Guys, I am to the point of tearing my hair out. For the last 2 weeks +, I've been dialing nonstop, researching nonstop, spending countless hours reading and experimenting and still to no avail. I've gone through 5lbs. of beans dialing and have made no progress. I'm still within the return window of the purchase of my Rocket, but I'm not going to keep a machine that hasn't proven to make 1 drinkable shot. I want to give the Rocket a chance, but I will most likely return and buy a Robot if I cannot make anything within the ballpark of a drinkable shot.

Equipment:
1. New Rocket Appartamento, default pressure set at 1 bar
2. Almost brand-new Eureka Specialita with less than 10lbs. of beans through it
3. Have tried 6 different beans from very reputable roasters including Red Bird, all less than 1.5 weeks from roast date
4. Water from my home filter system, which goes through 3 different filters before output. This resultant water is very pure, but not pure to the point of distilled, which I think is just right.

My general technique:
1. Grind into basket (lately I've been grinding into a cup then pouring into the basket cause the cup is easier for me to weigh on scale)
2. Use a toothpick to give the fresh grind a good stir for distribution and clumping reasons
3. Ensure layer of fresh grinds is somewhat even by tapping pf against my palm
4. Tamp with consistent pressure of 30lbs.
5. Cooling flush
6. Insert and extract

What I've tried:
1. Dosing anywhere from 14-20g in stock double basket, but mainly kept constant at 14g or 18g to change other variables.
2. Several different dialing methods, including Jim's (twice using different beans), Clive Coffee's, etc. same results each time
3. The entire (espresso) range of my grinder, including from the point of choking my machine, all the way to obviously way too coarse (extremely acidic, sour, liquidy extraction from the start)
4. Brew ratios ranging from 1:1 to 1:2
5. Proper cooling flush technique, ie insert my single spout pf, wait for steady stream, and quickly insert loaded double pf and extract (Eric said Rocket's are flush-n-go). I tried extracting at idle temps a few times with no luck. But my pressure is on the lower end, meaning lower idle temps, maybe this will work?


Consistent problems:
1. I don't recall ever having 1 drinkable shot. And I know what a good espresso shot tastes like, trust me. I even questioned my sanity the other day and when I went to buy a fresh bag from my local roaster, I bought a shot just to make sure I wasn't going crazy.
2. Bitter, harsh espresso, despite changing all variables
3. Bitter AND sour espresso for certain roasts, despite changing all variables. Even at downdose of 14g
4. I can't extract any sweetness or flavor notes at all. I'm buying top-tier beans from top-tier roasters, I haven't been able to experience anything other then, for varying beans and variables, more sour or more bitter.
5. Early blonding despite changing all variables. I could grind so fine to a point where the first thick, dark drop starts at 11 seconds and flow rate is obviously way too slow, yet 7 seconds later it's already streaming liquidly and very blond. I can't seem to maintain some consistent extraction.

Suspicions:
1. Channeling, though I have no evidence for it. I do not have a bottomless portafilter, nor will I invest in one so soon when this seems like a fundamental problem. I know pucks are meaningless, but I'm grasping at straws here. When I observe them, they do not have obvious signs of channeling.
2. It's plugged directly into an outlet, but could the machine not be drawing enough power? Just a shot in the dark.
3. Some pressure or brew temp problem with the Rocket
4. At one point I choked the grinder while messing with the grind setting knob (espresso problems persisted beforehand). So I took it apart, used a toothpick to break up the jams, and carefully put it back together and dialed it back to perfect working order as before. But maybe I could have done something wrong here?

My next experiment will be to try dosing the single basket single spout pf and see if the same problems persist, but I highly doubt anything is going to change. Any idea what's going wrong, or what I should try next?

Wow, lots of info - I thought I was having problems with my steaming??? You have amazing gear (I have same grinder) and should be getting great espresso as you appear to be doing everything correctly including the most important factor, using fresh beans,- I think you already know that. One thing did not mention in your detailed post is doing time based shots. Does the espresso start pouring at around 5-6 seconds from the time you turn on the brew switch? Then how much yield are you getting at the 25-30 second point?

How long is your warm up?

Can you post a video of your routine?

Buy 5 lbs of coffee next time. Stop changing multiple variables and focus on one. Set dose by using the nickel test (use site search to find this if you are unfamiliar). Use a 0.1g scale to use this dose after discovery of the "correct" dose per nickel test.

Set grind to achieve a pour time of 25 to 35 seconds. Once grind is set, check dose again with nickel test and stick to this dose as long as your grind is consistent. When you change your grind a fair amount, check dose again. Finer grinds sit lower in the basket than coarse grinds.

With no portafilter, you should have a steamy mess coming out of the shower screen when you begin your flush. Do you?

