Why Does My Aeropress Coffee Taste Bad? 8 Fixes

Does your Aeropress not produce very good tasting coffee? The Aeropress is known for brewing good tasting coffee easily and quickly. So if your coffee doesn’t taste right, something might have gone wrong and it shouldn’t be too difficult to fix it. 

Here’s what you can look to fix when your Aeropress doesn’t brew the coffee you like. 

Biggest Reasons For Bad Tasting Aeropress Coffee

Here are the biggest reasons for brewing Aeropress coffee that doesn’t taste good. If you’re not yet sure how to use an Aeropress exactly, read this complete beginner guide.

1. Type of Coffee Beans

The first thing to check is the coffee you used. Is it a new type you never tried before? It’s possible you just don’t like the taste. Or maybe it’s a very old bag which has gone stale. 

While it’s generally pretty easy to make a good tasting cup of coffee with the Aeropress, if you start with bad coffee beans or grounds, there isn’t much you can do to make that taste better. 

If you use the same coffee with other brew methods and it tastes fine there, it’s also possible that the Aeropress is brining some taste notes to the foreground you don’t like and weren’t as obvious with different brew methods. 

Use fresh beans and grind them just before use to get the best results. If the taste of your coffee is important to you, grinding fresh does make a big difference. A simple hand grinder doesn’t break the bank and will allow you to always make fresh grounds. 

2. Used Water

If your coffee from the Aeropress suddenly tastes weird, check the water that is used to brew. Does it have a weird smell or taste? Coffee is 99% water so if there is a taste to the water, that will be noticeable immediately. Just give it a little smell and taste to see if there’s something weird.

Suggested: Should you use tap water to brew coffee?

Don’t only check the water from the source but also the kettle or whatever else you heat the water in. If it comes out of the tap or filter perfectly fine but there is something in the kettle, that will obviously have its effect. To check the water from the kettle, boil the water as you would for brewing but then let it cool down to taste it. Your taste buds are more sensitive with cooler temperatures but the boiling might release something in the water you wouldn’t notice otherwise.

The used water is more important for the taste of your coffee than you might think. In case something is off with the water you’re using now, it’s best to change the source. Filtered water is usually a good option. 

There are water treatment tablets especially for coffee brewing. These are effective but actually are intended to be used with filtered water as well to get a consistent taste. While effective, for most people those tablets aren’t really necessary and it does get really pricey if you’d use them every day. Tap water is different everywhere so it can produce very different tasting coffees. For most people filtered or bottled water would be the best option. 

3. Dirty Aeropress

Of course there might be something that tastes bad stuck on a part of your Aeropress as well. If it’s been in the cupboard for a few days/weeks, who knows what might have gotten in there. Give your Aeropress and all the surfaces that touch the water a good look and clean. It’s easy and quick to do so there’s no reason not to. 

Of course this also goes for the cup your coffee goes into. 

4. Grind size

Besides the type of beans you use, the grind size is very important to get the right taste out of your coffee. The grind size is simply how big the pieces of coffee are after grinding. Getting the right size for the right brew method is important to get the right taste. 

If the coffee particles are too big, the coffee could be weak and taste sour. If the particles are too small, the coffee can become bitter and sharp. 

What the right size is depends on the brew method (and actually the specific type of beans). For an Aeropress it’s medium-fine which means most particles should be around the same size as normal table salt or a touch finer. 

Suggested: Can you use filter grounds in an Aeropress?

If your coffee is sour, grind a bit finer next time since it’s likely under-extracted. You can also let the coffee steep a little longer before pushing down the plunger and/or stir a little longer. Those are just bandaids for increasing the extraction though and adjusting the grind size is better. 

Bitter coffee likely means the grind is a little bit too fine and should be adjusted coarser. Steeping shorter and stirring less also helps. 

Suggested: Why is my Aeropress coffee weak?

An adjustable grinder is a must to get this right. Pre-ground coffee is obviously impossible to adjust and it’s unlikely to be the right size for the Aeropress since pre-ground coffee is usually ground for either drip methods or espresso machines. 

5. Bloom Time

Coffee brews best when there is a bloom time. This means pouring a little bit of water on the grounds, just enough to get it all wet and then let it sit for 30 seconds before pouring the rest of the water.

This helps get rid of Co2 in the grounds and lets the water do it’s job better afterwards. No matter how your coffee tastes bad, this is a good thing to do. It will result in more depth of flavor without harshness if done right.

In an Aeropress it’s a good idea to stir the grounds a little with the paddle that’s included in the Aeropress. That makes sure all the grounds get equally hydrated which helps extract everything equally. 

6. Steep time

The time between pouring in the water and pushing down the plunger of the Aeropress is called the steep time and it’s pretty important. Just like tea, coffee has to steep for a while and the longer this time is, the stronger it will be. 

Two minutes of total time is usually a good target to aim for (from the start of the bloom time until pushing down the plunger). However, I’ve had decent results with longer steep times as well, especially if the grind size is a bit coarse. 

Weak and sour coffee calls for a longer steep time and overly bitter coffee for a shorter steep. 

Suggested: How Long To Let An Aeropress Steep?

7. Stirring

There is quite a bit of discussion on stirring the Aeropress. In general, most people agree you should stir a little during the bloom time. Then after the steep time, before pushing the plunger, most people say that stirring another +-10 seconds is a good thing. Swirling the whole Aeropress is another option. 

How and if you should change this in your brewing routine depends on how your coffee tastes bad. If it’s too bitter, stir less (skip the second stir or shorten it). In case the coffee is sour and weak, stir a bit more. 

Suggested: The 7 Best Aeropress Accessories

8. Pushing Too Far

One small thing that could cause your Aeropress brew to turn quite bitter is pushing the plunger too far down. This can lead to over extraction which means harshly bitter coffee. 

When pushing down the plunger of the Aeropress, you want to push hard enough to push the plunger down in about 30 seconds. Don’t rush it, pushing too hard really doesn’t have any benefits. 

When you get near the bottom, you’ll likely hear a little hissing sound. That’s the cue to stop pushing. This means instead of water, air is being pushed through the filter. If you push through this air, the plunger will directly push on the grounds. This expels extra water that’s still stuck in the grounds. However, getting this water out often also takes the really bitter compounds with it, causing your coffee to taste badly. 

When putting the plunger in the Aeropress, it’s best to make sure there is a little air gap between the bottom of the rubber seal and the top of the water level. This makes sure you get an audible warning before the seal hits the grounds.