So the grinder on my breville oracle touch is very inconsistent. Along with the hopper that heats the beans over a few days the grind will change pretty significantly. Generally I used to try to get 1:2 shots out in about 30-40 seconds (counting the 5-10 sec preinfusion it does).

Sometimes I get shots that "stall" - very SLOWLY dripping out. I used to toss these and re-grind. But a few weeks ago I decided screw it I'm just going to keep going. So I ran the shot for like 90 seconds or more to eventually get to my 1:2 ratio.

It was the best I've had from this machine! Much more TDS and thicker and tasted better.

Is there a name for what I'm doing? Anyone could teach my why this doesn't taste bitter and nasty?

Honestly keep shooting for that regardless of what some consider it to be. I always dial in for very long/restricted extractions as after having tens of thousands of doubles it's exactly what I like. The only concern I'd have in a 90 second extraction would be pushing the longevity of the pump as most stock pumps tend to be a 50% duty cycle, as in 1 min on/off.

Just so I undertand your ratio ... your starting with say 18 grams of ground coffee and ending up with 36 grams of liquid? Yikes, if I go over 30 seconds, I get the super bitter "ash tray" taste! It's taking you 90 seconds on a 1:2 ratio? What is that grinder set on, "ATOM?"

If it's changing that much, it's probably the grinder. I know it's an expensive machine but I'm willing to bet the grinder in there isn't going to be as good and consistent as a top notch stand alone grinder.

Welcome to H-B!

You're pulling a low-flow shot. It's probably not nasty for some of a variety of reasons:

* At a 1:2 ratio and relatively low flow, you may not be getting close fully extracting the coffee
* Your coffee, though potentially dark roast, may not be so poorly roasted as to reveal tarry, charred, burnt, or other unpleasant notes
* Your point of comparison may be espresso that others would consider overly bitter
* You may be hiding it under milk and/or sugar

That things aren't consistent for you suggests that there are inconsistencies in the grinder and/or the coffee. With the coffee, it is typically a one-direction progression. Some classic espresso beans have been said to go bad in a day or two after opening the factory pack.

Are you weighing your dose?
You could be getting a large variation.

Do you purge the grinder for a couple of seconds to clear stales?
If not, sequential shots could be vastly different.

Whatever it's called I see this sometimes too. I don't know why I occasionally get a much slower flowing shot. I do weigh my coffee carefully. My grinder has virtually no retention.

Jonathan Gagné has noticed the same thing -- low flow, high puck resistance outliers -- in a carefully controlled study of the effects of varying types of puck preparation. His thought was that maybe puck preparation is hard to do really well and that the outliers might just be those rare times he got it perfect. I wonder if pucks are inherently unstable, prone to channeling, thus making a perfect shot a rarity. The recent paper by Hendon and others addresses this issue.

But I'm not really sure what's going on.

Less than 1 a week [25 shots] is an outlier here, usually faster, almost never slower.

I put it down to higher proportion of sub-par beans. If I take the trouble to remove quakers, shells, malformed, etc. never happens.

cafeIKE wrote:Less than 1 a week [25 shots] is an outlier here, usually faster, almost never slower.

So either that means you get it perfect nearly all the time or you almost never do. :-)

My grinder puts in about 21g and I pull usually around 42-44g out

I've started grinding super fine to purposely create this condition now. The liquid coming out looks so thick and creamy like many of the shots I see coming from high end equipment. Before it was watery pretty fast when the grind made for a 30 second shot

I appreciate the comment about duty cycle. Will try to keep the shots right at about 60 seconds then

But how did that 60 second shot taste? Was it good? Did it burn through the countertop like when they cut the alien?