Once you have dose and grind set, your job is to figure out which flush you need to make decent espresso. Flush till the steam stops. Pull a shot and taste. Bitter? Flush till the steam stops and flush for 5 more seconds. Pull a shot. Bitter? Flush for 10 seconds after steam stops. Do this (increasing flush time) until you get undeniably sour. Then back up. If you get bitter at 10s post steam and sour at 15s post steam, try 12. If bitter at 5 and sour at 10, try 7, etc...

You will eventually get something that I call "inoffensive". From there. The rest of the dial in process starts to work. Finer grind and lower dose starts swinging sweeter. Coarser grind and higher dose starts getting "louder" in the cup. But until you get the temperature right, all bets are off.

Please try this and report back. Use the coffee from the shop. Don't change it until you can replicate what you've been served. By then, you will know and understand your machine well enough to try other beans with confidence that you can find the sweet spot.

Cheers!

- Jake

Small suggestion, will not fix all your problems, but might be a part of it.

You are using what sounds to be very filtered water. This is great for protecting your machine from scale build up, but from what I understand it could dimish potential taste. The minerals in harder water help with the extraction of flavor, to put it simply. Not sure if minerals slow down water flow, but might extend the time to blonding since it will be grabbing on to more solubles.

I use to buy distilled water and fill the tank with half distilled and half tap when I first bought my machine. Now I'm filling with just tap. From what I gathered, I dont need worry about this much with the amount of shots that I will pull in my home environment during my machines life. Also, I would rather enjoy my shots and pay for a new heating element many many years from now.

DJL wrote:Wow, lots of info - I thought I was having problems with my steaming??? You have amazing gear (I have same grinder) and should be getting great espresso as you appear to be doing everything correctly including the most important factor, using fresh beans,- I think you already know that. One thing did not mention in your detailed post is doing time based shots. Does the espresso start pouring at around 5-6 seconds from the time you turn on the brew switch? Then how much yield are you getting at the 25-30 second point?

Heh, the steaming on my machine is great, so there's that. So at least I can make myself matcha lattes as I try to figure this stuff out in the meantime...

I keep track of time on every shot. Almost all my shots start at a reasonable window between 7-10 seconds after pump starts, varying based on grind setting and dose, so I think I'm good on that. When I first started dialing I was more meticulous about time, aiming for that 25-30 second window, but now my intuition is much stronger. Lately, more often than not I stop short before reaching the desired time because after a blonding point or liquidation point, I know the shot will just become more bitter and diluted with nastiness.

Jake_G wrote:How long is your warm up?

Can you post a video of your routine?

Buy 5 lbs of coffee next time. Stop changing multiple variables and focus on one. Set dose by using the nickel test (use site search to find this if you are unfamiliar). Use a 0.1g scale to use this dose after discovery of the "correct" dose per nickel test.

Set grind to achieve a pour time of 25 to 35 seconds. Once grind is set, check dose again with nickel test and stick to this dose as long as your grind is consistent. When you change your grind a fair amount, check dose again. Finer grinds sit lower in the basket than coarse grinds.

With no portafilter, you should have a steamy mess coming out of the shower screen when you begin your flush. Do you?

Once you have dose and grind set, your job is to figure out which flush you need to make decent espresso. Flush till the steam stops. Pull a shot and taste. Bitter? Flush till the steam stops and flush for 5 more seconds. Pull a shot. Bitter? Flush for 10 seconds after steam stops. Do this (increasing flush time) until you get undeniably sour. Then back up. If you get bitter at 10s post steam and sour at 15s post steam, try 12. If bitter at 5 and sour at 10, try 7, etc...

You will eventually get something that I call "inoffensive". From there. The rest of the dial in process starts to work. Finer grind and lower dose starts swinging sweeter. Coarser grind and higher dose starts getting "louder" in the cup. But until you get the temperature right, all bets are off.

Please try this and report back. Use the coffee from the shop. Don't change it until you can replicate what you've been served. By then, you will know and understand your machine well enough to try other beans with confidence that you can find the sweet spot.

Cheers!

- Jake

Warm up time is 30 minutes at the bare minimum. Good advice, I thought it was the beans that were the problem, hence trying multiple varieties, but I'll stick with a reputable medium blend from now on. I bought in 12oz intervals, but 5lbs. should be more budget-friendly!

At 18g dose, the top layer of tamped grounds is level with the top ridge of my stock double basket. At a 14g dose, I am quite certain the nickel test will be passed. There's more than half an inch clearance between top layer of tampered grounds and highest edge of pf. I'll do it anyway next time just to be absolutely certain.

Even though I understand Specialita is capable of single-dosing, when I change grind settings, I do it with the machine on and grind into the trash bin so any ensuing grinds go into the basket are ensured to be of the same grind setting.

I have compared the steam level I see from other machines to the steam I see on mine, and initially ruled that out because they seemed similar. I would not classify it as steamy mess, though there is a reasonable amount of steam. I mainly judge brew temp on consistency of water flow out of a single spout pf. Are you implying my brew temp is too low? Brew temp is one thing that I have not explored in greater detail, maybe you're onto something.

