Espresso Question
 

Espresso folks,

my shots have been sour lately. I’ve tried using better and darker roasted beans and grinding finer, which helps but not enough. I’m doing 21 g coffee into 36 g shot which takes about 35-40 sec. My machine is a heat exchanger type so I can’t change the brew temperature, at least not easily. The only things I can think of are to change my dose or replace my burrs. The grinder is a Mazza Major with about 7,100 shots on the burrs.

Ideas?

Reddit r/espresso will have your answer.

I assume you are using a triple shot basket? This was working well prior? If so check to see if your burs are tight and that everything else in your grinder is fastened properly, dull burs does sound like a possibility but I would not expect that to change quickly. I'm thinking that if the burs are moving around you are loosing consistency in grind size. Did you check if the burr is running concentric?

I would ask James Hoffmann, he seems very nice and might give you a quick answer or possibilities.

I would try to buy some beans from a local roaster who can also pull a shot there in the store. Then try it at home to see if there is a difference. Lots of variables as you all know. For me at 61 I have noticed my taste buds have changed and I no longer enjoy a strong coffee like I used to. I have also moved to more blonde style beans vs dark roast. Our daily routine is a double shot of espresso and add hot water and a splash of half & half. One cup in the morning only.

You may be over extracting it. Bringing out the acids.

Try doing a more loose tamp and a quicker shot and see how that goes.

Agreed about Reddit. Wow. They go DEEP on espresso.

Also, I have a co-worker who pulls the best shots I have ever had. Want me to find out where his beans come from? They are spectacular.

Doubt its the burrs. You can always clean them as a start.
35-40 seconds should be ok, but is on the long side. Long shots do tend to be richer but can quickly veer towards sour.
You're using a triple basket in a bottomless?
I would check your brew temp with a thermometer in the group or cup. Pressurestats can drift over time and require adjustment.
Sour is usually overextracted, so I'd aim towards a lighter grind and tamp and shorter extraction.
Also, I'm assuming that the brewpath and portafilter have been really cleaned at some point with a Caffiza backflush and a soak of the portafilter other than a simple rinse backflush.

I find Long extraction time usually makes taste more bitter, not sour.

Sour pull is underextracted, usually due to water temp being too low. As an espresso, tunneling (too much pressure) or too short an extraction can be a cause. Source, the many James Hoffman videos.

That is also my understanding. Hence I’m doing dark roast, finer grind, longer shot.

I don’t know how to detect tunneling other than looking for a sharp increase in the flow during the shot, the extreme cases of which would be gushing - I don’t have that, I mean not that I’ve never, but not usually.

Should have said I’m using triple basket in bottomless portafilter. Also forgot to mention, I’m also stirring the ground coffee (WDT) and grooming, before tamping.

I will measure temps and try these other ideas, will try a whole range of grind sizes and extraction times.

I do really need to solve this. I used to like my shots, they were better - to my palate, anyway - than almost any shots I get in local cafes (in Portland, 90% of shots are sour to very sour, in my opinion). Now they are mediocre, about the average of cafe shots. Although I did have a very nice shot in a cafe this week, and will have to go back to that place.

Following.

I'm brand new to this but thus far have found lighter roasts to be too sour for me. Haven't yet figured out what temp does for myself. I do a cortado-ish drink but test sip before I add milk to see if I've stumbled on something. The biggest impact, at least that I've found, on milk drinks is the type of milk. More fat gives me a creamier drink.

Current semi-favorite beans are from a hipster guy up the street who roasts in a cast iron dutch oven.

Did you figure out your problem yet? Figure out a way to check your brew water temp.

I was wondering that just now myself.

https://www.aliexpress.us/item/3256806253149211.html

Google grouphead temp sensor or e61 temp sensor and there are a bunch. Most are around 100 bucks and look very much like this cheap one from ali, and all use similar thermometers. There's a 5mm hex on the e61 that unscrews. Its bsp thread irrc. I run a pressure gauge there for my flow control but might ditch it.

Most machines use a Sirai pressurestat Whole latte love has a vid on how to adjust.

Man - there's a lot more to good coffee than pushing the button on my superautomatic apparently. Some day I'll find the time to get into this.

My brew temp is about 200F (holding probe in the stream).

I’m getting best results - like, semi decent - using dark roast and grinding so fine that the shot lasts over 40 seconds. The stream is very thin throughout the shot, doesn’t grow thicker or start gushing, so I think my puck is holding together.

This makes me suspect my brew pressure is low and I will fiddle with that next. I can adjust the pump pressure, but need to take off the case (or I usually burn myself trying to get a stubby screwdriver down there).

Pressure is another one of those critical variables. Over pressure can lead to tunneling and under extraction. I don't remember what the effect of underpressurization is on the pull. There is a Hoffman video where he has a rigged up espresso machine that records temp and pressure variables and the resulting coffee. Dates 2 to 3 years ago.

The CoffeeSensor flow control is probably the best $150 I've spent on my coffee habit. If your grind and tamp are perfect you can just run it at the normal "wide open" setting but you can profile if you want. And if your grind/tamp is a little off, you can usually save the shot with excellent results by increasing or decreasing the flow.

I wonder if that would work on an Elektra grouphead.

I doubt it, the Elektra design isn't the same as e61...

