Cafelat Robot User Experience - Page 409

A haven dedicated to manual espresso machine aficionados.
jpender

#4081: Post by jpender »

vladgiurgiubv wrote:@Jonk: Thanks a lot!
An unrelated question: do you have a preferred dose of coffee in? I'm only doing 19g in, but don't have any particular reason to do it like that. Did you find you need to tweak your dose?
For the same shot ratio/time, a smaller dose means you can grind finer. I think that affects the way the coffee tastes, or maybe I'm imagining it. For sure you can pull shots in the 14-20g range no problem.

The Robot manual says 10-21g. But the smaller doses (below around 14g, depending on coffee) can't be tamped with the stock tamper because the pucks sit in the tapered bottom of the basket.

rwang

#4082: Post by rwang »

Currently have a HX machine but interested in dabbling in manual machines and strongly considering the robot given the strong support from its users.

I have read some recommend a flair 58 over the robot for light roasts given the better temperature control. I pretty much only use light roast for espresso, can anyone comment on their experience with pulling light roast shots on the robot?

Jonk

#4083: Post by Jonk »

If you're happy with the results you get with a Niche I'm guessing your light roasts are kind of medium light. I don't think you'll have a hard time with those on the Robot, but you might want to preheat a bit.

For the very lightest roasts available a different grinder is in order in my experience. Still, it's not actually the Robot that would be limiting.

vladgiurgiubv

#4084: Post by vladgiurgiubv »

Jonk wrote:Wipe the gasket, that solves it for me. So I guess it's actually more initial friction.
Unfortunately this did not work for me. In fact the friction was so much that the gasket got damaged and could not use it anymore as it was leaking no matter what I did. I put the new gasket in and now I don't have the leak anymore. Unfortunately there is very little metal below the gasket to properly heat the piston without water touching the gasket. I see no long term possibility to do preheating without any problems. I wonder why it didn't work in my case and it works with your Robot.

The only simple and wear-free why I see is by putting a seal in the basket to significantly reduce the flow of water and do a dummy shot (without coffee) for preheating (the gasket does not get wet but the piston gets hot) - like Paul did on cafelatco instagram a couple of months ago. Unfortunately I don't know what seal he used, so I'm out of ideas.

Jonk

#4085: Post by Jonk »

Sorry to hear that. As far as I know I'm not the only one doing it this way, but every basket is unique - perhaps yours is tighter than the 3 I've used.

vladgiurgiubv

#4086: Post by vladgiurgiubv » replying to Jonk »

I guess it's unlikely. Most likely is that I'm doing something wrong, but can't imagine what. I've tried preheating, wiping the seal and then extracting -> leaks. I've tried cleaning, lubing the seal, then preheating, no wiping and then extracting -> leaks. I've then tried wiping everything, lubing the seal, no preheating and then extracting -> leaks. So I changed the gasket. I'm afraid to do the preheating, wiping the seal and then extracting with this new seal, because it's the only one I have left. I tried it once, it worked, and the coffee tasted great, but I'm afraid to do it on a regular basis, also because if the seal is not lubed it's much harder to insert and rotate the portafilter.
When I preheat the coffee is much more to my liking, so I guess I have to do it. Just extracting it longer does not give the same taste as normal extraction with higher temperature.

jpender

#4087: Post by jpender »

vladgiurgiubv wrote:Unfortunately there is very little metal below the gasket to properly heat the piston without water touching the gasket...

...The only simple and wear-free why I see is by putting a seal in the basket to significantly reduce the flow of water and do a dummy shot...
You don't need a lot of metal in the water for preheating to be effective. Just submerging the piston a millimeter is equivalent to doing a dummy shot (or a real shot).

You can buy more seals and replace it periodically. That's what I do, install a new seal every 8-10 months. They are inexpensive.

Or, if you're good with tools, make a non-metal piston out of food safe material. Then piston preheating is unnecessary. That's what I plan to do.

vladgiurgiubv

#4088: Post by vladgiurgiubv »

Does preheating with the pressurised filter work, i.e. is the hole small enough? I imagine you can fill it up, put it in the robot and let the water flow out due to the weight of the arms. During this time you can prepare a second (professional basket) with coffee.

jpender

#4089: Post by jpender »

Others have used a pressurized basket for preheating the piston, just like you are thinking. How well does it work? I've experimented with preheating the piston by blocking the holes in my professional basket with a little round silicone disk. I filled it with boiling water and then let the arms hang under the force of gravity. That's similar to what you are considering.

What I found was that the effect was modest as compared to preheating the piston in a cup of boiling water. I tried pouring boiling water into the basket, dumping it, pouring again, and then using that for preheating. That helped but it was still not as good as soaking the piston in a cup of boiling water for a couple minutes.

Might as well try it though. Maybe it will be enough for your needs.

Ken5
Supporter ★

#4090: Post by Ken5 »

vladgiurgiubv wrote:Does preheating with the pressurised filter work, i.e. is the hole small enough? I imagine you can fill it up, put it in the robot and let the water flow out due to the weight of the arms. During this time you can prepare a second (professional basket) with coffee.
I preheat with the pressurized basket and I find it works very well. Never tried dropping the piston deep into a cup of boiled water to compare though. I find the piston does get hot enough that it is hard to keep fingers on the piston for longer than a second.

What I do is fill the pressurized basket higher than I do the regular basket when making a shot, usually about 1/16 an inch from the top and then immediately after locking in the portafilter I loop a string from claw to claw to keep the arms up. What happens is there will be a few drips from the basket and then it stops due to the finger on a straw effect. Then I grind my beans and when I am done the piston is very hot. Can get it a little hotter by doing it a second time as the piston does not suck out as much heat the second time, but is not really needed.

I used to let the arms drop rather than tie them up, but the water lasts much longer when tied, and I figure that the temperature might stay hotter without the loss of volume.

Will have to try the cup technique to see how it compares.