Help - Going insane

Grinders are one of the keys to exceptional espresso. Discuss them here.
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#1: Post by belfastchris45 »

Hi everyone. Newly registered, long time lurker :-)

I have an atom speciality 65 grinder, approx 8 months old. The grinder was always ok, never amazing, however recently I am losing my mind with inconsistent grinds.

I have tried different beans, full hopper, half hopper single does, all with the same issue.

I set how fine I want to grind ( for espresso) normally 3.5-4 ish. pull through 8-12g of grinds to get it set.

However if I set the timer based on weight of grounds out E.G 7.6 sec and grind straight into the portafilter, I get massive variation. From my desired 18G, to 17.2, 18.6, 18.8, 17 etc. there is zero consistency, I am always needing to take grinds away or add some. Even if that was just the case I could work with it. However

if I get it to 18g, but a 2.1 ratio shot. 18g in 36g out for aprox 30sec. great. The next one I grind, say it comes out at 18.6 i remove .6 from the grinder, pull the shot again, it likely to come out at 36g at 23sec. The grind is never consistent

sorry for the long winded post. Took it apart, cleaned it, hasn't improved anything. Tried multiple scales etc What am I missing, is it just the grinder ? as for the money I expected much better.

is there anything I can do to improve the consistency of this machine ? or is it a situation of moving on to something else. Really frustrated


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#2: Post by Mat-O-Matic »

Change less shot to shot and be tolerant of small variances.

Time-based dosing will yield a different weight when the grind is changed. Finer grinding takes longer, so if the timer is set to 7 sec. and you grind finer, it is normal to see a smaller dose produced in that time vs a coarser grind setting.

Get the grind set to a good place and leave it. Grind settings are normally adjusted in very small increments, possibly only once every few days as your coffee ages. Bigger changes are for new or different coffees. Since it sounds like you are struggling, it's easier to pick one coffee and stick with it until you are practiced and getting better results.

The change from 30 sec to 23 sec for extraction suggests that either you made way to big of a change in the grind, or that puck prep in general is not well practiced. Assuming same grind setting, channeling is the most likely explanation for the faster shot. Bigger doses can be trickier to prep well. You might try a smaller target dose, like 16g.

Using a loaded hopper (full enough that beans aren't popcorning), set the grinder and set a time that produces a dose close to what you want. For now, I'd suggest adjusting output to maintain your ratio to accommodate for slight dose variations. e.g. 16:32 = 16.3:32.6 = 15.7:31.4 are all 1:2. All of these might stop at 32g and be fine anyway. It's not that tenths of gram in dose and yield aren't detectable--they are--but they aren't the cause of big changes in extraction time, and they aren't usually the reason for undrinkably bad shots.

Moving to single dosing-where you weigh the beans first, put them in an empty grinder, and grind them through until it's done-would be the simplest way to gain dose consistency. What you put in, minus a small amount of grounds retained in the grinder, should be what comes out, plus or minus a few tenths of a gram. A small purge (1-3g, not 8-12) would be appropriate. This is not done to set the grind, but rather to evacuate older ground coffee stuck in the grinder from your last coffee. This is worth doing for your first coffee of the day, and is less important if your last coffee was made a couple hours--or minutes ago. Searching these forums for single dosing with your grinder may be helpful.

Reading between the lines, grind consistency may be less of a problem than consistent puck prep overall. Changing fewer variables, futzing less with adding and removing grinds from the portafilter, etc., may bring you closer to regularly enjoyable coffee.
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#3: Post by Michiel_loves_coffee »

Time based dosing on a hopper grinder is good for people who prioritise low fuss easy workflow over getting the best possible result in cup. It sounds like you are of the other camp, and chase the best possible results.

What would be better suited for your style is a low retention single doser grinder. The idea is that you weigh the beans going in, and get exactly the same weight out so your dose will be consistent.

I used a time based hopper grinder for years and accepted the variation in output because I didn't know better. But I'm using a single doser for a year or two now, and would never want to go back to a hopper grinder. Another plus for single dosers is that you can change beans for every shot without having to mess with the beans in the hopper. It's great, I have about 10 different beans at the moment, and pick different ones every shot.

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BaristaBoy E61
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#4: Post by BaristaBoy E61 »

As an experiment, you can also try single dosing with your hopper grinder weighing the dose both going in and coming out.

You might be pleasantly surprised at the result.
"You didn't buy an Espresso Machine - You bought a Chemistry Set!"

belfastchris45 (original poster)
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#5: Post by belfastchris45 (original poster) »

thank for the comment. will try weighted single does to see what that does for me

just very frustrating, trying to get a nice coffee based off basics recipes.

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#6: Post by jedovaty »

Reading the posts, it's ambiguous whether you've tried pulling successive shots without any changes: does your shot timing still vary drastically? If so, you have four possible issues in order:
1. prep (off/inconsistent/missing/problematic)
2. misaligned burrs
3. bean quality/age
4. wrong phase of the moon

For #1: are you performing any RDT, what about WDT, is it the same every time, thick or thin needles/whisk/keypuller, are you thwacking the side of the pf/basket, tapping the basket down, do you tamp consistently and level, do you nutate, spin the tamper, blow the grounds off, using paper or screens top/below, etc. i.e. what do you do with your routine and is it consistent. Some people develop odd habits that can be problematic, e.g. tapping the side of the pf.

For #2: your grinder has flat burrs, right? if so, research a little about burr alignment. it's a painful, boring, annoying, meticulous, asinine, frustrating process, so let's hope #1 is right.

For #3: you mention you've tried different coffees. Okay great. Are they from the grocery store, from megachain coffee shop, from local chain/coffee shop, from local roasters, from well known roasters, random internet roasters, your own roast, are they old, are they fresh, are they stored open or closed bag, did you sneeze on them, stored on counter, freezer, QA'ed by Grace Kelly, brown, purple, blue, violet sky, etc

For #4: gravitational effects will impact the bean's flux capacitor of the inherent moleculular bonding within the subatomic accelerated snickerdoodle chemical ketones and acids, so unless you get this under control, you'll continue to have full frustration. Totally legit.

Good luck!

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#7: Post by jedovaty »

One more thing! Perhaps your burrs just need more "seasoning" according to a lot of experiences I've read about on this forum over the years. You've had the grinder 8 months. Have you run a few kilos of inexpensive coffee through it? If not, something else to consider that may or may not help.