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FAQs

If you have a question that isn’t covered here, please contact us.

Brewing with the AeroPress

Why is it important to use a good-quality grinder?

A good grinder will grind coffee into particles of uniform size. Very fine particles block the flow of water and make it difficult to press. The same blocking occurs if your grinder is dull and produces particles of varying size because the fine particles block the spaces between the larger particles.We recommend using a burr grinder instead of a blade grinder.

What grind size should I use?

Use fine drip or espresso grind. Espresso grind takes longer to press and requires skill and patience for multiple scoops but makes a richer brew more quickly due to more particle surface area. You can use preground drip coffee from the grocery store but you may want to use slightly more coffee or let it steep for a little more time to reach the same strength would reach using a finer grind.

How much coffee does the AeroPress scoop hold?

A level scoop holds 11.5 grams of coffee or about 2.5 tablespoons. A heaping (rounded) scoop of coffee holds 14 grams or 3 tablespoons.

Do you make a larger AeroPress coffee maker for use when I want to brew a full pot of coffee?

We don’t currently make a larger AeroPress. But if you do two or three 3-scoop pressings into an 8 or 12 cup carafe and then top off the pot with hot water, you will have enough American style coffee to serve a small gathering in less time than it takes to brew a carafe of drip coffee.

Why do you recommend brewing with 175°F (80°C) water for dark roasts and 185°F (85°C) for medium and light roasts?

All of our tasters agreed that coffee brewed at these temperatures tasted the best. These temperatures deliver smooth, rich brews without the bitterness and acidity that come with using hotter water. One of the advantages of the AeroPress is the user controls all the brewing process variables including the temperature of the water used. We recommend brewing with water of different temperatures to determine one’s personal preference.

Water Level

Look down into the chamber from above. The numbers on the outside are visible through the material particularly if looking down against a light background.

Ground coffee floating around in the chamber can make it difficult to judge the water level. Try pouring in half of the water, stirring to wet all the grounds, and then pouring up to the desired level.

Some water drips through the coffee and filter before I stir and press. Is that OK?

It is normal for a minor amount of liquid (about 5%) to drip through prior to stirring and pressing. If a lot of liquid runs through prematurely, remember to shake to level the grounds and pour the hot water slowly. If an excess amount still runs through prematurely, you need to use a finer grind of coffee.

Am I doing something wrong if it is hard to press?

  1. You may need to use a better or sharper grinder. A good, sharp grinder (ideally a good burr grinder) grinds coffee into particles that are all the same size. A cheap or dull grinder produces a wide variety of particle sizes and the very small dust-like particles at the fine end of the particle size distribution block the flow around the larger particles, turning the layer of coffee particles into a barrier that blocks your pressing.
  2. Press gently, there is no rush. Pressing hard actually compacts the coffee particles into a barrier, making it harder to press. You can try pressing down half an inch, then hold the plunger there and let the air pressure in the chamber do the pressing for you. Then after 5 or so seconds of waiting, press another half inch down and repeat until finished pressing.
  3. If the above two points don’t work, use a coarser grind until you get to where a minor amount drips through prior to pressing and slow, gentle pressing takes 20 to 40 seconds.

Other AeroPress Brewing Methods

I have heard of brewing recipes for the AeroPress that are completely different from the ones provided in the instructions. What is the best way to brew with the AeroPress?

The instructions provided with the AeroPress and also available to download from this website describe a starting point from which users can deviate if they wish. The taste of brewed coffee is affected by all the variables in the brewing process. When using an AeroPress the user selects the water temperature, the brew time, the coffee to water ratio, etc. The AeroPress enables the user to control all the brewing process variables and thereby brew a particular coffee with a desired brewing recipe. Taste is personal. There is no right answer to the question of how to brew a particular coffee and there is certainly no right answer for how to brew all coffees. With that said, we think the method described in the instructions is a good one for most coffees.

What’s the advantage of using the “inverted method” with the AeroPress?

