# What is Normal Shot-to-shot Time Variance?



## jzexport (Feb 6, 2019)

I began home roasting a year ago with a Behmor to have access to fresh and better beans than what I could easily get locally. That has been a lot of fun and successful, although I now have a strong desire to get a roaster that has bean temperature and is more easily controlled. That is not the subject here.

I then thought I should start home espresso brweing and bought a Breville (Sage) Barista Express without any idea of knowing what I didn't know. Thanks to this forum and HB, though, I have learned a lot. I stopped struggling with the single shot filter and only use the double unpressurized filter. I bought a 0.1g scale, weigh each dose and brew to a 1:2 weight ratio, which is very different than Breville's volume oriented recommendations. I learned about puck preparation and have worked to be as consistent as possible, including using a spring loaded tamper. As others have reported, I discovered the inadequacies of the built in grinder. I use a Smart Grinder Pro for drip and find it quite adequate for that, so just assumed its implementation in the BE would be OK. It absolutely drove me crazy. The bottom line is you cannot breathe on it with unleashing unpredictable results. I have ordered a Niche Zero for March delivery. I cannot wait.

While awaiting the NZ, I've been concentrating on trying to get consistent results, meaning shot times. I use the same 17G single dose. I am trying my best to do puck preparation exactly the same. I am always only trying for a 1:2 brew ratio. I never change the grind setting. My belief was that by not changing anything, I should get a fairly tight range of shot times. The results are more varied than expected. Surprising to me, I can find know reports on how tight shot-to-shot variation should be.

Here are results from my last 20 shots: 34, 59, 36, 40, 42, 45, 35, 34, 35, 57, 35, 44, 54, 42, 37, 60, choke, 41, 28, 55. The timing is from pressing start until my Felicita scale says dripping has stopped.

So, is this normal? If not, can I blame it on the grinder or is my puck preparation needing improvement?

Josh


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## Mrboots2u (May 10, 2013)

Thats a big variance . Personally I'd til you swtich the pump off.

It's probably a combo of your roasts , gridner ( are you single dosing ) age and humidty of coffee .channeling ( are you using a naked pf)

People will say tamp pressure but in reality it's has the least impact . As long as level.


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## MWJB (Feb 28, 2012)

Why are you always only trying for a 1:2 ratio?

Consistent shot times don't mean consistent results. Your method of measuring is time is new to me. Your timing should be from when you engage the pump, until you kill it. You'll have to work out what sort of time lag that needs to hit target weight.

Can you not go a little coarser & still get a tasty shot at a longer shot (in weight)?


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## jzexport (Feb 6, 2019)

I am single dosing. I do not use a naked filter, so don't know about channeling. The coffee is home roasted Silk Road Espresso Blend from Sonofresco in Seattle to less than second crack. It's less than 4 weeks old.

Timing may be unusual, but consistent. The Felicita scale, like Acaia, has a mode that times from when the scale tares until it senses that flow has stopped. I press the pump start when the scale tares. When I am nearing the desired weight, I turn off the pump. The scale lags a few seconds while coffee drips in after the press of the off button.

I am sticking to trying to achieve 1:2 brew ratio to develop shot-to-shot consistency. I know there are other ways to judge the end of shot, e.g., blinding.

I strive for an even puck distribution. After putting the grind into the portafilter, I do a short WDT with a toothpick, at which point the grinds are pretty level. Then I further gently level with the Razor tool provided by Breville. Then apply the tamper as level as possible and press.

Thanks for confirming these times are too spread out. I am thinking within +/-5 seconds, e.g., 25 to 35.


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## ajohn (Sep 23, 2017)

T


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## Mrboots2u (May 10, 2013)

Imho I'd just ignoren the razor tool. It's not helpful.

Re timing up to you but why establish a system different from 99 percent of everyone else.

Time from pump on to pump off to establish norm .

Single dosing is not helping with this set up .

If you want conisitency don't single dose this grinder.

Ignore the soggy puck commentary above your making coffee not pucks it's not helpful.

To rule out your roasting buy some known beans and test


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## ajohn (Sep 23, 2017)

The OP's scales may have a mode where the mug is auto tarred when it's place on it and the timer starts. Then start the machine. This is what the OP seems to be doing.

On the other hand some do time from the first drip of coffee. The shot time used that way wont be the same as above. for the same results.

Sage's volume comments can be read directly as grams 30ml=30g etc.

The razor tool for the DB and Oracle if it comes with one is useless. Not so the one with the BE and DTP. On other machines people might advice using a coin test to achieve the same thing. I'd advise you to avoid soggy pucks like the plague until you know what you are doing. Then you will find out how low a dose you can use before it causes problems. Same comment concerning adding more.

Both of Sage's grinders will weigh beans in pretty well. Once they have settled down output will be to within 0.1g of what went in providing the setting hasn't been changed. How much coffee needs to be put through them to get them to settle down varies - a fair bit more if from clean. I mostly used my SGP like that. Providing they are ok and not broke, chocked up or what ever some one who can't use them may well find that a Niche doesn't help at all.

