Hi All, im using st ali orthodox blend and input of 18 G out 30 grams in 30 seconds. It is quite decent drank as an espresso however when made into cappuccino and latte has a lingering bitterness at the finish. How should i approach to remedy this ? Thanks in advance for the replies!

Is it bitterness like an "off" flavor, or is it bitterness like cocoa or baker's chocolate?? There's a real difference. One is bad coffee, the other is a specific flavor.

Your brewed weight seems a little high, but that's without knowing expected parameters. What is the roast level of the espresso? What kinds of flavors are you getting as an espresso, and what temp is your milk? I noticed that they characterize it as milk chocolate, but depending on actual roast level, it could be more bittersweet or dark.

It seems more like and off flavour - even though i added more milk the bitterness seems to punch through it. As an espresso , i could taste a lot of dried fruit and hint of citrus, the sweetness only comes at the end. Did not get the milk chocolate flavour though.The roast level was medium. What brew ratio would you normally use for such roast level? My milk is about 143 Fahrenheit. Should i tone down the brew weight?should i coarsen the grind?

Is it the bitterness at the finish after each sip or at the bottom of the cup?

It is after each sip

Jacksen wrote:It is after each sip

That blows theory number one...
Have you tried the espresso as an Americano? Or maybe even try it after it approaches room temperature. Maybe a different milk? It seems contradictory in that I would expect a slightly bitter espresso to be decent (or at least less bitter) in milk.

Overheated milk will do that. Could this be the case here? How are you measuring the milk temp? Many of these milk temp gauges are quite laggy. For example, they will still be reading 65C when the milk has hit 70+.

A really easy way to tell if it's the milk would be to taste the milk alone after heating. If it's overheated milk, you'll isolate the problem immediately.