People who use the inverted method do so to prevent any premature drip-through of their coffee and to give them complete control over usually longer brew times. If you want to use a long brew time, we recommend using the normal method but insert the seal on the end of the plunger a half inch or so into the top of the chamber to stop drip-through while waiting for your longer brew time. The seal stops drip-through just like putting your finger on the top of a straw stops dripping out of the bottom of a straw. We think shorter brew times brew better tasting coffee but taste is certainly personal and people should brew their coffee the way it tastes best to them. Be advised that using the inverted method may increase the risk of spilling hot water and the risks associated therewith.

Filter Questions

Is there dioxin in AeroPress paper filters?

No. The bleaching process used by filter paper manufacturers until the late 1980s used chlorine gas and the chlorine gas bleaching process created dioxin as a byproduct. In the late 1980s the filter paper mills switched to using what is called the non-elemental chlorine bleaching process (they use a chlorine compound, not chlorine gas) to eliminate producing dioxin as a byproduct.

Do you recommend using a metal filter in the AeroPress?

Every AeroPress coffee maker comes with 350 AeroPress paper filters. We do not manufacture or sell filters for use in the AeroPress made of other materials such as metal. We were originally planning to include a metal filter with each AeroPress but when we conducted blind taste tests comparing paper filtered coffee with metal filtered coffee, the paper filtered coffee always won. We also learned using a paper filter is healthier because it removes diterpenes from coffee and diterpenes are potent agents that raise your bad cholesterol. Metal filters do not remove diterpenes. AeroPress paper filters are 100% compostable along with the coffee grounds and they retail for less than a penny and a half each so they are gentle on the environment and your wallet. That said, while we think that paper filters brew better tasting coffee, taste is certainly personal so people should brew their coffee the way it tastes best to them.

There are many companies that manufacture filters designed for use in the AeroPress coffee maker made of other materials, particularly metal. We do not object to these other companies selling their filters but none of them can legally use our AeroPress trademark. It is important to note that the AeroPress limited one year warranty does not cover operation with a filter made by another company or damage to the AeroPress caused by use of such a filter.

AeroPress & Health

I’ve heard that coffee contains cholesterol-raising elements. Are those elements present in AeroPress brewed coffee?

Cafestol and kahweol are diterpene molecules found in coffee. They are powerful agents that cause our bodies to increase the low density lipoproteins (LDL or “bad” cholesterol) in our blood. Cafestol and kahweol are removed from coffee by paper filters. Any coffee maker using a paper filter (such as the AeroPress coffee maker) removes virtually all of the cafestol and kahweol from the brew. We had this verified by an independent test lab for AeroPress brewed coffee.

AeroPress brewed coffee seems gentler on my stomach than coffee brewed other ways. Why is that?

AeroPress brewed coffee contains about one-fifth the acidity of drip brewed coffee and one-ninth the acidity of French press brewed coffee. Because of this it’s easier on your stomach.

Does AeroPress brewed coffee have more or less caffeine than coffee brewed in other devices?

Tests done by an independent researcher showed that the caffeine content of AeroPress brewed coffee is the same as comparable strength coffee brewed using other methods. People often find they enjoy their coffee stronger when it is brewed in an AeroPress because of the lack of bitterness, so that would result in more caffeine per cup.

Design Questions

Why did you take the numbers off the plunger?

We stopped putting the water level marking numbers on the plunger because we were concerned that they encouraged the use of the plunger in microwave ovens and we just do not know what effect microwaves have on the life of the rubber seal.

Why are there holes in the sides of the filter cap? Doesn’t the coffee coming out of them miss being paper-filtered?

The bottom circular rim of the chamber is firmly clamped down on the paper filter when you screw the filter cap onto the bottom of the chamber. Therefore all the coffee that you press down must go through the filter paper. There is a tiny amount of coffee that instead of going straight through the filter and into your mug goes sideways through the filter paper and emerges outside of the chamber in the filter cap. The side holes in the filter cap are there to enable this small amount of coffee to drip down into your mug. If those side holes were not there, some of this coffee would be pushed up and over the rim of the filter cap and then drip outside your mug.