There is a mod I can make to open the solenoid without starting the pump, thus allowing brew water under line pressure into the group head for pre-infusion purposes.

I've resisted making this sort of mod to the machine, because I don't really want to fuss and fiddle with my espresso.

There are a couple of cafes in the area of Marseille where my daughter's apartment is, that for EUR 1.50 will serve a very tasty shot that I like better than the USD 3.50 shots from almost every cafe in Portland. No fussing with the shot, they have everything dialed and the shots are very good every time. That's my aim.

Does this mean for any given time a hotter water temp will be less sour?

That's a good question. If I recall the monologue Hoffman gave in this videos there may be some inversely proportional wiggle room there, but for the most part it is a dance between so many factors such as pressure - which has at least three variables attached: rise, sustain, and falloff; water temp - similar variables, not to mention water quality; grind and grind quality and consistency; portfilter quality, fitment, and even size; tamp pressure of your puck... just such a god-awful array of variables, it's a wonder it works.

The video where they hacked the espresso machine with a bunch of measuring tools was the most informative on these relationships.

Ultimately, you can "pull" a coffee with cold brewing and not have a sour coffee, but at the hot end, 205°F is as much as coffee can take before no shortness of brew helps, or so say rhe supertasters.

Wow great responses. I’m also voting temp is too low. For the beans I like the happy place is around 203.5. I might adjust down as far as 202.5 sometimes, rarely though. And never higher as it starts tasting burned.

I’ll add: could it be the beans? There can be big batch variations. Nasty beans can taste really sour.

Try bringing home known good beans that you’ve seen deliver scrumptious shots.

It sort of sounds to me like something is off with your machine. Maybe time to upgrade to something with a pid?

"Could it be the beans" I was thinking the same, hopefully he did check that. I normally use the same brand production bean and almost every bag is different, I had one that was quite bad, over cooked dark roast. That reminds me to sent them an email.

Probably not the beans, I’ve tried a few different kinds.

Next step is fiddling with pressure. I now have no idea if I need more or less pressure, so I’ll try both ways.

If the machine doesn't have a gauge and you have a standard portafilter, there are a plethora of gauges set up to screw on to the threads where the spout attaches.

If anything I think you need more pressure. Did you try using a double shot so about 16 G coffee grind in 30G out? I was having a hard time with a triple shot, really have not tried again because the double works very well, will try tomorrow.

What is the status of your water service and source? Has it changed? Some waters are better than others for extraction, and water low in key minerals can result in sour or poorly extracted coffees.

So I tried two triple shots today, beside a double the double tasted better. Not as easy to do a triple shot for me requires a second lever pull to get more water in.

Pressure: it could be.

I once had my pressure bypass go bad, it shunts pump overpressure back to the reservoir. I had to keep dialing grind back to get anything out and I was getting these sour mousey little shots.

In my case it was a spring plunger bypass between the pump and the brew head, whole thing was wrecked inside so plunger couldn't make a seal. I replaced it and all was instantly well.

I've no idea how an electra works, is there a pressure bypass? If its a lever can you make shot go faster by pulling harder? Could it be the spring has broken?

jyi, when you tried different grind setting how coarse did you go? Try getting to about 25sec with about 20g coffee in.

Just found this which could be helpful and interesting: Scace 2 - Espresso Machine Thermofilter - Temperature & Pressure Device


The Scace 2 is the next level of Scace temperature measurement tools and is exclusive to EspressoParts.com.

The Scace 2 Thermofilter gives you both temperature and pressure readings directly at the group. This is where we are most interested in receiving data, and now you can do both. The device is very capable of measuring temperature to within a 10th of a degree. The "T" type thermocouple is very fast and accurate when used in conjunction with a Fluke digital thermometer.

While we are fans of the Fluke brand, there are other brands and models of digital thermometers, all you need to make sure of is that the device can read "T" type thermocouples. Pressure is the other fluctuating factor when we discuss stability in an espresso machine. Knowing your brew pressure is just as important as the temperature, and we have found that coffee can taste quite different at variable pressures.

The Scace 2 Thermofilter has an integrated glycerin filled pressure gauge that provides accurate brew pressure. Do you need a Scace device? The question really should be can you afford not to own one? Having the knowledge of temperature and pressure of your espresso machine is very valuable with regards to quality control.

The Scace 2 Thermofilter was previously only available for the La Marzocco equipment specifically, but is now available for the Nuova Simonelli commercial line as well.

Greg Scace has been around since the early days of internet coffee discussion. Great article here summarizing some of his work: https://canadianbaristainstitute.com/en-us/blogs/celebrities-and-insiders/scace-coffee-tool

just tripped over my box of espresso parts and found I have both a grouphead temp gauge and an extra grouphead pressure gauge. If the electra group has the standard m6 port I'd be happy to lend you the temp sensor and give you the gauge...

^^^ this is what makes this forum so great!

here is my grouphead. Will the pressure gauge work with that orifice?

http://forums.pelicanparts.com/uploa...1707883442.jpg

I tried cutting the shot duration down to about 25 seconds for a 21 g of coffee shot. The shot was better. I will experiment more along these lines.

However, the shot didn’t “look” great - went blonde pretty early. With my usual fine grind long shots, I’m used to seeing dark brown flow until about 2/3rd of the way through. Of course, the taste matters more than the look.