Espresso trouble shooting guide

tompoland

Someone on the Australian Coffee Snobs forum figured out that I live close by and asked me to call into his home and see if I could figure out why his new AU$8.000 espresso machine was producing such awful coffee. I confirmed that he had a naked basket and then agreed to call in.

I watched his tamping method which was uneven. After his tamping and before the pour I explained the the pour would be uneven and why the espresso would be both under and over extracted and therefore a sinker. He was a little offended and said that he’s been making coffee that way for 20 years. I told him “in that case you’ve been making bad coffee for 20 years.” Of course, he poured the coffee and is was pretty awful.

Anyhow, once he’d sorted out his tamping technique the coffee was channelling and was equally awful. I asked to see the bag that the beans came in. Turns out the beans were five months old. He wanted to save $20 on a kilo of beans while he tried his new $8,000 machine. Go figure. This man was a giver to the coffee community and a great guy, he’d just tried to take a shortcut.

He had a premium bag of beans from a reputable roaster sitting in his cupboard so we dialled that in and used a reasonable tamping technique and wonder of wonders, he had a great pour.

I was happy to help out because I know how frustrating it can be when you get a new shiny machine and the espresso is not commensurate to the price tag on the machine.

All of which is to say, beyond checking the roast date and a reasonable tamping technique, I know diddly squat about how to fix a bitter or sour espresso.

So I want to develop a trouble shooting check list that anyone can use to fix a poor pour (sorry, just could not resist that).

My plan is to ask you to add, subtract, delete, refine the following, and once we have a broad consensus, I’ll compile the advice into a check list for your approval and publish here. Or you may already have your own trouble shooting checklist or you may have a link to one, in which case please share.

DavecUK

I’ll offer up a few pointers.

Temperature is quite important, if brew temp is too hot or too cool it can affect the shot (bitter, sour).
The actual coffee used being suitable for espresso…not all are
Cleanliness, everything must be clean, portafilter, shower screen etc..
Decent grinder

tompoland

DavecUK ooh great list thanks. Can you tell me a little more about item two, suitable for espresso. How would someone know? Thanks again.

tompoland

UPDATED MARCH 17 - PLEASE IGNORE THIS POST AND REVIEW THE UPDATED LIST BELOW

Trouble shooting checklist

Check roast date first.
Check pour rate to confirm correct grind size. Benchmark is 1:2 ratio over 25 – 30 seconds.

Then, if …

Too acidic or sour then try:
a. Decrease grind size
b. increase brew temperate
c. ???
Too bitter then try:
a. Increase grind size
b. reduce brew temperature
c. ???
Too thin or gassy then try:
a. leave the beans to degas for longer
b. ???
Channelling or spurting then try:
a. Check your puck prep technique (WDT)
b. Decrease brew temperature
c. Check clearance at top of puck (five cent coin test)
d. Increase grind size
e. Dry, warm/hot basket
f. ???
Uneven pour (dark on one side, light on another) then try:
a. Check your tamping technique
b. ???
Sloppy watery puck then try:
a. Check basket size
b. Five cent test (See above)
c. ???
Coffee tastes less flavoursome
a. Check the roast date (beans are going stale?)
b. Is the pour blonding (stop the pour earlier)

Rob1

tompoland

Check roast date first. Ensure coffee has been stored correctly and rested a week or two from roasting. Ensure it has been roasted within the last month or two for best results.

If you want an intense shot pull lower ratios, less intense pull higher. Most equipment will struggle to achieve a high extraction at a 1:2 ratio especially with light or medium roasted coffee, so your starting ratio depends on your equipment, personal taste, and coffee used. Aim to produce a shot in 25-40 seconds and taste the result. Alter grind or ratio to adjust the flavour:

If …

Too acidic or sour then try:
a. increase grind size
b. increase brew temperate
c. increase ratio

Too bitter then try:
a. decrease grind size
b. reduce brew temperature
c. decrease ratio

Too thin or gassy then try:
a. leave the beans to degas for longer
b. could be improprerly roasted or unsuitable for espresso, so try an immersion to see if the flavour improves.

Channelling or spurting then try:
a. Check your puck prep technique (WDT)
b. Decrease brew temperature
c. Check clearance at top of puck (five cent coin test and check there is not too much room)
d. Increase grind size or use a different grinder
e. Dry, warm/hot basket
f. Tamping technique.
g. You may not be able to see channelling and spurting, and a patchy appearance out of the bottom of the basket may not indicate either is actually happening through the puck, but channelling should be apparent in the taste if mouth feel is inconsistent, both sour and bitter, or unusually thin considering the dose and ratio used…..so if your shot tastes fine, and you only think you are getting channelling because you see a patchy extraction on a bottomless portafilter, you may not need to change anything at all.

Uneven pour (dark on one side, light on another) then try:
a. Check your tamping technique
b. Check the machine is level.

