The moka pot (AKA the stovetop espresso, the bialetti, and the moka express) is one of those brew methods that I find feels wildly nostalgic or completely alien, depending on the history you have with it. For many people, the look — and even sounds — of the moka pot can call to mind a strong memory of a grandparent’s kitchen. For others without those sense memories, it’s a big piece of hot metal(?) that people call an espresso machine(?), but brews upside-down(?).
I admittedly fell into the latter camp until very recently. While some time experimenting with a moka pot hasn’t created any memories on par with grandma’s kitchen, learning how to brew coffee with a new method has, as always, been an interesting adventure.
What Is a Moka Pot?
The moka pot was invented by Alfonso Bialetti in 1933, and while some specialty coffee folks bristle at the use of the holy word “espresso” to describe the way the moka pot brews coffee, it isn’t that dissimilar to the original turn of the 20th Century espresso machines, which used steam to push water up through coffee. Water boils in the bottom chamber, eventually building up enough steam pressure to push itself through a pipe and the middle chamber, which is filled with coffee. It then continues up through another pipe and is released into a top chamber.
Moka pot coffee is almost always stronger than drip coffee. That’s because you basically need to get the coffee basket pretty full for the water to flow through well, and there’s no way to get enough water in there to get to a drip ratio. That said, if you used a tiny enough amount of water to get to the same ratio and strength as modern espresso machines, it’d be very tough to extract well. That’s because the amount of pressure built up by this steam process isn’t anywhere near what you get with a modern, pump-driven espresso machine — which is also why you’re not going to get the same kind of thick crema you’re used to at your local coffee shop.
Long story short, I don’t see any good reason to scold anyone away from calling a moka pot “stovetop espresso,” but you also shouldn’t expect to get the same kinds of drinks from it you’d get from an espresso machine.
What's the Right Grind Size for a Moka Pot?
So, enough talk about what a moka pot does and doesn’t do: how can we get it to make the most delicious coffee possible? First, let’s talk about grind size. Grind size is one of the most important determining factors with respect to how much coffee is extracted during the brew process, and therefore in whether your coffee tastes bitter, sour, or just right. Grind size is also where we’re going to deviate most from tradition. Folks often use coffee ground fine enough for regular espresso when brewing a moka pot, and in my brewing and tasting over the past month I just haven’t found that necessary at all.
A medium grind, similar to what you’d use for drip coffee or a pour over, has produced for me coffee that’s plenty sweet but not bitter, while still letting some of coffee's acidity shine through. With the pressure increase and the basically as-high-as-possible brewing temperature, medium is fine enough (though as always, if you brew this way and the coffee is too acidic for you, go ahead and grind finer until you get a result you enjoy).
I will say that I’ve been using a six-cup moka pot. If you’re using a smaller one (or just using less water), the water will take less time to go through the coffee, so you might want to grind a few clicks finer to get the same amount of extraction (though I still wouldn’t want to get anywhere close to a traditional espresso grind). And there’s no reason to tamp down your grinds, the way you would while preparing a shot in a regular espresso machine.
Getting to the Right Temperature
Two other factors that I’ve seen folks in specialty play with while trying to make the moka pot taste delicious are heating the water, and cooling down the moka pot afterwards. With these, I’ve landed on more traditional methods. I tried a few times to heat the water in a separate kettle, then pour it into the moka pot, then put the pot on the stove. With this method, the moka pot spends less time on the stove, which is desirable because the coffee grounds spend less time in contact with super-hot metal.
That said, the flavor differences, especially with a medium to medium-coarse grind, were not positive enough for me to recommend an extra step of handling hot metal. Remember, while your water is heating up, the coffee grounds aren’t in contact with that water, so while heating them up isn’t ideal, it’s not like they’re being extracted from for an extra four minutes.
Another thing I tested out was immediately cooling the moka pot, either by dunking it in a bowl of ice water or wrapping it with a cold, wet rag. The idea here is that you want to immediately cool the moka pot so that it a) stops pushing water through immediately and b) stops the coffee that’s already brewed in the top chamber from being in contact with the metal. These are noble goals, and the latter especially aims to cut down on one of the biggest moka pot drawbacks.
Folks sometimes perceive the taste of moka pot coffee as “metallic,” and while I don’t think any of that flavor is actually coming off of the metal of the pot and into the coffee, there is a slightly off flavor there. My bet is on that flavor actually being the same chemical reaction that happens to coffee as it sits at high temperatures after brewing — the breakdown of chlorogenic acid (one of the flavors that makes coffee taste like coffee) into quinic and caffeic acid, which can taste sour and bitter. That breakdown being accelerated here makes sense, as a result of the coffee coming into contact with the very hot metal of the top chamber for that minute or so while it’s brewing. If we could cool that chamber down during the brew that’d be ideal, but since it’s connected to the bottom chamber we’d cool the whole brewer and interrupt the steam-powered brew.
This is all a long-winded way to say that, while the goal of immediately cooling the moka pot is one I very much agree with, I don’t think the added step improves significantly on just immediately getting the coffee the heck out of the moka pot when it finishes brewing.
How to Clean Your Moka Pot
When you’ve poured the coffee out of your moka pot, the only thing left to do is clean it. This is the part I still find sort of annoying (and why I probably won’t end up reaching for it too often after this article is done). First of all, there’s the aforementioned hot metal, so please don’t try to clean it until you’re absolutely sure it has cooled through some combination of cold water and time. Then, you have to take it apart, and manually scrape the grinds out of the filter basket. You’ll also want to occasionally remove the top filter and gasket, to deep-clean in there.
Finally, every month or two use a mixture like equal parts water and distilled vinegar to stop scale buildup (especially important to make sure the steam release valve doesn’t get clogged). This seems like a lot of work to me. But, then again, for folks who grew up on a moka pot it probably all seems like second nature (compared to, say, carefully standing over a pour over every day, which I do without hesitation). Different strokes!
And Finally... Our Moka Pot Recipe
Our moka pot recipe is pretty simple, and honestly, aside from grind size, probably not that different from grandma’s. But that difference helps minimize bitterness and lets some brighter coffees shine. This recipe was written for a six-cup Bialetti Moka Pot, so if you have a different size or brand, just focus on filling the water and coffee to the corresponding marks and adjust from there (grind a little finer for less water and a smidge coarser for more water).
- Grind 25 grams of coffee at a medium grind
- Fill the bottom chamber of your moka pot just below the steam release valve (in my case around 300 grams)
- Fill the basket to the top with coffee, and use your finger to even out the bed of grinds, but do not press down
- Place the filter into the bottom chamber, and screw on the top chamber tightly
- Place the moka pot on a burner over high heat
- Crack open the lid and keep an eye out while the water in the bottom chamber heats up (this should take a few minutes)
- When coffee starts flowing into the top chamber, start playing closer attention
- When coffee stream starts sputtering more and runs closer to clear, close the lid and immediately pour of coffee into cups or a larger vessel
- Place moka pot either under running water, or back on the stove, making sure it’s somewhere where nobody will touch it until it has cooled
- Dilute, if desired. For this recipe, an extra 100 grams of water should bring it closer to regular drip coffee strength