How to reduce acidity (and increase strength) of moka pot coffee?

Question

I drink coffee, from a stovetop moka pot. I do not add anything to it. No milk, no sugar, no water. Just the output of the moka pot is drunk, by me (not sure, if that is the norm).

I have read in some places, including other questions in this SE, that to reduce acidity, one must allow water to be in contact with coffee, for a longer duration.

I have tried to reduce the flame, as soon as the coffee starts pouring into the top part of the moka pot, to increase the time of brewing. However, this only seems to marginally decrease the acidity.

The coffee also doesn't seem strong enough. Is there any way to increase strength, and decrease the acidity?

A better way of doing what I tried is also appreciated.

PS: I am looking for ways to archive result by changing brewing methods, and not means.

Answer 1

Both issues you're describing, high acidity and weak body, are most probably a result of under-extraction. To increase the balance of the brewed coffee and get a more intense body by increased extraction you have several choices:

1. Longer brew time. As you said, this is difficult to achieve with a moka pot.
2. Increased temperature. This is also practically uncontrollable with a moka pot.
3. Grind finer. This is probably the variable which has the most effect on your brew. If you grind finer, you get more surface area and higher extraction (all else being equal of course). Keep in mind this will make your coffee less acidic but also more bitter.

In general, a moka pot doesn't allow for much customization and precise adjustments. The only thing I can strongly recommend is to keep everything you're doing the same from brew to brew and only adjust the grind size.

If you don't own a grinder and use pre-ground coffee I'm afraid you're out of luck. Getting a cheap-ish hand grinder (usable and consistent hand grinders are available for 30-50$/€) and using freshly ground beans instead of pre-ground coffee is an upgrade I strongly recommend.

If you're interested in deeper exploration of coffee you can check out this video with 2007 World Barista Champion James Hoffman about how to make a good cup of coffee with a moka pot. He also has a lot of videos his main channel about coffee.

Answer 2

Mokas are designed for a fixed water / coffee ratio, given by the volumes of the respective chambers. As a baseline, you should always fill up both, for the water until just below the valve or to the given fill line (if your pot has it), the grounds chamber gets filled up to the top, but not tamped or compacted (or only ever so slightly).

That leaves mostly grind size and to a far lesser degree brewing time as parameters. Aim for a comparatively fine grind - finer than for pour-over, a bit coarser than for espresso. Try to go down with the grind size until you start to see some dust at the bottom of the upper chamber, but not so fine that it clogs up. As you have a largely fixed and rather short extraction time, coarse ground coffee won’t be extracted well, giving you an under extracted brew.

Some coffees, especially lighter roasts that have a more acidic and floral notes, are not ideal for a Moka. But assuming that you are using the same coffee as in your other post, a full chamber should be a good first step, the half-full chamber means you don’t get the desired pressure in the setup and an underextracted (-> weak and acidic) brew.

Answer 3

Grind fine as you can. Use little less water. Brew for longer. Don’t boil water, maybe try & bring temperature down using a food/meat/milk thermometer probe.Experiment with all these in small increments & failing that try a darker roasted coffee. Kenya & Tanzania coffees tend to be most acidic especially when lightly roasted.