What I learned at the World of Coffee trade show
A big reason for Bugs and I to "do" a trade show stand, is to "eat our own dog food".
For World of Coffee, I built 4 coffee carts over 3 days, packed everything up, drove to Italy in a rented van, ran a high intensity mobile cafe with 4 baristas for 3 days, clean up, tear down, drive home, and then assess what went wrong.
Then we work to improve ourselves.
We're now having a big internal company discussion about everything we can change to make this easier for a customer who might try to do the same thing.
The biggest thing that went wrong were the coffee cart wheels. Half of the the brackets we make bent on the drive over. Mostly, this was caused by my having loaded 20kg of water in each cart. With each turn of the van, these water bottles slid from side to side, causing metal fatigue and bending the wheel support.
However, wheeling the carts to the location was also problematic. The wheels are great at home, where there is no dirt, pebbles, broken concrete or uneven pavement. We found that the solid-plastic wheels I had bought, had no tolerance at all for these problems. I looked on in envy at the UPS trolleys at the show, which have huge air-inflated wheels, kept at a low pressure, so that they soak up all these defects in the path.
We're redesigning our wheel brackets to be double-thickness, folded metal, at the weak points, and we're going to do extensive torture testing on this new design. We thought that 3mm thick folded, welded stainless steel would hold up, but it doesn't.
I found that the food-quality-certified silicone tube from our "catering kit" is so short, that it really limits where I can bottom-mount it on the cart. That was annoying, as I really wanted the on/off switch to be at the front, where the barista can easily access it, not shoved in tightly next to the knockbox hole. We're going to quadruple the length of that tube for all customers.
I bought two ramps to help load them carts on the truck. However, all ramps I found have bent perforations to give additional traction (for motorcycle wheels) and these perforations become barriers to the solid-plastic wheels on our cart, making it much hard to push the cart up, as well as constantly redirecting the direction, so it doesn't load straight. Again, low-pressure inflated wheels would fix this problem.
I don't usually make coffee with super-hard kenyans, roasted ultralight, and so I didn't think about the coffee grinders overheating, and seizing, with this beans. We had problems with those beans, and our Niches seized. To be fair to Niche, the problem was made much worse because these are old grinders, before Niche started using the single-bean feeder disk, which fixes this issue. If I'd thought ahead, Martin from Niche (who visited us) would have brought me a pack of those disks (I have them now, he posted them the next day) and that issue would have been resolved.
But... again to be fair, my Weber Key grinder seized 3 times with those same beans. Yes, they really are challenging, but the problem is much compounded by the 8 hours of constant use these grinders got, never resting. Not even cafes have constant demand. To work around the hard-bean problem, I had to "drip feed" beans into a already-on Weber Key grinder, and not pour the beans in and start the grinder (that caused it to seize).
And again, to be fair, the much more powerful motor on our Weber EG-1 had no problems. The Key and Niche are both meant to be home grinders, and they excel at that, but as home equipment, they do have limits.
On the positive side, Rao had commissioned 300 micron sized pore nylon inserts for portafilter baskets, and these were MAGICAL. Without these, my "solidly good shot" rate was maybe 30% with these hard beans and the Allongé recipe, but it climbed to something like almost-always-perfect with the nylon inserts. The 300 micron size comes from a tip by coffee researcher Jonathan Gagné, that the larger particles were mostly responsible for astringency in the cup. However, in my experience, these inserts are much more regular than paper, and just plain stopped channeling. I was able to grind a full 10 clicks finer on my Key, when using them, with much better puck integrity. I got many "wows" from visitors, from the Allongé coffee I made this way.
We had four coffee carts running, and the Decents performed without problems during the three days. I had two kinds of beans: light roasted from
https://www.doubleshot.cz/en that Scott Rao had organized, that pulled beautifully and consistently as an Allongé. In the past, I've used the Blooming Espresso on light roasts at shows, and it's not been a good choice, as that shot has to be very, very finely ground, and has a tendency to channel. For me the Allongé, on the Key, with a nylon filter, was easy to pull, and consistently good.
When there were issues with less-than-perfect shot pulls, such as a bit of channeling around the nylon filter, for instance, we could see it on the charts, and then taste it in cup. That was super interesting and helpful, I felt. Coffee is difficult, but it's a bit easier if you see more of what's going on.
Since this was Italy, I also had a medium-roasted bean that I could pull for those who wanted a "chocolatey espresso" from Gramos Coffee
SHOP FOR BEANS | Gramos website - this allowed me to make espressos that traditionalists recognized, but which lacked the rancid and burnt oil flavors that they are used to as "normal" for that style of bean. I used the Niche for those shots, which helped me avoid having to dial in two beans on the same grinder, and the Niche does a nice job of giving more body to espresso than the Key does.
At Scott Rao's master class in Florence, Lance Hedrick and Jonathan Gagné joined in, which is a lot of coffee knowledge for such a small audience. I set up a split screen monitor, showing Rao's slides and the Decent pulling shots live, which I thought was very helpful and something I want to do in the future.
Gagné suggested to me that a "low mass" portafilter for the Decent would be useful, as he is researching temperature profiling. A heavy portafilter helps correct for water temperature errors, but as the Decent is 0.3C accurate, we don't need that. A lighter portafilter would help the Decent have faster temperature transitions when using temperature profiling, would speed up heating, and also use less electricity to stay hot while idling. We're working on Gagné's idea now.
-john
