A moka pot is a great tool but there’s also a bit of a learning curve to get the best results. You might have noticed coffee leaking from the wrong places. What’s the problem and how can you stop this mess from happening?
The biggest reason for a moka pot leaking is that the upper collector isn’t screwed onto the boiler tightly enough or something is stuck in the thread. Another common problem is that the rubber gasket that sits between the filter basket and filter lid is damaged or sits in the wrong location.
It’s easy to get replacement gaskets for moka pots from common brands. They’re not expensive, check out the Bialetti ones here on Amazon.
How to solve these problems and a few other reasons why your moka pot is leaking and what you can do can be found below.
Leaking between boiler and collector
The most common place where a moka pot can leak is the connection between the boiler and collector. You screw those two parts together which opens up the possibility for problems.
Not tight enough
The most common problem when you start see liquid leaking from this spot is that the collector is just not screwed on the boiler tight enough.
Pressure will always find the path of least resistance to get out. So if the coffee finds less resistance by leaking out from the connection, it will leak out there and not get into the collector because making its way up the pillar and into the collector is more resistive.
The simple solution is to just screw it on tighter. Hold both the boiler and the collector and screw it on until it stops moving. It shouldn’t take hulk strength to stop leaking. The collector should screw on most of the way without much resistance. Once you hit the part where there is resistance, you should be almost there, just twist it a little further with medium strength and it should seal properly. Once it stops turning, don’t over-tighten it because you could damage the thread.
Keep in mind not to twist the collector by the handle because it could snap off.
If this doesn’t solve the problem, one of the things below might be the problem.
In a moka pot there are a few parts that all have to be there for a moka pot to work properly. The rubber gasket is a very important part to make a moka pot work. When you unscrew the collector from the boiler, you can see a few parts that sit in between;
- Funnel/filter basket
- Rubber gasket
- Filter lid
See if there is a rubber ring (there should be) and what shape it’s in. It should be relatively soft and flexible and without any holes, cracks or other types of damage. Inspect it carefully and look for any signs that it’s not in the shape it should be.
If you need a new rubber ring and you’ve got a moka pot from a decent brand, you can probably find a replacement ring or you can look for a service center in your area that will be able to help you.
If you’ve got a nameless/brandless cheap moka pot, finding a replacement can be much more difficult. You could give the replacement part from a bigger brand a shot but there’s no guarantee it will fit and work as intended. Also, if you have a cheap moka pot, the replacement part could probably pay for a large part of a new pot.
There is a possibility that a mistake was made when assembling the moka pot. If you put the rubber ring in the wrong spot, it won’t work as intended.
The rubber ring is supposed to sit between the filter basket and filter lid to force the coffee through the filter without leaking out the sides of the filter.
So the proper from bottom to top is;
- Filter basket
- Rubber ring
- Filter lid
However, when assembling your moka pot, it’s the easiest and best to mount the filter lid and rubber ring in the upper collector before screwing it onto the lower part.
Thread is damaged
Inspect the screw thread on both the boiler and collector for any damage. If the thread is damaged it’s easier for liquid to leak out and it’s likely that you won’t be able to screw the parts together tight enough.
If the thread is damaged and any of the other tips don’t work to stop your moka pot from leaking, just replace it. There is no way to properly fix it in a way that’s worth your time.
To prevent the thread from getting damaged, make sure both sides are clean and there is nothing on them. Also don’t over tighten the parts. Most moka pots are made from aluminum which is relatively soft and easy to damage.
There are other parts that can leak besides the screw connection. While that is the most common there are some other places a moka pot can leak from. These
If water is coming from the pressure valve in your moka pot, it’s likely that it’s dirty and residue is stuck in there that prevents the valve from opening and closing properly. Coffee residue and mineral deposits from hard water settle all over a moka pot and also in the safety valve.
Or maybe you tried to replace water with milk. Find out here why that’s a bad idea.
First, see if you can move the valve by hand with the help of a pen or small tool. See if you can get it to move. If it does, just moving it around might break up some of the residue.
The next step is to clean;
- Fill the boiler with water to the top.
- Add a tablespoon of white vinegar and a tablespoon of lemon juice.
- Let it sit for a few hours. (2-4 hours)
- After a few hours, pour out a little water until the level is below the safety valve
- Assemble the pot without any coffee grounds
- Put it on the heat until the water and vinegar mixture has run through the filter.
If you moka pot is quite old and cleaning doesn’t work, it’s possible the valve is just worn out. There is a small rubber o-ring in the valve. Just like any other rubber parts, the harden and break down over time. Once that happens, the water can just get through the valve because it’s not sealed off properly.
For some of the high-end moka pot brands you could find a replacement valve but you’ll have to see if the price of the replacement part is worth it compared to just getting a new pot.
If you have a solid jet of water shooting from your safety valve, you might just have filled the boiler too much. Just fill the water level in the boiler to just under the safety valve.
If all other options aren’t what is leaking the last option is the boiler itself. It’s very unlikely to happen but maybe if you drop your pot repeatedly some place could crack and start leaking. Inspect it closely and if you can find any cracks, it’s game over. Just get a new moka pot.
If you can’t find any visual cracks, fill it up with water (below the pressure valve) and leave it alone for a day. If you can find any water leaking out, it’s finished.
Favorite Moka Pot Products
You don’t need many things to brew good coffee with a Moka pot. Here are the few things you need to make the best possible coffee.
- Moka Pot: Just buy a high quality Moka pot from the get go. The cheaper ones can be messy when brewing. Bialetti is the original and still one of the best with it’s classic looks. They cost a bit more than the cheap ones but these can last for decades and the parts that wear out are easily available for the Bialetti Moka pots. The 3 cup size is good for a single person (Amazon)
- Beans: Good coffee starts with good beans. You can’t make bad beans taste good. Espresso roast beans are good for a Moka pot and will get you closer to that typical espresso taste. Peet’s coffee does a great 100$ Arabica espresso roast. Give it a try, you can get it here on Amazon
- Grinder: Using whole beans means you need to grind them at home. This improves the taste because the grounds are much fresher. A Hario Slim (Amazon) is a great starting point for the starting home barista. If you want a good hand grinder for a good price, check out the TimeMore C2 (Amazon)
- Scales: To get consistent results, a set of accurate scales is essential. Check out this Apexstone scale (Amazon). I’ve been using it for more than a year and while it doesn’t look the sleekest, it’s cheap and just as accurate as more expensive coffee scales. It just reacts a little slower.