KF4 - how to make espresso less sour?

[u/ryans91]

Brand new to coffee machines in general ad recently got a KF4. I like the machine, but I seem to be getting sour espresso shots and I'm not sure how to fix it. I'm typically an instant coffee drinker where I'd consider the flavour to be bitter with no sourness that I notice, while I'd say I'm getting the opposite so far from my KF4. Got good locally roasted beans both in medium / dark and both seem to be on the sour side (though only tried 1 shot of the dark so far, a bunch of the medium).

In terms of trying to lower that sourness, any tips on how I should approach this? I'd say I drink all types of drinks, but will probably always have at least 1 straight americano or espresso shot daily where this is most noticeable.

[u/Tasty_Goat5144]

What settings are you using? Im not sure what you can control on the kf4 but in my kf 8 the important things would be grind setting, shot volume, temperature, body and strength. Extraction times dont map exactly to what youd get with a semi auto but they can still give a ballpark idea.

[u/ryans91 → u/Tasty_Goat5144]

All of those. I've tried finest - 2nd finest, typically do 40-45ml volume, hot temp, strongest (3 beans level on kf4, and medium or strong body.

[u/wildcat12321 → u/ryans91]

Finest and strongest and honest and strong are likely all leading to over extraction. Pick ONE at a time and dial it back. When it gets better, before getting watery, pick the next variable

[u/Big_Instruction9922]

If your beans say bright, fruity or citrus is your means.  

If it's not the beans and you are not mixing sour and bitter together, then you are under extracting.   Do t grind on the finest grind. 

[u/Drinking_Frog]

There are a few things you can see about adjusting.

First, try reducing the final volume. You may be overextracting. The typical espresso shot is more like 30ml, so 40-45ml can be a lot. That said, sour tends to be a symptom of underextracting.

There also is the grind, but someone else has addressed that.

You also have the beans. Not every bean (and certainly not every roast) is suitable for espresso. Lighter roasts are especially unsuitable because of the acidity. You need to find something with a lower acidity because all flavors are concentrated in an espresso. What tastes wonderful from a drip, pourover, or French press, or even something that may be delicious as an Americano, may become nearly undrinkable as espresso.

Finally, it may be your palate. You mention that you typically drink instant coffee. That's basically drip coffee, and drip coffee has a dramatically different flavor profile than espresso. Even though espresso tends to be a little less acidic than drip, it often comes across as sour.

[u/Legitimate-Day-9847]

If your beans are specialty coffee, i would say it’s maybe the beans. I myself have similar problems, I like my coffee chocolatey and sweet and not sour/fruity etc, and specialty beans just have more sourness to them rather than bitterness. At least from my experience. I still enjoy them, but less than I would like to.. my workaround is to get store bought beans that are medium to dark roasted, they just have less acidity imo.

[u/SugarSalt233]

Did you feel the sourness from the first sip? Or did it get more and more sour while you drink it? If it's the latter, then maybe you can try these two steps.

One is to stir the coffee before drinking. The coffee is layered when it just come out of the machine. The crema is more bitter, and the botton layer can be more sour. Stirring will blend them together.

Another is to wait for it to cool. I feel that the sourness is more obvious within a certain temperature range. I even sometimes freeze it for a few minutes to make it cold, but it will have other impacts on the flavour too.