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SDTP and Pro Grinder - How fine do you grind?

11K views 19 replies 10 participants last post by  ashcroc  
#1 ·
Hi, I'm looking for advice from people with the same setup really.

I recently bought a Smart Grinder Pro to accompany my SDTP espresso machine. I've probably tried about a half dozen different beans, couple of dark roasts and the rest medium. I'm finding that unless I only use about 2kg of tamping pressure I have to set the grinder to 20+ to get around a 30 second extraction. That's with the double espresso basket, the single seems to provide only a trickle of water regardless (I'm using single wall).

Is this normal for this machine or could there be a problem with the pump? I cleaned the part in the group head, it was half blocked with ground coffee, but this didn't make much difference.

I'm still learning to use the machines but can get decent coffee most of the time. I just wonder if I could be getting more from the coffee with a finer grind if the machine could take it. Anything less than 10 chokes it!
 
#2 ·
I'm having a similar problem with the same setup, so I don't have an answer yet.

I've just moved to a sdtp from an old gaggia classic & admittedly I'm only on shot no3, but I'm not having much luck [emoji23]

1st attempt I ground at 8, (17.5g, double basket) which was fine for the gaggia, but on the sage I only got a trickle before the machine auto shut off [emoji23] it did taste good though, surprisingly [emoji50] not that hot though.

2nd attempt, same weight of grounds but I ground at 10, I got a bit more coffee out (19g) & again it was very nice, but not a double shot & the machine shut itself off. I would've thought it would be over extracted if the machine shuts off?

3rd attempt, same weight, size 12. This time it took almost exactly 30 seconds & I got 30g espresso, I expected that to be pretty much perfect, but it was bitter [emoji849] it was hotter though, I submerged the portafilter in a bowl of boiled water beforehand, it doesn't heat up like the gaggia did

Not sure what to try next time [emoji23] but I'll post an update [emoji106]
 
#3 ·
what dose of coffee are you using? this can impact on the flow of coffee as well as the grind size. Use the razor tool that came with your coffee machine

What beans are you using are they fresh roasted or stale supermarket beans? fresher beans coarser setting- finer grind setting as they the begin to stale

I have a sage barista express and a smart grinder pro, I find when trying to dial a bean in on the smart grinder pro, I usually start around setting 14 and work from there.

Every bean is different and needs different grind settings as it ages, But I am usually in the range of 9-13 on my smart grinder for espresso and have never needed to go lower than that. But my grinder is newish about 2 months, so I am as time as the burr wear I will need to use finer settings or move the upper burr adjustment ring from 6 to 5.
 
#4 ·
The razor tool is a very good idea on the Barista Express so is very likely to be on the DTP. The height of the dose of grinds does matter. The grinds expand when the water goes in so too high is a very bad idea unless it's being done within limits on purpose. Too low has other problems usually relating to rather soggy pucks.
:(
The razor tool on the DB is the pits and doesn't work out well at all.

While it's a pain home espresso machines need certain steps to be taken to get consistent results. One of those is a consistent weight of grinds. The other from that is consistent shot time and output. The razor tool can give a ball park weight. Handy when the grinder setting is being changed as finer grinds take up less space so usually need and increase in the weight used.

Best simple option on tamping is as hard as you can manage and keeping it level. If out it's possible to correct tamps but not and ideal thing to do just a better option than leaving it well out of square.

So scales are needed. A good option is 1kg ones that read to 0..1g. Not too small as ideally they need to be able to weigh the entire portafilter balanced on them to check the weight of grinds that is in it. Mine have 130mm dia platform which is fine for that and if I move the portafilter around on them a bit the weight doesn't change. 100mm square is probably ok. One idea of the razor tool is to avoid weighing the grinds - always put a bit to much in and razor off excess.

Still need scales though really. So the first thing to do is to adjust the grinder to give some ratio of grinds in to weight of the shot that comes out within a certain time. One that gets mentioned a lot is 30 secs and 1 in to 2 out. A ratio of 2. Also that a single is either 25 or 30ml and a double 50 or 60. 1ml weighs 1g so weight can be used to check that if needed. It's more than accurate enough. Later some one might want to taste other ratios. Usually for home use those might range from 1.5 to 3 shot sizes varying accordingly still at 30sec or even that could be adjusted. Eg the 1.5 ratio might be best obtained by reducing time and the amount out. The high ratio by grinding for it and keeping time the same. The idea is to get a taste that the drinker likes and varying this aspect will alter taste. Commercially speaking ratios may go well over 4.

