cafeIKE wrote:... Tolerances and the unwillingness of others to consider them have been the bane of my professional life. I've acquired an avoidance of claiming accuracy better than worst case.

Believe me when I say that I live with the same never ending battle of convincing the powers that be that tolerances MUST be considered! But I also have come to accept that you cannot always assume the worst stack up. This would only lead to over controling, managing, designing and cost.

So I will use my $20.00 "crapola" scale and accept that the accuracy may be less than perfect.

I thought it worth shelling out on an Escali scales that claims 0.1g accuracy. When I use it regularly, the consistency it gives in pour and taste is I think more than adequate and certainly nothing I feel I need worry about. Whether a cheaper scale would have proved as accurate or as long-lasting I have no idea, but I suspect so....

I do, however, wish it didn't switch itself off so quickly..... Sometimes I'll do a top-up from the SJ doser, or a little scrape with the doser lid to get things where I want and the thing's switched itself off! Fortunately the weight of single and double baskets is now etched in my mind, so torturing myself with a little mental arithmetic gets me what I need to know....

Cheers

Mike

FWIW, have the exact same behavior out of mine... As well the tare button is so small that it is difficult to use. So I subject myself to the mental calculation (It should be easy enough but, somehow, early in the morning before the caffeine has kicked in, it just isn't)

I was yesterday considering some extra expense to dig out a model that is easy to tare and will not turn off so quickly.

For those, who care, yesterday morning little experiment session went as follow:

Argento, imported italian blend, inert gas packaged. Last shots from a 1 kilo bag (openned 2 weeks ago).
La Spaziale Vivaldi II.
92° Celsius (197.6 F).
8.8 bars (128 psi).
6 second pre-infusion, 1.7 bar (25 psi) regulated line pressure.
Rancilio MD40 doser grinder. set at 4.5 notch from contact.
All shots pulled and left to settle for approx. 5 minutes. Remaining crema stirred in before first taste.
All shots weighed on $20.00 "crapola" digital scale.
Shots are served in Bodum, pavina double walled shot 2 ounces espresso glass.

1-Double 15g, made a significant attempt at maximizing even distribution with fluffing but with a somewhat large instrument. I don't have a dissecting needle so I use a Stainless nail. Leveled carefully, light tamp while nutating, 2 quick pull out, to "suck" the ground's in, and final tamp with espro click (30 lbs). Polish with tamper weight only.
---> Very good looking pour. Nutty with honey, full bodied, very little acidity, the normal taste for a very good shot of that coffee. Nearly 1 inch of very nice speckled, gooey, crema, persisting and reducing to 1/8" after settling.

2- Single 7.5g. Distribution fluffing. No leveling. Just tapped the basket on the counter and nutating tamp lightly; much lower than 30 lbs (guestimate at 10 lbs).
---> Fast poor, quick blonding. Taste weak, thin bodied, on the bitter side, no honey. Drank half and sinked half. Crema was 1/8", less gooey, lighter color, settles to 1/16" gooey top.

3- Single 7.5g. Grinder set 1 notch lower, No distribution, no leveling just tapping and light nutating tamp.
---> Slower but still fast pour, blonding is much later. Taste thin, no bitterness. Crema is nice and 1/2" settles to 1/16".

4- Double 15g. Grinder set back, no distribution, no leveling no counter tapping and light nutating tamp directly on the top of the mount of coffee (my lazy no fuss way).
---> Very good looking pour. Nutty, more bitter chocolate and less honey than (1), full bodied, very little acidity, the normal taste for a very good shot of that coffee. Nearly 1 inch of very nice speckled, gooey, crema, persisting and reducing to 1/8" after settling.

5- Same as (4), Same results as (4). Did this quickly to get out of the house. You may disregard this one.

This is where I stopped. In conclusion:

I mixed up way to many parameters!
I do not usually make singles, this may account for the poor results of (2) and (3). But It could also be that I just do not like singles.
The difference I saw or tasted between the groomed shot and the 2 non-groomed is more honey, more clarity and a more balanced pleasant acidity. The difference was significant enough that I was disappointed with the non-groomed shot, but the taste was still good both shots were within my normal "newbie" range of variation.

Day two
2.1- Repeat of shot (4); the "lazy way". Same result (as far as memory can tell) as the day before.
2.2- Repeat of shot (1); the "groomed way", but with a safety pin instead of a nail to do the fluffing. WOW! The absolute best shot I ever made!!! Visually the same as the day before. The taste was again much better than (2.1) (the "lazy way"), but even better than the groomed shot (1) from the day before. Nice silky sweet chocolate, honey and fruits. Perfect (from what I have tasted so far) clarity and acidity.

I am going back down to try to repeat...

2.3- The pour was not as nice visually. A few blond blurps and one 4 second spritzer at the end. Stopped the shot 2 second earlier than (2.2). WOW! The crema was not as thick and persistent but only by a fraction. Taste is just as good!

Conclusion. There is no disputing the fact that the shots are WAY better with grooming. Had my way gone too sloppy or is it that my equipment requires it? I don't know, but I will do the WDT for a little while... This has been a very humbling experience...