What are the maximum and minimum mug diameters the AeroPress fits?

The biggest mug you can press into with the AeroPress has a top inner diameter of 3 3/4 inches (95mm). The smallest mug you can press into with the AeroPress has a top inner diameter of 2 5/8 inches (67mm).

Why did you remove the four ridges on the outside of the plunger?

We removed the ridges because they were scratching the inside of the chamber and had no function. We initially put the ridges on the plunger because we thought they would provide needed additional strength. That was not the case and to our surprise they were a source of scratching of the inside of the chamber.

Cleaning The AeroPress

Can I clean the AeroPress in the dishwasher?

You can in the top shelf, but a simple rinse is sufficient because the plunger wipes the chamber.

Seal Troubleshooting

My seal is sticky. How do I clean it?

The seal can be cleaned using hot water and dish soap. We advise you to occasionally remove the seal from the plunger and wash it inside and out with hot, soapy water to prevent the accumulation of coffee oils. Use a paper towel to provide a little abrasiveness.

My rubber seal no longer forms a tight seal with the chamber. What happened?

Your seal has become compressed and is no longer big enough to tightly seal the chamber. Whenever the seal is inside the chamber, it is being held compressed. Eventually the compression forces prevail and the seal becomes too small. To maximize the life of your seal you need to minimize the time your seal is held compressed. This means eject the spent coffee immediately after every pressing and store the seal either pushed all the way through or removed from the chamber.

What can I do?

Buy a new seal: The seal can easily be replaced on the end of the plunger so one solution is to buy a new seal by calling our Customer Service Department at 1-650-493-3050 (if you live in the USA) and by contacting the importer/distributor in your country (if you live outside the USA). With care, a new seal should last at least three years.

For a quick fix: Joe Lindsay sent us his short-term fix: First place the rubber end of the plunger in some hot water for a couple minutes. Then press the rubber end of the plunger onto a flat surface such as a cutting board. While pressing roll the seal around on its edge so that you are pressing the edge out, widening the circumference of the seal.

The seal came off the plunger. Can I put it back on?

Yes. The black seal is fitted onto the end of the plunger. There is no adhesive. To fit the seal back onto the end of the plunger, position the seal on the end of the plunger and then turn the seal while pressing it onto the plunger until it gets fully seated.

Miscellaneous Questions

How much does the AeroPress weigh?

The weight of the AeroPress (including the AeroPress, the filter cap, the filter holder, the pack of 350 filters, the scoop, the stirrer, and the funnel) is 13 ounces. The weight of the zippered nylon tote bag alone is 0.5 ounces.

When camping, backpacking or traveling light, the parts of the AeroPress you would take along (the chamber, the plunger, the filter cap, and however many paper microfilters you thought you’d need) weigh 6.5 ounces. You would leave the AeroPress filter holder, scoop, funnel, and stirrer at home, and use whatever spoon you were already bringing on your hike as a scoop and stirrer.

How do I separate the chamber and plunger?

Holding the AeroPress with the seal facing you, brace your fingers around the chamber flange and push both of your thumbs against the seal. This will push the plunger up through the chamber making it easier to pull the two pieces apart.

The filter cap is stuck tight onto the chamber. How do I remove it?

This is like removing a screw top lid stuck on a jar. You can try lubricating the filter cap with a little water or cooking oil to make it easier to turn. Or, you can buy a sheet of rubber like material that is intended to help you grip the lids of jars to make it easier to twist the lids – try using one of those. You also can try running hot water over the filter cap (not the chamber). The filter cap expanding with heat may make it easier to turn.

Material Questions

What material do you use for the seal?

It is a medical grade thermoplastic elastomer that we buy from a supplier for medical syringes. The chemical name is styrene-ethylene-butadiene-styrene. It is made in the USA and is FDA and EU approved for use in contact with food.

Does the AeroPress contain BPA or phthalates?

No. The AeroPress has always been free of phthalates and has been free of BPA since August of 2009.