Every time the grinder setting has been changed the previous setting's grinds must be got out of the grinder and thrown away. 2 secs is likely to do that on most of them. The Sage grinders don't retain much actually but if they aren't got rid of it will mess tuning up. On those I always finish up an adjustment by going finer to take out any play even when I make a coarser adjustment. When setting finer one mark of adjustment seems to be ok, if more than that run the grinder while making the adjustment. Some makers will state that the grinder should be running when ever an adjustment is made. The danger is going finer though - using the adjustment to crush the grinds from the last setting.

The last aspect is that small adjustments can be made by altering the dose of the grinds that go in. Less will increase it and more will decrease output. Too low tends to leave a messy puck that may not extract consistently and too high can reduce extraction resulting in coffee that is weaker than it could be because a coarser grind needs to be used to get a ratio. Taste will change as well. One guide I used a lot on the single basket on the BE was very slight signs of the hole in the screw that hold the shower screen in place on the puck. It's fiddly finding it, increase the dose in steps of say 0.2g until it appears and then back off to see if it goes, use it there or go back up again. Sometimes the puck stuck, another 0.2g fixed that. If very distinct signs of the hole can be seen on the puck there is very probably too much in.

John

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#5 ·
le said:
2nd attempt' date=' same weight of grounds but I ground at 10, I got a bit more coffee out (19g) & again it was very nice, but not a double shot & the machine shut itself off. I would've thought it would be over extracted if the machine shuts off?[/quote']

I've only had the machine shut off a couple of times when making espresso and it was normally at somewhere after 40 seconds. It shut off while I was descaling at approximately 450ml intervals when flushing so I'm not sure what causes the actual shut off. I guess if it's pressure related you could get over extraction prior to it shutting off?
 
#7 ·
Good tips folks [emoji106] thanks. I always weigh my beans before they go into the hopper & then I weigh them when I pour into the portafilter. It's amazing how few I seem to lose considering how long it takes to clean the grinder after a couple of weeks [emoji23]

I also use a cocktail stick to break up any clumps then I bang the filter on the worktop to level the grounds before tamping. I've tried the razer but I just seem to make a mess & lose a load of grounds. I don't think I'm overloading the basket, it never sticks in the head & I see no impression from the screen on the puck.

Best results I've had so far with the sdtp is to grind 18g on 14 (never ground courser than 10 on my gaggia) & then I get roughly 30g espresso in 30/35 seconds.

Still slightly bitter but that could be the beans, since I've been without an espresso machine for a while I've been using Momentum Espresso Blend because I can get it from Sainsbury's, they've had surprisingly decent roast dates recently, I need to get some more from Crankhouse or Rave & see how that works.

So I'm getting there [emoji106] I don't like that the filter doesn't really heat up though, even with the glass preheated it's not hot enough & presoaking the filter in a bowl of boiling water is a faff [emoji51] need to get a thermometer & see if it's actually up to the temp it's supposed to be
 
#8 ·
dunc said:
I've only had the machine shut off a couple of times when making espresso and it was normally at somewhere after 40 seconds. It shut off while I was descaling at approximately 450ml intervals when flushing so I'm not sure what causes the actual shut off. I guess if it's pressure related you could get over extraction prior to it shutting off?
Yeah I presume the shut off is a pressure thing, it hasn't happened since I started grinding a bit coarser anyway
 
#9 ·
Not sure what happened to the post I wrote yesterday and haven't had a chance to get back until now.

what dose of coffee are you using?

I'm using the double basket and changing the time depending on how coarse it is. I've used the razor but mainly using the silver ring around the tamp as described in the instructions for the machine. I'll switch to using the razor every time.

What beans are you using are they fresh roasted or stale supermarket beans?

I've bought beans from a local roaster, some from Bean to Door and some Nota by Bailies Roasters from a local coffee house. I got the best results from the Nota, they were roasted about a month prior to me using them. The Bean to Door House and Brazil were about 4 days from roasting when I started using them. I didn't get great results from these, could be my technique or just that they're not my cup of tea! I did try some supermarket beans after I'd wasted about 100g of the first beans I got choking the machine! They allowed the finest grind but that was still 14.

Best simple option on tamping is as hard as you can manage and keeping it level.