That's the way to do it!

A couple of suggestions: Try not tapping. Try not doing your "sucking" pull on the tamper. You may find you get even better results.

I'd also recommend trying to get some really fresh coffee in....

Glad to hear it's all working out.

Cheers

Mike

I'm using a Vivaldi II, and a Super Jolly.

And I'm using Counter Culture beans - 4 to 14 days after roasting, usually.

I posted a page or two back that I did better without the 30lb tamp. Which has been difficult to reproduce, I have been too inconsistent with my weights, even though I do weigh each shot - the urge to not waste coffee when overdosing has been strong Wish I had written down the dosages

I tap on the counter several times to distribute after putting in about 2/3's of the dose, and tap again after the rest of the dose is in. Light nutating tamp.

I've been getting pretty good results no matter which way I do it, sometimes really, really good.

I'm thinking MichealBenis is right, fresher coffee will likely help a lot, and I'm thinking the "sucking" pull can't help.

I figure that the least effort and ritual we can do the better the shot - Plus, from threads I have read - the pros keep it to a minimum. Also, by the nature of production required in a busy cafe the required ritual has got to be at a minimum.

The quick "suction" pull outs are to bring in the grind that is stuck to the side of the basket. I do not do the tamper side knock. My tamper is 0.2 mm smaller than the basket and when you nutate it compresses the grind to the side.

How could it be disruptive?

Also the tapping down is only if I do not groom to settle and redistribute a bit. So, I wont be doing that for a while.

For the coffee, it is surprising how this blend has so much of the attributes that I like. Every so often I get a 250g of fresh roasted from various places but... The journey is just starting.

Whale wrote:How could it be disruptive?

Possibly disturb the puck with vacuum pressure?

I ignore the grounds on the side of the basket. Maybe blow lightly over the puck to blow them out if I see something that has fallen down onto the top of the puck.

I'm still new to this, maybe I ought to be paying attention to the grounds on the side of the basket?

PS, I am using a convex tamper which may work better with the Vivaldi due to the nut hanging down below the screen

As far as I see it, we want an evenly-distributed and compact puck. Anything that disturbs that is not a good idea, since it will probably lead to channeling and an underextracted shot.

So, any upwards "sucking" that one might be able to achieve by withdrawing the tamper fast, or any tapping to dislodge grinds stuck to the side of the basket is, I think, likely to disturb the puck without actually achieving anything positive - even if one does then tamp again. My experience is that the more I fiddle with the puck after one tamp, the more likely I am to ruin things. And I honestly don't think that the odd grind on the side of the basket or falling onto the puck is going to do anything in the grand scheme of things, whereas trying to get rid of it by tapping could I think increase the chances of creating gaps in the puck or between the puck and filter basket, which will result in channeling and under-extraction.

My thinking is that I only need to concern myself with keeping the basket rim clean so that the PF can seal shut, and that just takes a quick wipe.

Leaving the theory aside, this has yielded more consistent extractions for me in practice, which is why I suggested it. That's actually just referring to the tapping - I must confess to never having tried the fast tamper withdrawal..... but it does strike me that it's likely to lead to a less consistent puck, even if one is tamping again afterwards.

As for tamping pressure, I have also got better extractions and consistency by grinding finer and tamping lighter - much lighter. I literally just apply finger pressure now to get a compact, level puck.

I have tried the nutating tamp on Dan's recommendation, but find I get the occasional side channeling as a result. Maybe I am overnutating . But I get on better without it, swiping to level if need be, either with a finger or a saucer or even the tamper, without any pressure and using a sweeping motion. Or if the basket is very full, with a good old Stockfleths. For more about the Stockfleth's and Dan's "Stockfleths for Dummies" which he referred to above, see Stockfleths Move for Dummies [video] You could find this really helps you get excellent results.

I also prefer a heavy tamper. Not because I need the weight on the coffee, but because I find I get better feedback on what I am doing. Likewise I prefer a short handle. I'm just cack-handed I suppose....

I do however think the tamper is probably the most over-rated item of barista equipment. Which hasn't stopped me ordering a beautiful wooden one from Les of Thor Tampers

Cheers

Mike

At the risk of repeating advice that has been given over and over on these boards:

1. It's all about the coffee. Use freshly roasted beans, not vac packed beans roasted many months ago in Italy.
2. Many words have been written about tamping and tampers. Perhaps far too many. IMHO you can get away with using just about any tamper and tamping style. Differences between convex and flat pistons are subtle, and should not make or break your pour. You do not need a piston that is sized to within a micron of the basket diameter. Get a tamper that feels good in your hand, be reasonably consistent in your tamping pressure, make sure the tamp is level, and you'll be fine.
3. I see no benefit from your "vacuum withdrawal" technique. (I won't say it. I won't say it... ) If grinds on the top lip and upper sides of the basket disturb you, brush them lightly with a finger and then gently invert the basket.
4. Downward tapping before tamping is fine, but be aware that this is an extremely effective updosing technique. I would not recommend downward tapping unless you are deliberately updosing, or you have premeasured your dose beforehand. Tapping of any kind after tamping is a no-no.