The level of shot time variation I would expect is +/- a few seconds. Output correct to within couple of grams. Odd ones in my case would take longer but output would be still be ok.

I'll leave Mrboots to explain how to use the machine manually as I can't remember because I never did.

John

-


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## jzexport (Feb 6, 2019)

I will stop single dosing until the Niche Zero arrives and see if the makes a difference.

The variance was the same when I used two different espresso blends from a local roaster.

Even if you subtract several seconds from the rsported shot times to correct for scale off to pump off, the conclusion is the same on large variance.

The Razor tool was only used as a convenient straight edge for leveling.


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## Mrboots2u (May 10, 2013)

jzexport said:


> I will stop single dosing until the Niche Zero arrives and see if the makes a difference.
> 
> The variance was the same when I used two different espresso blends from a local roaster.
> 
> ...


Feel free to record it how you want . It's just easier when trouble shooting if you time a shot from pump on to pump off, as it's the accepted norm.

As earlier indicated it could be a number of factors at once , so to some degree it's a process of elimination .

As a general rule single dosing and puck prep are under your control . Consistency of your roast I can't comment on.

I am taking for granted that nothjng else is deviating . It's 17.0g in the of each time. That's appropriate for the bakset your using . Coffee is stored sensibly and is adequately rested . So not used day1


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## PPapa (Oct 24, 2015)

ajohn said:


> The razor tool for the DB and Oracle if it comes with one is useless. Not so the one with the BE and DTP. On other machines people might advice using a coin test to achieve the same thing. I'd advise you to avoid soggy pucks like the plague until you know what you are doing. Then you will find out how low a dose you can use before it causes problems. Same comment concerning adding more.


Big claims here. Care to elaborate?


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## Mrboots2u (May 10, 2013)

Once again , a soggy puck is not an indicator of taste of quality of shot .

My coffee is bitter, it must be the soggy puck is as coherent as, my coffee is sour , I should close the curtains

We make coffee, not pucks.

What's in the cup is of primary concern not what is left in the portafiler.


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## PPapa (Oct 24, 2015)

Mrboots2u said:


> Once again , a soggy puck is not an indicator of taste of quality of shot .
> 
> My coffee is bitter, it must be the soggy puck is as coherent as, my coffee is sour , I should close the curtains
> 
> ...


That's my point - Big claims here with no correlation to what's in the cup. Bad shot might as well have a soggy puck, but it doesn't mean that a soggy puck is an indicator of a bad shot!


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## Sam_d (Feb 8, 2019)

Could some one please explain what's meant by single doesing?


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## Rob1 (Apr 9, 2015)

Single dosing is when you weigh your dose, in this example 17g (plus maybe .2g for coffee that'll get stuck in the burrs), chuck it into the grinder and grind it up. Cue lots of tapping, sweeping the exit chute with a brush, puffing air through the top of the burrs while it's running etc etc to get all the coffee out. That's single dosing, i.e. not filling the hopper, so the coffee being ground doesn't get pushed down into the burrs by the coffee sitting on top of it. It leads to inconsistency of grind quality with the vast majority of grinders, unless I'm mistaken only those designed like the Ek43 aren't affected and maybe the Mythos.

Shot times shouldn't vary as much as the OP experiences at all. I get one or two seconds variation if not exactly the same shot time. I store the beans in a cupboard in a ziplock bag and squeeze all the air out every time I open it to get the beans out. If I let it rest for 10 days after roasting and then use it for two weeks after that I wouldn't expect to see a difference beyond a second or two in that time. Over a course of a month + 1 week of using a 1kg bag I saw the shots run 5 seconds quicker for the last week supply Vs the start of the bag.

I've no idea how to explain the variation. Could be a combination of stale grinds from the grinder and single dosing. Could it be caused by adjusting the grinder and not purging all the old grinds out?


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## Sam_d (Feb 8, 2019)

Ohh right got you thanks


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## jzexport (Feb 6, 2019)

Regarding my single dosing, it may be the only thing the Barista Express' grinder does well. I think there is little stale to fresh contamination. I do not adjust the grinder settings. I have found the results to change very much and were not reproducible.

I am soon to switch to a fresh batch of beans and will see if stopping single dosing helps.


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## caffeinegeek (Aug 29, 2018)

I can only comment on my 'all manual' method where I have control over all the elements. I use a Mazzer Jolly grinder I modified to provide adjustable timed bursts. 4 bursts gives me a single shot load which I frequently check for weight, but I can tell from the finished tamped height if it changes. I aim for and get a single shot time of 20 seconds with 8 bar pump pressure.

The shot times change according to which shop beans I use, how dark they are and how old they are, so I want to start roasting my own. The Mazzer micro grind adjuster only needs a very small change to optimize the grind and pour time. I watch the crema as the shot comes out and occasionally I will extend the shot if I think there's some more left. IMHO the grinder and the grind are the biggest factors in achieving consistent shot times. If I'm lazy and the shot drips out slower taking up to 40 seconds, I might leave the grind settings as they are.


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