Hi, I just did two temperature measurements with the laser thermometer on the espresso drawn in a plastic cup to avoid post-cooling / post-heating.
I did steam heating including a minute or two with steam out of the top, as I prepared the basket in parallel. Then I fixed the EForge on the basket, filled-in and pushed the piston without any pause.

1) The standard EForge flow started above 60°C, most of the time ~75°C, max. at 80°C.
2) The fatty insulated EForge is quite the same, max at 81°C, which is within the tolerance of the job.

Before you get disappointed about low temperature just remember: It is about 14g cold ground coffee and a cold basket (20°C) and the final temperatue below the basket / in the cup is an average. Therefore the water coming down onto the surface of the puck is clearly around around 95°C or so.

The difference with the fatty EForge is not the temperature but the handling:
a) You don't need to hurry and can take your time due to slow cooling.
b) It should be easier to hit a specific temperature by surfing and wait a short while to avoid burned coffee. For me it seems to be a bit to hot for my semi-dark roasts.
c) You don't get hot fingers. This is quite a point after full preheating and I appreciate the rubber ring with the EspressoForge at this moments. I have the basket in the metal-ring sitting on the tripod and just screw the EForge onto it.
(btw: Everybody's responsible for his own safety and any kids around
and the insulation I use might be a bit too much)
Peter

I haven't even got my first machine (Caravel) in the mail and this is already making me want to order a second device when these get back in stock. Portability, yeah, that's a good excuse to get one!

Hello all,

Sorry for missing in action as I've been travelling, with the Forge+Lido combo I should mention.

Thanks Peter especially for sharing your results. I agree with your results that the Forge does need a better insulation. As per the result of steam-preheating, I do find the cylinder get very hot to hold. I am thinking a thin layer of Insulbrite may work well here. I found that material to be cheap and effective for boiler insulation.

So here're what I've found from putting the Forge into its pace during travel use:

i) The travel kit, while portable, isn't super light or compact. You do need to dedicate some luggage volume but of course it's a lot more compact than bringing a full-machine.
ii) Steam preheat is tough to execute on travel so I have to bring the blind filter for preheat
iii) Forge seems to be more sensitive to bean freshness. I noted as the beans aged (>3weeks), the crema was getting thinner and dissipated very quickly.
iv) For what it really comes down to, the EspressoForge does make some pretty good travel espresso. It isn't the most convenient device as you need to consider the clean up, the preheat procedure, the kettle and etc. But the bottomline is it passed the test as my travel kit.

Also, as the result of the trip, I noticed that some of the insulation were deformed/torn. So one just needs to be more careful with the V1 insulation material.

Here's a picture of the Forge, about 7,000km away from home.


I've attached a temp strip on the Forge. This is mostly helpful for steam preheating to avoid overheating. It never gets beyond 60-65C when doing blind filter preheat/brew.

CwD wrote:I haven't even got my first machine (Caravel) in the mail and this is already making me want to order a second device when these get back in stock. Portability, yeah, that's a good excuse to get one!

Mitch, it seems that you're safe (for now) as the Forge is out of stock now.

Hey guys, I finally pushed myself enough to make some progress. So I manage to put together a crude DIY thermofilter using JB epoxy putty.

Here's some pictures:




As you can see, I basically drill a hole in the basket to put the thermocouple through. Because I'm working with putty instead of weld, they don't flow like the weld does, and I had to knead them down into the basket. I have made a dimple and a hole so that the water is allowed to flow through a single hole on the basket. I tried to get some kind of flow regulator but didn't manage find any good one. This will do for now I suppose.

For preliminary testings, it seems to work. I've tried this on my Aurora lever, and it shows right on 93+/-1 Celsius so all good.

So moving on to the Forge, I've encountered a small difficulty because Scace protocol requires the puck to be warmed up prior to measurement. On the Aurora I just let the pf/thermofilter sit in the machine but obviously that's not viable on the Forge.