Sloppy watery puck then try:
a. Check basket size
b. Five cent test (See above)
c. Nothing, You aren’t making pucks, you’re making coffee. Do not make any changes if the shot is good unless you think for some reason it can get better.
d. Backflush to ensure release valves are clean.

Coffee tastes less flavoursome
a. Check the roast date (beans are going stale?)
b. Aim to increase extraction (grind finer, increase ratio, higher temperature, lower dose, higher flow rate etc).

DavecUK

tompoland It’s a personal taste thing that when a user just can’t get it right it may be the bean e.g. if it’s too sour and they are using a light roasted Kenyan. that acidity might be accepted (and welcomed) by some, others may not like it).

c A different coffee
c might be worth trying a lighter roasted bean
c might be under roasted coffee, or very light and not properly developed
e reduce brew pressure or f increase preinfusion time (reduce prinfusion pressure)
b make sure group/machine is level (spouted portafilter), c make sure shower screen holes are all clear and clean
c check vent valve on E61 is opening completely, d backflush with puly cafe, e some coffees are like that if they have to be ground very fine, many pressure profiling machines will leave a wetter puck if brew pressure drops towards end of shot.
b clean the machine, showerscreen, portafilter

tompoland

Thanks Rob1 great contribution. Appreciated.

tompoland

Rob1 , so try an immersion to see if the flavour improves.

Rob what is meant by this the above phrase? Thanks.

tompoland

Rob1 You aren’t making pucks, you’re making coffee.

BTW - I love this!

(I agree that sloppy pucks should not be a concern but it comes up quite often in the Decent Diaspora forum in particular. I will make a note in the checklist quoting this: you aren’t making pucks, you’re making coffee". Clever

Ernie1

Great list and super helpful, just one thing I noticed-

If too sour should grind size be decreased rather than increased? I’ve always associated sour/acidic tastes with grinds that are too coarse (leading to underextraction) and bitter tastes with grinds that are too fine (overextracted).

I think isolation of adjustments might be worth mentioning too, as in, only change one thing at a time. Don’t adjust tamp, grind size and dosage all at the same time.

Also perhaps a note on how adjusting dosage and grind size can produce similar results. For example if I’m close to the lower end of my grinder settings and I’m slightly underextracted at 18g, I’ll just dose 18.5g rather than adjust the grinder so it leaves some grinder headroom if the bean changes at all over time. This also may be an easier alternative for grinders that are sensitive to small adjustments and reduces purge waste from adjusting the grind.

tompoland

Ernie1 Good post thanks and helpful suggestions. Love the idea of including a recommendation to change only one variable at a time.

Re the sour question, yes i think you are correct. I’ve now edited the post. Frankly some my initial list above is guesswork. Hopefully someone will confirm one way or another.

SouthMark45

This is a good watch and has certainly helped my espresso making massively

Alpesh

Thanks, very useful video and practical tips

MWJB

Coffee cannot be both over & under-extracted at the same time. It can be channelled, which will be under, but bitter (but not over).

Re. sour shots, too coarse at a feasible ratio will cause sour shots, but if your ratio is to short, they’ll get less sour, then more sour and pithy without ever coming right.

This is because extraction rises as you go finer, but eventually you get so fine that the puck doesn’t permeate fully and extraction drops again. If the apex shots are still sour at a given ratio, go longer on ratio.

Rob1

tompoland “try an immersion to see if the flavour improves” It means if you can’t pull a good shot with it then stick it in a french press or sowden (or some other easy brew method) and see if it tastes good done that way. If it does it’s roasted properly….

MWJB’s comments around ratio and grind are important for newbies to understand. It’s better to gain an understanding of these ideas when you start than it is to chase dogma and waste kilo after kilo of coffee never getting a good shot because you tell yourself you’re doing the “right” thing e.g by dialling in the grinder to produce a 1:2 ratio in 25-30 seconds. The forums are full of people asking for advice because they’ve tried everything, different beans, different grind settings, new tampers, new grinders, and are at a loss, and then you find out they’ve always gone for a 1:2 in 30 seconds.

If you give people the idea that they should be aiming for a specific ratio in a specific time and they lack the understanding to make sense of what the implications are, the worst-case scenario they end up convincing themselves it’s supposed to taste sour and strong because they’re doing everything right, so it’s supposed to be like that and it’s just an acquired taste - and they never learn how to make good coffee - go to a handful of speciality coffee shops and you’ll probably run into a few baristas who think that.

Unless you know the coffee, grinder, machine and water in use you can’t recommend a dose, ratio or grind setting. You can certainly aim for something to start with, but it’s far more useful and important that people know how to adjust the grind and ratio based on what they are achieving.

