The Story Behind the Light Roast Berry Espresso - Easy Latte

April 2, 2026

It is just a note on the berry flavor in an easy latte we had in the morning, but with a light roast, that is a bit challenge for a lot of machines.

Talk about latte, what a joke! here you go.

“I had my usual easy‑latte ratio of 1:1.5 espresso to milk, and she had her preferred 1:1 ratio because she likes a stronger coffee taste. After a sip, she said she noticed a fruit‑aroma note — something completely new to her. I tried my half and felt the same thing here. What! It tasted like a different category of espresso or latte altogether. Okay not that extreme, but very clearly different from the medium roast type. Maybe this is what a well‑extracted light roast can bring. It was simply better than the one we made yesterday.”

In the espresso world, light roasts are often considered Tough-to-Make, take it as a challenge.  Most home baristas—and even many high-end commercial shops—struggle to tame them, often producing shots that are thin, sharp, and unpleasantly sour. But this morning, we made two espresso shots, one is a medium roast and the second one is the Kirkland Signature Light Roast. Should we call the light roast shot a "Berry Shot"? I don't know if it is natural or not this shot has zero bitterness, the flavor of the shot is acidic with fruit that was quite clear.

This isn't a recipe; it’s just our experience we shared here that a good espresso from a light roast and has the taste of berry flavor is possible at home. We have other post talking about the espresso made from the light roast, but this one shot has really a very noticeable berry flavor. 

The Hardwood Bean

Light roast beans, like a high-altitude Ethiopian, are physically denser and less porous than medium or dark roasts. Think of them as Hardwood vs. Balsa Wood.

• Watch For This: Most machines "slip" on this density. If your water temperature drops even slightly, or your pressure profile is static, the water only strips the surface acids. This results in the "Sharp and Thin" failure we’ve all experienced. We need to have the light roast mindset to fix the problem.
• S01A-9Bar in the kitchen: To unlock the fruit, you need high-energy thermal mass and a linear pressure profile that respects the bean's density.

The "Triggering Event": A Lesson in Thermal Timing

A few days ago, I had a failed extraction. Despite using the same beans, the shot was acidic and hollow. The culprit? Thermal Starting Point - Preheat. I had prepared the preheat as usual, just going with a casual hot water rinse and did not pay attention to the needs of this light roast, a higher temperature to start with.

The Correction (The Success Protocol):

1. The Grind Size: we have a manual grinder. We tune to a finer grind size, one click more than the medium roast. Just one more click down and we don't like choking either.
2. Peak Thermal Saturation: A double-rinse of boiling water to saturate the stainless steel chassis.
3. 10-Second Pre-infusion: We did wait for some "soaking" time before we push the pressure.
4. The pressure Bar: We apply the force on the downward push, the long stroke length allowed us to have response time to adjust the resistance pressure and slow down the flow rate.
5. Flow control: Using the manual ball valve to maintain Slow Flow. Smaller flow rate is maintained by hand, it is easy here with the machine.
6. The Summary: Grind size is finer, not too fine. Preheated up the temperature to the 95C region, and thermal stability is good for 40, 45 seconds. Pre-infusion step is here. The mid-stage infusion is here. The resistance in our manual control is here, to keep up the pressure. The flow rate is slow enough. All factors in, the good result, the good espresso is here.

The Easy Latte

We have an Easy Latte, espresso to milk is 1:1.5 ratio.  The flavor of coffee is strong, not hidden by the milk.

• The Base: A 40g extraction, approximately, eye-measured. Coffee input is from 19g of light roast coffee.
• The Milk: We add milk at a 1:1.5 ratio (Espresso to Milk).
• The Result: At this ratio, our easy latte has no bitterness, the flavor of berry is noticed.

The Conclusion: Take it to the "Standard" Coffee Shop

Most commercial shops would find the light roast is not a easy task. Mostly, the machines, they are built for throughput and medium roasts. It is pain to re-tune it to higher temperature and change target to a slower flow rate. The boiler can be hot but then when the water heats the group head and the basket, the temperature goes down. However, very expensive machines may have a fuller and better thermal stability.  The pre-infusion could be a missing step. The longer shot would have a better extraction. All the knowledge has to be there. The slower flow rate should be maintained. It is doable but just could be missed easily.

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Key Technical Specs:

• Machine: S01B-9BAR (Stainless Steel Body)
• Input Dose: 19g
• Output Yield: 40g
• Easy Latte Ratio: 1 : 1.5 (Espresso : Milk)
• Pre-infusion: 10 Seconds
• Mid-infusion: 5 seconds
• Total Extraction Time: 45 Seconds
• Flavor Profile: Berry/Fruit Flavor Noticeable, Rich Texture, Zero Bitterness.