However, I had made some measurements and the early impression was the heat loss is really greater than I've imagined. I did manage to get up to 91 Celsius after the fake puck is warmed up (with steam preheating the main body to 90C). I'm still coming up with a proper protocol for measuring the temp but it does seem to give me a better idea what the temp profile is like on the Forge. It's more or less an increasing temp profile like an E61 - starts low then goes up to an equilibrium(target temp) after about 10 sec. For comparison, on the Aurora lever, you reach your peak target temp within 3 sec and decline from there.

I've previously thought that with boiling water+steam preheat, I would burn the coffee, but the measurement showed that the water got cooled quickly from 100C to 80s(once poured into the Forge) and the temp starts climbing up from there.

Will follow up after I do more testings. If you have any request of what you'd like know (within my reach), feel free to shoot it .

Update: more preliminary results - this time the trend seems pretty consistent...from cold, if I steam preheat the Forge to 90C+ as measured on the main body, once the boiling water gets into the Forge, it cools down to around 80C and it rose to about 82-85C max. If I do another test immediately after the first one, it will then rise to 90+C (I suppose that's because the portafilter ring and basket are fully warmed up). However, this scenario doesn't seem to be practical in an actual brewing... Hopefully I am wrong about this. It seems pretty odd that the temperature got cooled down so drastically even when my temp strip was showing a surface temp of 90C. And the device was steam preheated for 1-2 minutes. Not sure what gives..

No problem Dan. I agree that the Forge can make some very amazing shots without all these manipulation.

However, I have been very curious about the temperature aspect of the Forge and there's not a lot of data available (other than from Peter earlier), so I figure others might be interested. So most of these experiments were to satisfy the geeky part of me.

I did more testings this morning before going out. What I have found was, again, I had underestimated the heat loss that can happen due to the cool 'puck'. Today, instead of letting the thermofilter/puck warm up in the machine, I inserted a room-temp thermofilter into the spring lever and pulled a simulated shot. Seems like it had a significant impact and I was measuring about 85ish Celsius on the warmed up spring lever. The heat loss to the cool puck is so significant and no wonder I only managed to get 80s Celsius in my previous runs on the Forge.

So I have tried a different approach today to measure the Forge's temp. Instead of using a room-temp puck on the Forge, I let it warm up in the spring lever. Then, I steam preheat the Forge and boil the water like I would normally do. When I'm ready to pull the 'shot', I remove the thermofilter/puck from the spring lever and lock it onto the Forge.

I managed to take 3 readings using this method. 92C max for the first, 89C max for the second, 91C max for the third. All these are the max temperature and they happened during the last 1/3 part of the pull. I did cool the Forge under running cold tap water in between the 'shots', so that I can reset the Forge's temperature to room temp for proper comparison of what's expected in a normal usage.

Another observation I've noticed is, the main body(the part that holds the E61 screen, aka the grouphead) temperature is very important. If I only heat it up to 90C (green), it gave me a temp of about 89C even though I've had it on the steamer for 1 minute. Ideally I want to get it above 90C (when the temp strip turns blueish).

So the mini conclusion for today is - to brew in the conventional 90+ Celsius, just steam preheat the heck out of the Forge, and use hot boiling water. For the record, I have never seen temperature above 93C measured from the puck's perspective, even the device is heated up and hot boiling water is poured in. The showerscreen seems to help reducing the water's temperature before it hits the puck. There's so much metal and contact in the Forge that it's almost impossible to scorch your shot.

I have a Forge, Spring lever, fino kettle, and a scace. Perhaps this weekend I can run some experiments similar to Sam's to confirm his findings.

Oh Dominick, please do (since when did you get a scace?)! Thank you! That'd at least confirm if my DIY thermofilter is up to task.

The scace is on loan from a friend of a friend. I actually received it the week after Christmas to test my thermosiphon modifications but I've been so busy with moving and remodeling I haven't had the proper time to take any meaningful readings.