As a starting target, I’d say the goal is to achieve a good extraction, and the most likely ratio to achieve that in 25-30 seconds is not a 1:2 ratio for the vast majority of people out there, especially those with smaller flats or conical grinders and even more so if they are using light or medium roast coffee. If you must recommend a ratio a 1:3 (or more) is going to be much more forgiving. You can make adustments from there easily when you know how the coffee should taste and can be reasonably sure you aren’t making two common mistakes 1) grinding too fine and 2) mistaking the possible bitterness of a low EY for over-extraction.

You could add another aside that judging an extraction based on how it looks from a bottomless portafilter is likely to leave yo chasing your tail because you think all extractions should look like the espresso porn on youtube. Sure, severe problems will be visible like completely uneven distribution or tamps and machines that aren’t level, but other than that it can do more harm than good trying to “solve” ‘patchy’ extractions.

tompoland

Updated list with apologies to @MWJB for not incorporating your comments at this point. Just not quite sure where to put them in without confusing newbies - I’ll give that more thought.

Please review the following and point out my inevitable errors and/or add more ideas. Once done I’ll produce it in PDF form and repost it here.

DRAFT
ESPRESSO POURING CHECKLIST

Foundation checks (before you proceed further)

• Check roast date first. If the beans are more than 30 days post roast they are unlikely to be producing the best espresso possible, other than light roasts which may last up to 60 days post-roast.

• Check pour rate to confirm benchmark grind size is dialled in on your grinder. Get the ratio of bean in to bean out at approximately 1:2 over 25 – 35 seconds.

Prerequisite Equipment (without these, diagnosis is harder and so is consistency)

• Use a naked/bottomless basket otherwise it’s harder to tell what is happening with your pour.
• Weight the beans that are going in and weight the espresso coming out.
• A quality grinder. Hand grinders can be fine. (how to tell?).
• A scale for measuring beans ground and espresso poured.

Then, if …

Too acidic or sour then try:
a. decrease grind size (grind finer)
b. increase brew temperate
c. increase ratio of grams in : out
d. ???
Too bitter then try:
a. increase grind size (grinder coarser)
b. reduce brew temperature
c. decrease ratio
d. ???
Too thin or gassy then try:
a. leave the beans to degas for longer
b. Could be poorly roasted or
???
Channeling or spurting then try:
a. Check your puck prep technique (WDT)
b. Check your tamping technique (even)
c. Decrease brew temperature
d. Check clearance at top of puck (five cent coin test)
e. Increase grind size
f. Dry, warm/hot basket
g. Don’t tap the sides after WDT/tamping
h. Careful not to bump the portafilter when inserting into the group head
i. Are you using a quality grinder with uniform coffee grounds
i. ???
Uneven pour (dark on one side, light on another) then try:
a. Check your tamping technique
b. Check the your espresso machine is sitting level
c. ???
Sloppy watery puck should not worry you, you are not making pucks, you are making espresso. But if it worries you:
a. Check basket size
b. Five cent test (See above)
c. Backflush to ensure release valves are clean
d. ???
Coffee tastes less flavorsome
a. Check the roast date (beans are going stale?)
b. Is the poor blonding (stop the pour earlier)
c. Increase extraction (grind finer, increase ratio of grams in : out, lower dose, higher flow rate)
“Ikky” flavor (often caused by old coffee grinds in the grinder or residual/rancid espresso in the machine)
a. Clean group head
b. Clean shower screen (remove)
c. Clean grinder
d. Clean puck mesh if using one (they retain coffee and get rancid quickly)
e. Clean basket
f. Clean the water reservoir
g. Check the water quality

Other notes

a. Best practice is to change one thing at a time so that you can eliminate some items if nothing changes. If you change two things at a time and it fixes your problem, you won’t know which variable it was that made the difference.

b. Most of us are chasing consistency. Once you change something and you get a great pour, your problem is not solved until you can replicate that result time after time.

c. Keeping a log of what you are doing can help a lot and minimizes the chances of forgetting key information (e.g. optimal grind size for certain roast levels) or jumping to the wrong conclusion.

d. Adjusting dosage and grind size can produce similar results. For example if I’m close to the lower end of my grinder settings and I’m slightly under extracted at 18g, I’ll just dose 18.5g rather than adjust the grinder so it leaves some grinder headroom if the bean changes at all over time. This also may be an easier alternative for grinders that are sensitive to small adjustments and reduces purge waste from adjusting the grind.

Ernie1

On the puck note, I saw @DavecUK drop a golden nugget of info that was a game changer for me. If you remove the PF after a shot and let it drain for a few seconds while you run water through the screen/steam milk/make a sandwich, it usually dries enough to knock out cleanly.

I agree it’s not always relevant to espresso prep (unless it’s a bone dry rock or total soup) but the above is a great little helper.

Dusk

It would be cool if once finished it could be turned into a flowchart to work through

DavecUK

We need to make the main document available through a link on the header of the site. I’ll have a think about the best way to do that.

Meldrew

Great post. This is going to really helpful.