiling.

An electric kettle is cheap. To eliminate brewing temperature as a cause for bitter coffee, get one. They even have electric kettles now, like the Bonavita, that let you program in the exact temperature you want. This is good for coffee and excellent for tea.

Bonavita 1-Liter Variable Temperature Digital Electric Gooseneck Kettle
Bonavita 1-Liter Variable Temperature Digital Electric Gooseneck Kettle (AMAZON USA)

Fresh Coffee

Coffee is a perishable item. As it ages, it loses flavor. How much flavor loss is acceptable is up to you. I used to only drink coffee that was less than 10 days old, but in recent years I’ve been surprised by some lighter roasted coffee that still tastes very good three weeks after roast. A general rule is the darker the coffee is roasted, the shorter the window of freshness will be. A light Scandinavian roast might stay flavorful for more than three weeks, whereas a dark French roast could begin to go stale less than 1 week after roast.

If you don’t roast your own coffee, then look for a roasted date on the bag of coffee before purchasing. Grocery stores are notorious for putting the stale coffee in front of the fresh bags. Just dig deeper into the pile looking for a fresher date. If a roaster doesn’t put a roasted date on the bag, I assume the they are hiding something and the coffee is stale. As you attempt to make a perfect cup of French Press coffee, you’ll want to eliminate as many variables as possible. Having a high quality fresh coffee to work with will increases your odds of success.

Grind Size

A press pot uses a coarser grind than drip coffee. If the grind is too fine the coffee will taste bitter. If the grind is too coarse the coffee could taste weak. When it comes to grinding, a coffee drinker has two choices. Have it ground at the time of purchase using a commercial grade grinder or grind it yourself. Having it ground at the roaster or grocery store will guarantee that the size is perfect, however the flavor compound in the coffee will start breaking down immediately. The result is you’ll be trading a bitter coffee for a stale coffee. In other words, you’ll want to get a grinder. Once you have your own grinder, it takes just a little practice to get the perfect grind.

French Press Grind by US nickel
Coarse Coffee Grind most commonly used for French Press coffee. Some coffee drinkers will prefer it a little finer, but this is a good starting point.

Steep Time

The most common steep time recommended for French Press coffee is 4 minutes. I have talked with many coffee professionals and the range they use varies from 3 to 6 minutes. After brewing thousands of pots of press pot coffee, my recommended time is 3.5 minutes. In my opinion, the coffee tastes brighter and more flavorful at the lower end.

I’ve found that the body takes over the flavor the longer the steep time. I’m in the minority opinion on the topic, so this will take your own experimenting. Another opinion is to adjust steeping time based upon the actual coffee. If you want to highlight the bright flavors, do a 3.5 minutes steep. If your goal is to develop a richer body, add an extra minute.

Dosage

Getting the dosage correct is the last step. The reason it is the last step is because the other steps tend to have more fixed rules. Although there is recommended dosage, dosage is in the end a personal choice. The debates over water quality, coffee freshness, grind size and brewing temperature are over. Steep time has a sliding window of +/- 30 seconds. So the only real variable left is dosage.

The reason dosage can be tricky is that people new to press pot coffee will often perceive the taste as “too strong”. Press pot coffee is supposed to taste richer. If that richness is comes off as being “too strong” then those new to press pot coffee may experiment with a lower dosage and then over time gradually move the dosage in line with standard recommendations. But you don’t want to go too low or the coffee will taste bitter.

What is the dose? According to Bodum, the most popular manufacturer of the French Press coffee maker, for each 4 oz. cup (1.25 deciliter), put 1 rounded tablespoon of coarse ground coffee into the pot. My advice is to start with this dose and then adjust up or down.

Another dosage option is to weigh the beans using a kitchen scale. The common ratios used are covered in the original tutorial.

brew ratio
Coffee Dosage Chart photo taken at Batdorf and Bronson in Olympia, WA

Slow Pressing For a Cleaner Cup of Coffee

There will be coffee sediment in a mug of French press coffee. When the first version of this article was written, my only advice was to make sure the filter has a snug fit and then avoid drinking the last mouthful from each mug. Then I learned this trick from barista Christos Andrews (@christosandrews). Thirty seconds before the steep ends, begin slowly pressing down the french press plunger. It should move so slow that it takes a full 30 seconds till it hits the bottom. This gentle press method results in a cleaner cup of coffee.

Last Words

You may find you like certain types of coffee in a press pot more than others. Experiment. Personally I don’t like anything dark roasted in a press pot. I think brighter coffees from East Africa or Central America excel in the press pot. Good luck with your press pot brewing.

Resources

French Press Tutorial – INeedCoffee brewing tutorial.

Keeping Your French Press Clean – Ways to get your French Press super clean.

Superheating and microwave ovens - Page removed from www.physics.unsw.edu.au as of September 2014.

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Michael Allen Smith

Michael Allen Smith fell in love with coffee while attending college. Shortly after graduating college, he found himself in the Tampa Bay area far away from the good coffee he had at The Ohio State University. That is when he starting home roasting coffee. Less than a year later in April 1999, he launched the coffee website INeedCoffee.com. INeedCoffee.com has been going strong ever since with hundreds of articles and tutorials submitted by over one hundred contributors.

In 2007, Michael moved to America's coffee capitol Seattle, Washington. He has visited close to two hundred different coffee places in Seattle, Portland and Vancouver and met many of the top roasters and baristas in the country. Since 2009, Michael has been the Organizer of the Coffee Club of Seattle, which is a Meetup group of over 600 coffee enthusiants. Besides the social aspect of the group, the Coffee Club of Seattle partners with local coffee professionals for educational events such as coffee cuppings, brewing demonstrations and roasting tours.

Unrelated to coffee, Michael has a personal blog at CriticalMAS.com which covers several topics including fitness, cooking and finance.

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