When I do this on anything less than 20 it takes 40+ seconds to get 60ml of coffee

So scales are needed. A good option is 1kg ones that read to 0..1g

I ordered scales yesterday after reading your post, I think they are actually 600g so hopefully that'll be OK.

One that gets mentioned a lot is 30 secs and 1 in to 2 out. A ratio of 2. Also that a single is either 25 or 30ml and a double 50 or 60


That's what I've been aiming for, double basket and a 60ml shot. I'll be able to measure this more accurately when the scales arrive.

Also I ordered a tasting pack from Rave last week and it arrived yesterday. I started with their Signature beans and at 15 on the grinder, even with light tamping it took 40+ seconds to get to 60ml. It tasted pretty average but since then I've been making the grind coarser. The last cup was 22 (jumped from 20) on the grinder and I tamped as hard as I could. The coffee tasted good, a big difference to when I started, lots more flavour. The Rave beans were roasted on 01/11/18.

I'll play about with the settings some more when I have the scales and report back.

Thanks for the advice so far
:)
 
#10 ·
dunc said:
with light tamping ... I tamped as hard as I could.
I used to try varying tamping pressure but it's a variable you can't reliably control, so instead I now tamp until there's no more movement and adjust grind to get the target flow rate.

I'd be interested to know whether anyone else has found if hitting a 1g per second grind rate in the SGP is a reasonable guideline - it seems to be a decent rule-of-thumb for the beans I've used so far to get a decent flow for a 30-second extraction (i.e., lower g/s means finer grind and slower flow, higher g/s means coarser grind and faster flow).
 
#11 ·
Hi,

i am using the same set up and my settings on the grinder are Grind size: 12 , grind time is 13.4 seconds and I am using single wall double basket. Espresso shot is longer around 60ml and all happens in around 22-25 seconds. If I want to do two single shots I use same grind setting but increase grind time to around 16-16.4 seconds and brew times remain same 22-25 seconds including pre infusion. My coffee tastes great and makes my day everyday.
Beans Lavazza Rossa , best to my like, reach crema and chocolate taste, ☕
 

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#12 ·
Just had my first coffee with my new pro grinder. Used 18g of ground coffee from setting 12.

I timed from turning the dial and nothing came out for 20 seconds. I carried on to 50 seconds.

I got around 32g of coffee that tasted ok but I'm guessing the grind is too fine with the fresh beans?
 
#13 ·
Weymouth said:
Just had my first coffee with my new pro grinder. Used 18g of ground coffee from setting 12.

I timed from turning the dial and nothing came out for 20 seconds. I carried on to 50 seconds.

I got around 32g of coffee that tasted ok but I'm guessing the grind is too fine with the fresh beans?
If anything tasted off with it, what would you say that was?
 
#14 ·
MWJB said:
If anything tasted off with it, what would you say that was?
Maybe slightly bitter but I add sugar and milk so maybe I should test just drinking the espresso!

I'm going to try again tomorrow with a higher grind setting say 15 stop after say 40 seconds. I remember someone saying they dont time from turning the dial they time after around 10 seconds or something like that.
 
#16 ·
Weymouth said:
Maybe slightly bitter but I add sugar and milk so maybe I should test just drinking the espresso!

I'm going to try again tomorrow with a higher grind setting say 15 stop after say 40 seconds. I remember someone saying they dont time from turning the dial they time after around 10 seconds or something like that.
Don't kill the shot by time, depending on how much you pull, a good shot could be anywhere from 20-60s. Time from turning the knob, always.

Go a shade coarser & aim for 54g out.
 
#17 ·
I used to have a Sage DTP (but not the Sage grinder) and got good results. Just a thought, which you may have done but not clear. You say you cleaned the group head but did you remove and clean the shower screen? It's really easy to do on the DTP with an allen key. Apologies if that's obvious and you've done it. Good luck with getting there.
 
#18 ·
MWJB said:
Don't kill the shot by time, depending on how much you pull, a good shot could be anywhere from 20-60s. Time from turning the knob, always.

Go a shade coarser & aim for 54g out.
I thought the consensus was 2:1 so 18g in and 36g out
 
#20 ·
Weymouth said:
I thought the consensus was 2:1 so 18g in and 36g out
A 2:1 ratio can work with some bean but you may find a longer (or indeed shorter) ratio works better with others. There is no right or wrong, just what you prefer.
explains things better than I ever could.