Honestly, I'm skeptical your much-appreciated strategy for me to dial will work, simply because it's analogous to what I've already tried to no avail. I'll see if anyone can offer any "short term" tips before I dive full on and do your strategy step by step, because I am going through expensive beans at a fast rate(ie 90% down my sink).

IntrepidQ3 wrote:Small suggestion, will not fix all your problems, but might be a part of it.

You are using what sounds to be very filtered water. This is great for protecting your machine from scale build up, but from what I understand it could dimish potential taste. The minerals in harder water help with the extraction of flavor, to put it simply. Not sure if minerals slow down water flow, but might extend the time to blonding since it will be grabbing on to more solubles.

I use to buy distilled water and fill the tank with half distilled and half tap when I first bought my machine. Now I'm filling with just tap. From what I gathered, the amount of shots that I will pull in my home environment, I do not need to worry about this to much. Also, I would rather enjoy my shots and pay for a new heating element many many years from now.

Definitely something I could try next time I refill my water tank. Should I try tap from my kitchen faucet or what is dispensed from my fridge as drinking water?

RyanLovesCoffee wrote:Are you implying my brew temp is too low? Brew temp is one thing that I have not explored in greater detail, maybe you're onto something

Quite the opposite.

The flash steam generally subsides at a group temperature that will give you ~206° degree shot temperature and will turn most medium roasted espresso blends into harsh and bitter undrinkable swill. Couple this with channeling or other extraction issues and you get under-extracted sourness coupled with burnt bitterness and a harsh beverage that makes you question everything.

You've got to fix your temperature before you can evaluate the impact of anything else. This is why I recommend the BDB so often. You set a temp, you get that temp. Period. There's nothing inherently wrong with your machine, but you have to learn how the flush affects the temperature. If you struggle with time, get thermometer EricS and be done with it. If you don't have reliable flash steam from the group then you NEED a group thermometer to be successful.

Stick with it. Have hope. Many have been where you are now.

Cheers!

- Jake

What about your beans? Even with some of the most capable equipment possible, some beans are just super hard to find good flavors with. I'm struggling with one right now.

-Peter

Jake_G wrote:Quite the opposite.

The flash steam generally subsides at a group temperature that will give you ~206° degree shot temperature and will turn most medium roasted espresso blends into harsh and bitter undrinkable swill. Couple this with channeling or other extraction issues and you get under-extracted sourness coupled with burnt bitterness and a harsh beverage that makes you question everything.

This is... a very good description of what I experience tasting every experiment. Theoretically, bitter and sour should exist on opposite ends of the spectrum, but it's so frustrating to get both at the same time! I guess I do have some other issue going on.

One of my greatest earlier suspicions was that the brew temp was too high, so I experimented with some oddly long flushes like 8 seconds after a constant stream is achieved out of a single spout, and was unsatisfied with the results so I went back to the drawing board. Maybe worth revisiting. I would like Eric's thermometer, because I do think it will help greatly, but because I might not keep the Rocket, doesn't make sense at the moment.

pcrussell50 wrote:What about your beans? Even with some of the most capable equipment possible, some beans are just super hard to find good flavors with. I'm struggling with one right now.

-Peter

Well, I've tried dialing in 6 different beans from a good range of roasters (Red Bird, Nicoletti, several reputable local roasters that are probably considered third-wave type light roasters, even supermarket Lavazza) and they all consistently had the same problems, so it most likely is not a preference or bean issue. Jake had very good advice to stick with one bean from now on until I can produce something that is "inoffensive".

I go straight from the facet . I am not sure where you live or hard your water is. Is it well or city?

I do have city treated water, it still is mildly hard. If you do have well water, maybe try to dilute it with distilled water to even it out.

There are water recipes out there. I have tried them, but I am not a super taster and can not say for sure they made it better.

RyanLovesCoffee wrote:One of my greatest earlier suspicions was that the brew temp was too high, so I experimented with some oddly long flushes like 8 seconds after a constant stream is achieved out of a single spout, and was unsatisfied with the results so I went back to the drawing board.

You can confirm you're in the ballpark with a foam cup and a thermometer.

barry wrote:foam cup method:

take a small foam cup which will fit up against the group gasket (6oz is about the right size), and push a dial stem thermometer through the side about an inch up from the bottom. angle the thermometer stem downwards across the cup and wedge it into the opposite bottom corner. to measure brew water temp, remove the portafilter from the machine and hold the cup firmly against the group gasket on the underside of the brewhead in such a way that you can see the thermometer dial. run about 2oz of water into the cup and watch the thermometer dial for the maximum temperature reached. it's easy to get burned doing this, so be careful not to let hot water run onto your hand.