Hello everyone, i am a new member to the forum and fairly new to the espresso world. I have invested in a basic home set up and ive done a lot of reading about extraction and i am familiar with what is expected from a good shot. I know what yield, ratio, dosages, etc etc are so feel free to use that terminology. Ive also watched a lot of YT tutorials trying to perfect my technique. But there are two problems which happen again and again and i cant seem to find a way around them. But lets start with the basics.

Set up:
Sage Duo temp pro (bought new)
Eureka Mignon Manuale (older version, bought second hand but new burrs)
2in1 distributor and palm tamper

Now to the problems:
A) I am using 7 days old coffee from a speciality roaster, a Colombian blend, medium roast, and i get constant channeling at the same place of the puck. I removed the shower screen and cleaned thoroughly, i also back flush with water at the end of the day, so everything looks to be clean. I tried grind finer and lower the dosage (usually i go for 18gr) to 17gr because shower screen was touching the puck when i used 18gr but didnt saw any improvement. At 17gr the hole appears to be bigger. I will try to run a test and upload pictures. Its worth mentioning i am single dosing, weighing both beans and grounded coffee and ive only have a retention of about 0,05-0,1 so my grinder appears to grind consistently. I lightly shake the grounded coffee inside my dosing cup to destroy any clums and use the distribution tool and tamper to even the puck before brewing. There are no visible flaws.

B) coffee comes scorching hot, i assume because it cant properly cool down since its channeling. The machine is notorious for pulling cooler than normal shots so that looks weird to me. I usually run some water through the empty portafilter to bring it up to temp, especially if just started the machine in the morning and dont have time for everything to properly warm up. Sage Duo temp pro has no indicator or setting for brew temperature.

Ive done a lot of research but cant seem to understand what the problem is, so your help will be gladly appreciated.
Thanks in advance!

If you get more flow on one side of the basket, the tamp may not be level - or the group.

A photo of the problem could help.

How many seconds does it take to pull the shot from the time you push the button? How many seconds before coffee begins to come out?

I haven't moved the machine so the group head should be flat, as in the past I was able to pull perfect shots. As for the tamp, since I use a distributor and palm tamper I can't really understand how the tamping might not be flat but I'll try to be more careful.

The shot takes approximately 28secs and coffee starts flowing around 10-11 seconds. The problem is it get blonde/white very fast, I only get a small portion of dark red before it starts channeling and the final outcome is just boring. 2,5:1 ratio


****UPDATE***** I looked online for this particular problem and appears everyone has it with the sage DTP as it only has one hole which pours water underneath the shower screen and it's off center to the right (at the exact spot where I am getting the channeling). People say that if you have coffee on the pressure of the puck should distribute the water evenly. So should I grind coarser and up the dose?

Tried to grind coarser and up the dose to 18,5gr. The channeling hole is significantly smaller, but still there. The flow is consistent although I still only get minimal dark red coffee which turns immediately to white. It doesn't splash though. Taste was noticeably worse with this setting though.

Tried to grind coarser and up the dose to 18,5gr. The channeling hole is significantly smaller, but still there. The flow is consistent although I still only get minimal dark red coffee which turns immediately to white. It doesn't splash though. Taste was noticeably worse with this setting though.

Are you by chance doing any WDT (Weiss distribution technique) to your basket? This could help a good bit along with actually grinding finer. You mentioned the shots are taking around 28 seconds with the first drips coming around the 10 second mark. I'm not familiar with your machine but I'm assuming it has a stock pre infusion programmed in? Are you doing a 1:2 ratio, 18.5g in, 37g out? If so, 18 seconds after the first drip to get your full shot is pretty quick and it could help to go slower. My advice would be to grind finer, look into WDT, and not worry about the total extraction time falling within a 20-30sec window. For one of the coffees I use, I do a 50 sec total extraction time which includes a 10 sec pre infusion. All depends on the beans and what they need.

I wonder if you have enough head room between the puck and the shower screen? The coffee swells when water is introduced, so there needs to be some space to allow for that. Perhaps try a lower dose (16g?) and a finer grind. I agree with ping279 that 18 seconds from first drip to a 1:2.5 ratio sounds way too quick.

apostolis14 wrote: ****UPDATE***** I looked online for this particular problem and appears everyone has it with the sage DTP as it only has one hole which pours water underneath the shower screen and it's off center to the right (at the exact spot where I am getting the channeling). People say that if you have coffee on the pressure of the puck should distribute the water evenly. So should I grind coarser and up the dose?

If you have a problem with the water distribution you may find using a puck screen will help distribute the water more evenly but puck screens are thick and it may require you to dose down or get a bigger basket.

Which comes to the next point the basket/PF. I don't know what sort of PF/basket you have but if you have a pressurised one you may want to consider looking for a non pressurised PF baskets and preferably a bottomless portafilter (if you don't have it already) pressurised basket won't be the best for distribution and it's sort of a brute force method to ensure your getting the right pressure but you do sacrafice a lot in doing so. A non pressurised will be harder to dial but the rewards are worth it.

The DTP has 15 bar of pressure which is a lot and it may be too much pressure causing excess channeling. On machines like these a way to decrease the pressure is installing a dimmer switch in the pump. This way you control the power going into the pump which controls the pressure coming out. It's not for everyone but a mod like this is probably more straight forward then you think and puts the machine on another level. Lance Hedrick has a video doing the mod on the bambino and you might want to check it out since it's a sage/breville product it may be similar on your machine.

Thanks everyone for the suggestions. Indeed the machine has a stock pre infusion which I always considered part of the total brewing time. I am doing WDT and I am using a non pressurized basket so that's not the problem. It looks like the room between the puck and showerscreen is enough, when I lock the pf on group head they are not in contact. A few things worth mentioning here:
a) this wasn't always the case with my shots, started about two to three weeks ago and it drives me crazy, although it has happened with coffee only from one roaster which leads me to believe it might be something from their side. Getting new beans in a few days and will try. In the past I've used doses of 18-18,5 with consistent amazing results. Different beans though.
b) indeed I dosed lower and grounded finer, 17,5gr ,1:2 ratio , 38sec, same exact channeling hole , but flow was consistent except from colour. Shot tasted good but a bit harsh. When removed pf the puck was stuck on the showerscreen.
c) the problem started shortly after I removed the showerscreen for cleaning. I installed correctly and I've tried tightening/loosening the bolt in case it warps it but nothing changed
d) Tried 16,5 , finer grind, machine chokes for the first 2-3 seconds, then delivers 1:2 at 36 sec , clearly channeling, see photo of puck afterwards, it's horrible. Same hole placement, along with a few others.