Siliconslave's how to make espresso thread

Soldato
Joined
1 Mar 2010
Posts
21,780
I moved to just 14g dose (rather than just filled to the brim with ground), proper size basket and realised that the 4 holes on the gaggia is on the outside. Meaning a curved tamper would have less pressure on the outside.
which holes - you mean the grouphead water holes beneath the screen are towards edge of puck ?,
I had a curved tamper, my basket is, now, convex too, maybe matching the profile, and, keeping coffee depth uniform.

actually seems an interesting mathematical problem where to locate those holes to give the jets uniform coverage of the puck area
 
Caporegime
Joined
20 Oct 2002
Posts
74,024
Location
Wish i was in a Ramen Shop Counter
which holes - you mean the grouphead water holes beneath the screen are towards edge of puck ?,
I had a curved tamper, my basket is, now, convex too, maybe matching the profile, and, keeping coffee depth uniform.

actually seems an interesting mathematical problem where to locate those holes to give the jets uniform coverage of the puck area

The 4 holes from the brass shower head, not the screen.
 
Soldato
Joined
1 Mar 2010
Posts
21,780
The 4 holes from the brass shower head, not the screen
you mean the grouphead water holes beneath the screen

still availble, compatible with a convex portafilter https://www.bellabarista.co.uk/motta-58mm-curved-base-tamper-red.html
That is dissapointing abou the tamper fit.
For previous discussion I had bought the ridgless IMS filter
which specced CORPO: Ø 60 mm per pressino Ø 58 mm
and so there might be nearly a mm in it, in conjunction with
'Motta Tamper - Curved Base 58mm (Wooden Handle) (Used As Demo) £9.66'
but would not want it much closer in case I scarred either
 
Caporegime
Joined
20 Oct 2002
Posts
74,024
Location
Wish i was in a Ramen Shop Counter

I already have a convex one as said earlier. My VST basket has a flat base, hence the original question.


What are people's thoughts on the base of a tamper, curved or flat?

I remember YEARSSSSSSSSSSS ago looking into this and my conclusion was that the difference were small and some how I ended up choosing a curved one. However, since lately I moved to just 14g dose (rather than just filled to the brim with ground), proper size basket and realised that the 4 holes on the gaggia is on the outside. Meaning a curved tamper would have less pressure on the outside. The difference between the centre to the edge in height is probably under 1mm but if 1g of coffee can have an affect on the extraction I am thinking this pressure difference would too. Especially now the puck is 20% thinner than previously.
 
Soldato
Joined
1 Mar 2010
Posts
21,780
I still didn't understand why you thought the 4 holes location might justify a convex tamper,

I was answering siliconslaves point when I said they still exist,

but, yes, I think the convex are more effective to create a uniform puck since with the non-uniform/convex tamper pressure coffee can migrate outwards from the higher pressure point in the centre, to lower pressure edges.
 
Soldato
Joined
18 Oct 2002
Posts
6,747
Location
Cambridge
Coincidentally, just had a dispatch email saying that my Niche should be arriving tomorrow! Really looking forward to it now as with each bag of beans I get, it’s 50/50 as to whether I can get a decent shot with the iMini :)
 
Caporegime
Joined
20 Oct 2002
Posts
74,024
Location
Wish i was in a Ramen Shop Counter
Coincidentally, just had a dispatch email saying that my Niche should be arriving tomorrow! Really looking forward to it now as with each bag of beans I get, it’s 50/50 as to whether I can get a decent shot with the iMini :)

Have you got a set of scales? I find now I am getting MUCH MUCH better coffee with the Niche, partly because it is a better grinder but partly because every shot now I am putting in accurate weight of coffee. Actually so much so I might upgrade my scales, only using some £15 ones but I find that it isn't that accurate, it lags and sometimes putting a single bean can make it move the numbers, sometimes it doesn't.

My coffee is getting to a point where it is in the ball park of good but now every little rough edges I want to iron out.
 
Man of Honour
OP
Joined
11 Dec 2002
Posts
10,808
Location
Darkest Norfolk
Have you got a set of scales? I find now I am getting MUCH MUCH better coffee with the Niche, partly because it is a better grinder but partly because every shot now I am putting in accurate weight of coffee. Actually so much so I might upgrade my scales, only using some £15 ones but I find that it isn't that accurate, it lags and sometimes putting a single bean can make it move the numbers, sometimes it doesn't.

Arr the scale problem - seems finding a fast, accurate and waterproof scale is a real challenge - very tempted by a perl but for now i'm just using a cheap jewelry scale and trying to be careful with it. Although this is the second version as the first had half an espresso poured over it which apparently the screen doesn't like!
 
Caporegime
Joined
20 Oct 2002
Posts
74,024
Location
Wish i was in a Ramen Shop Counter
Arr the scale problem - seems finding a fast, accurate and waterproof scale is a real challenge - very tempted by a perl but for now i'm just using a cheap jewelry scale and trying to be careful with it. Although this is the second version as the first had half an espresso poured over it which apparently the screen doesn't like!

The thought of dropping £130 on a Pearl is stupid but now I can see why, if they do what they claim they do.
 
Soldato
Joined
18 Oct 2002
Posts
15,711
Location
North Wales
Decided to repair the Silvia for now, still plan on upgrading the machine but it can wait for now.

Removed the old boiler in preparation of the new one, actually wasn't as bad as I thought it was going to be in there (in terms of limescale etc):
z9EE1s1.jpg
qpqBQSI.jpg

Machine is dated 2011, so not too bad I guess.
 
Man of Honour
Man of Honour
Joined
3 May 2004
Posts
17,682
Location
Kapitalist Republik of Surrey
On the subject of old machines...

Just checking in. Haven’t been on the forum for ages. The Gaggia Classic I got on recommendation on here back in... 2008 is still in daily service! I used a convex Motta tamper at one point but it just seemed to consistently make the water rush through the middle of the puck, so I got the base ground flat in our workshop and it’s been great.
 
Soldato
Joined
1 Mar 2010
Posts
21,780
Removed the old boiler in preparation of the new one
yes they are well engineered
did the element show a short with a meter ? in retrospect, maybe you tried, the rcd doesn't trip with just element disconnected


If the grounds are level there shouldn't be a difference in pressure across the tamper
see this thread - https://www.home-barista.com/espresso-machines/tamper-bottoms-flat-or-convex-t24-20.html
which discusses reduced coffee density at pf edge


learned something from that - the convex motta I have, has 1.6mm height on the convex point, so, apparently a usa, not eu, curve.
 
Soldato
Joined
17 Jun 2007
Posts
9,273
I dunno where I can go wrong.

Fresh beans, check.
Correct weight, check.
Good grinder, check.
VST basket, check.

The only variable I can’t control is the pressure and the temp in the machine as it doesn’t have PID but everything I have control over I ticked the box. I know it’s not be all and end all but the duration isn’t too quick or too long, it’s about 25-30s.


If its spritzing then chances are your not Tamping correctly, or its uneven distribution

Not checked into here for a while sorry if youve sorted it
 
Last edited:
Back
Top Bottom