Inconsistent Shot Times?

thetravdog

Hi everyone, I wonder if anyone can help me or if it’s just something that happens, but I’m really struggling to repeat the same output on my machine.

I’m shooting for 32 seconds for example with 5 secs pre infusion looking for 19g in and 40g out but my first shot will run slow and I’ll get 31g out in that time, then I run the exact same through the machine, same grind size and temp and it will probably overshoot and I’ll have 45g in that time. It seems a rather odd thing to happen. I’m not expecting 0.1g consistency but surely that’s too high a variance?

I hear someone on YouTube say something like that could be grinder misalignment possibly? Is there any way to rule out my machine? I’m using dosing tubes so I’m sure the coffee in is the same every time.

Just a bit frustrated to be honest!

MWJB

thetravdog If you’re brewing by weight, kill the shot at the target weight (within +/- 2g might be your tolerance).

At the same grind setting and extraction, time will vary a little. If you nail the same time (but get anything between 31g & 45g in the cup), you will have a wider variation in extraction, at the same grind setting.

Your extraction is primarily driven by how much water you pass through the puck, at a given grind setting.

Using this method will leave you with one main variable (grind), at your chosen brew ratio.

thetravdog

MWJB my question is not on the output per se, it’s more that I’m getting such a massive variance! Is that normal? Surely not?

MWJB

thetravdog Well, it’s hard to see what the average weight & the time variance are, at your target weight.

Pull a few shots at the same coffee, grind, dose weight (measured after grinding), output weight (within tolerance) & record the times & taste perceptions, regarding faults/attributes (a basic score, say out of 5 might be handy with 3 being ‘neither like/dislike’).

delta76

Likely something with your DF. If you have a friend who has a better grinder try borrow it to test…

thetravdog

delta76 doh, I have a sinking feeling you’re right, I wonder if I should just test the water output from my machine just to rule things out

MWJB

thetravdog delta76 doh, I have a sinking feeling you’re right, I wonder if I should just test the water output from my machine just to rule things out

Start by establishing what the issue actually is, by aiming for a target & seeing how that works.

thetravdog

I’m not expecting my setup to be absolutely consistent second for second, gram for gram but I just would think it should be within a couple of grams and a couple of seconds each time

MWJB

thetravdog you can’t have consistency to the second, that is just consistency of time, which is less of a priority compared to taste.

You should be able to pull shots to within +/-2g (at 40g out) pretty easily. Going over is likeky to be less disastrous than falling significantly under.

delta76

if same weight, same espresso machine, different time for same output (1:2) then taste will be different. sometimes subtle sometimes noticeable. DF64 even gen2 is not a super reliable grinder. it’s good machine for the price especially if you consider possibility to change SSP burr, but it’s not consistent between machines and even between grinds on same machine.

thetravdog yes, it should be fairly consistent within the margin of error. your dose will vary by a few 0.1gr and output will be off by 1-2s, but should not be much :)

thetravdog

MWJB I understand what you’re saying but I don’t think you’re following what I’m experiencing. I’m not having any issues dialling in by taste, I am just having very inconsistent shot times which is annoying me because sometimes I just want to let machine run for a set amount of time and at least be close to my target output! Sometimes I CBA to weigh my wife’s latte when she’s putting caramel syrup in it anyway!

MWJB

delta76 if same weight, same espresso machine, different time for same output (1:2) then taste will be different.

How much difference is ‘different’? You need to establish a norm & a tolerance.

We are making small drinks, one by one, not large commercial batches, so some difference is expected even amongst shots that are essentially the same. We’re more interested in what the persistent fault in taste is & when those drinks are pleasant, even if different.

delta76

MWJB as I said it’s depend on many factors, the beans, the grind, etc. sometimes you can tell sometimes you can’t. it’s however unpleasant that you make two, one for you was very good and one for your friend is not so. 9 seconds difference should be noticeable.
you pay more to have a consistent experience - it is what you want it to be 99% of the time. I still think that @thetravdog should borrow a better grinder (Niche Zero or something even better) and do some tests

dfk41

I am less scientific than others……the problem, as I see it is either your grinder or inconsistent roasting of the beans. I suspect the grinder since you have told us it is a DF64. I have to no idea how to recliberate but if you can find out how to do that, then that would be my starting point!

MWJB

delta76 9 seconds difference should be noticeable.

Indeed, that would sound like a big difference, but we still don’t know what the actual difference is (same beans, same weights in & out).

FadedFrontiers

How old are the beans?

I’d want to rule out other potential issues like beans, retention, etc before diving into the world of grinder alignment

thetravdog

FadedFrontiers coffee I’m currently using is from Origin, their Beija Flor and was roasted 2 weeks ago today

thetravdog

Yeah I’ve cleaned the grinder out and recalibrated just to check. One change I have made is I’ve adjusted the OPV on my machine and so my shots are climbing up to 9 bar after pre infusion then lowering to about 6 as the puck loses integrity. I’ve just done back to back shots with only a 1g difference in output which is much more like it!

FadedFrontiers

thetravdog Yeah I’ve cleaned the grinder out and recalibrated just to check. One change I have made is I’ve adjusted the OPV on my machine and so my shots are climbing up to 9 bar after pre infusion then lowering to about 6 as the puck loses integrity. I’ve just done back to back shots with only a 1g difference in output which is much more like it!

Oh yeah lowering opv was a very good idea, you don’t want to be any higher than 9 bars. Glad it’s more consistent now, I don’t think many of us will get better than 1g consistency!

thetravdog

I suppose if I wanted shot for shot reproduction to the gram I should have gotten a decent and a better grinder lol, maybe I’m asking for too much, I just didn’t think I’d need to weigh every shot, I could just dial in then have my machine run for whatever time my dial in took, maybe I’m dreaming?!

delta76

thetravdog if you don’t switch coffees that often, yes you can do that. I think @DavecUK does that as well, he dials in and put away his scale
But if you have a small scale it does not take up a lot of space, and then you don’t have to “upgrade” your grinder to a more consistent one. I’d say keep it. I always have my scales (yes, I have two) ready because I trust them more than the grinder (my grinders have been consistent but they can’t beat a scale with precision of 0.1gr)

Adrianmsmith

thetravdog

Not dreaming, just about the wrong machine🤪 need a decent machine like an evo leva for shot consistency to the g, not a machine Decent 🤓😁