When I am trying to use lighter roast beans, I can't get good results.
I am using ECM Synchronika with Niche Zero. The espresso seems kind of over extracted (bubbles) even if all brewing parameters(time vs yield) are optimized. Taste is also on the acidic side.

Any comments, tips, recommendations? Should I be able to get decent shots from light roasts or not?

That looks messy in multiple ways. Can you make a video of your espresso extraction?

And light roasts... When you're here it sounds like the summum, but in reality it only appeals to a minority (of all coffee enthusiasts, I'd say 10% or so). Your views may get clouded when you're here, but it can just be that you don't like lighter roasts.

In my case light roast extracts fine and often it still tastes like something's off. Note: I do enjoy the wide range our hobby has to offer and explore, but a creamy, sweet, nutty, chocolate medium roast is what I prefer the most.

Have you been able to extract a good light roast before that you keep as a reference? And what beans/freshness and brew temperature are you using? The Niche is not known for its light roast capabilities.

First question is what is "light"? Which roaster are you getting your beans from. Are they promoted as roasted for espresso? Techniques will vary depending on how light the roast is.

Medium-light and light roasts typically will not give you 1990s-style, syrupy shots from any grinder. They will tend to have little crema. I'm not sure why bubbles are related to "over extraction".

Typically medium-light and lighter needs a finder grind, some soak to keep the puck together, faster flow, and often a longer ratio. With a Niche Zero, I found that medium-light and lighter coffees tended to be more balanced around 1:2.5 to 1:3 than at lower ratios. In my experience, the Niche Zero is capable of pulling good shots with lighter roasts, such as Passenger, Luna, La Cabra, Tim Wendelboe, and the like.

sbenyo wrote:When I am trying to use lighter roast beans, I can't get good results.
I am using ECM Synchronika with Niche Zero. The espresso seems kind of over extracted (bubbles) even if all brewing parameters(time vs yield) are optimized. Taste is also on the acidic side.

Any comments, tips, recommendations? Should I be able to get decent shots from light roasts or not?

image

What is optimized time vs yield for a light roast? I have better luck pulling larger shots (1:3.5 to 1:5) in whatever time frame makes it taste good (sometimes 20 seconds, sometimes 40).

The OP's picture is of a milk drink. I think this may be a separate issue from doing shots with light roasts. I enjoy about a third to a half of the light roasts I get as shots; but I have never liked even one in a milk drink. They seem either tasteless or like teetotaler malted grain drinks.

I think this is a new and good question, so I've created a poll to let people give their views.

I use specialty beans from a local roaster which is considered one the best in my area. This is from high part in Brazil with natural processing. It does not state exactly what is the roast level but I know they are roasted light and the beans also look like light roast.

I used many different types of beans and I always had the same problem with light roast. I yield 1:2 in ~25s, but does not matter as the extraction does look "over" anyway. I can try 1:3 but I don't believe this will make a change.

Maybe temperature has something to do with it. My PID is set to 92c. Just to mention I did have to adjust Niche to much coarser grind than I am used to with other beans.

I definitely can get good results with medium-dark roasts. Creamy, sweet, nutty, chocolate as you describe.
See example below.

I'm curious how light that natural Brazilian really is. If the first pic is the light roast then the fines seem awful dark in the crema compared to what I usually get out of a light roast (hardly much crema or dark color like that.)

I think you should take the milk out of the equation and dial in the straight espresso first. What notes are you getting and is it a balanced shot? Sour? Bitter? Harsh? Then we can go from there.

The milk just shows very clearly the issue I am having. Espresso is on the sour side like I usually see in lighter roasts. Not exactly to my taste but it's also not bad and I don't feel harsh tastes to either the bitter or acidic side.

It's definitely behaving the same way I had with other light roasts. It's clear that something is not right if milk behaves like this. Almost like milk and coffee don't work together. I'll try to get espresso only pictures.

i think your bubbly may be referring how the milk cogulates from acid similar to how adding lime and turns bubbly and gives that awful stale taste?

can you do preinfusion?
if yes, tighten your grind, and add 10s (or more) preinfusion before ramping up pressure.
if you didnt hit > 8 bar after the ramp, u'll likely havnt cooked the acid enough to make it workable with milk.
i havnt tried much but i havnt got 6bar shot to work well.

if you got it right, the acid taste will be 'lower/deeper' instead of upfront. thats usually an indication it'll be able to blend with milk instead of fighting it. the shots may be extremely concentrated to be drank straight, but will be more balanced after milking.

heres probably what you hope the cup to look like.
its a medium light i pulled earlier. im out of light beans atm (since i buy 200g, but always several types).
this was pulled 14g in 27g out, 93celcius, 13s pi. shot ran about 27s (includes pi). im on df64 with ssp mp btw. with 1zk it may be a 1:2.2.



the beans.
flavor is dewey, some of the earthy honeylike sweetness, cocoish, with some bitter aftertaste structure on the tongue (brandy?) and obvious lychee aromas. and all these are through the milk, therefore creamy tasting flavor notes.
i wasnt able to exactly discern honeydew here.. and never tried brandy btw.

Try pulling a 1:2.5 shot in around 35-40s and definitely pull at higher temperatures like 94C and see how that works. The 92C you're using is pretty low esprecially in combination with a 25s extraction and both will only promote more sour tasting espresso.

Natural Brasil and light roast sounds awful unless you have that rare Brasil that is good enough to roast light. Sour is intended in light roasts but shouldn't be overly sour and harsh.