been testing this setup for a while with brewed coffee and I did have some problems (of my own making). Once I stopped overthinking it and doing my “own” thing, the problems disappeared and I started getting results. Which show, I brew my coffee pretty much perfectly, something I had guessed already. I tried a few things and was able to brew imperfectly in both directions…to low/high an extraction % and the taste differences seemed to correspond.

With Espresso, I was a little more sceptical as Rodney from BB mentioned that they had not been able to get results anywhere near what they should be getting. I found this interesting and thought, OK this week I am going to try espresso. I had intended to try it yesterday and couldn’t log into the app, which had logged me out after a phone update. Plus horror of horrors, my email wasn’t recognised for password reset….none of them? The problem…I had never made an account, just used the app as a guest…and once I remembered this, I was “in like Flynn”. More good news, all my previous results were still saved in the app! Note to self, create an account some time.

Entered the app, switched the R2 refractometer and the TI scales on, Bluetooth immediately connected them to the app on. I quickly zeroed the R2 and was ready to go. I switched to espresso and started inputting to the app, I had not RTFM, but had learned my lesson…don’t fight the app.

Bodum espresso glass on scale (touched app to auto enter cup weight
18g of beans on scale (touched app to auto enter weight

There were other fields, but rather than mess with them…like shot ratio etc.., I thought, reasonably, the only data I have that makes sense is the weight of coffee and the weight of cup…everything else is down to the machine and when it auto releases. So bunged the scales and glass on the Evo 2 (my shot auto release pressure is at 7.4 bar). Set the app to the next option (record brew or shot process), touched app button it to tare the scales, pulled lever down and I was away.

The first drop hit the shot glass and the scale started recording and timing the entire process in the app. at around 1g per second, out came my espresso. At 35s the Evo2 auto released and the process ended. The scales of course didn’t stop and I didn’t think to stop them for a while. No problem though as the Evo not only had my shot time, but my preinfusion time as well.

Moved to analyse/show results and up came the familiar 3 by 3 grid. I figured I now needed to put the Espresso in the R2 for refractometry analysis. I want to make the point here, the R2 is absolutely the easiest refractometer I have ever used!

This is probably the only slightly involved bit for me as the sample has to be at room temp and I like my espresso hot. So this is how I do it. I use a printer refill syringe with it’s needle and a small glass dish they use for marmalade at posh hotels. The syringe allows me to take an espresso sample under the surface of the crema (saves me having to mix the crema in first. It also allows me to take a small sample, just enough for the refractometer and squirt it into the glass dish. This immediately brings it to room temp and I suck it back into the syringe (no bubbles) and squirt the blob onto the R2 sight glass. I press the R2 button and it starts taking readings (3 I think), I look dpown at the app and am gratified to see this:

Apparently 20% is meant to be perfect…so I wasn’t far off. I suppose I could tweak the grind, or the release time but to be honest it tasted great. As for tweaking grind or release time, not 100% sure what effect that would have, so I need to test a few more espressos, in case this was a fluke and then over the next weak or so, test what does what and by how much?

Here’s a bit more data it created on my shot….the time I input myself from the Evo…there is no place to add preinfusion time. Something they need to add to the app, as well as (for me), which machine, not just which grinder. For this I used the T64 (with SSP HU) from BB.

Then finally the equipment I personally use. Note the syringe for printer cartridge refilling and the glass dish.

Final thoughts, the software is good and does all the critical things well, but I think could use some tweaks, all cantered around recording grinder and machine better.…so I am going to feed back to them in the hope these can be included in a future update.

Hopefully you found this lengthy post interesting, I did, because I had never used a refractometer for espresso before..