Coffee with bottled water

Project history

  1. old posting: 'roast only' on the Bonaverde - Aldo Parducci
  2. current posting
  3. next posting: 'roast only' on the Bonaverde - Familia Alfaro


Up to now I have used tap water with a filter for my coffee experiments.
According to the water plant the water should be very hard but be only slightly above Ph neutral.
I always had the issue of always having an acidic taste.
Some coffee cups had a very balanced acidic taste, some where so strong as to be undinkable.
Especially freshly roasted coffe that was not given any time to release trapped CO2.


Now I experimented with using cheap bottled water insted.
Absolutely no sour taste anymore. Roasted the day before and even freshly roasted (with all the CO2 still in there and ALYWAYS tasting distinctly sour before) it tasted like a good cup of coffee.

Sadly it contains 500mg Ca/l+64mg Mg/l=>84,86dH and thus will just about kill the machine with scale if used often.


 Let's have a look...
The bottled water was from REWE "Aqua Mia Still" from the Alwa Spring in Sersheim.

There is a nice comparison of German bottled waters here. It has pH values (the content only lets you calculate hardness)


The water plant says, we have 23.1mg/l.
The bottled water says, we have 29.0mg/l
0mg/l is perfect
effect: in high temperature/pressure this creates hydroloric acid thatg eats away on metal.
There is nothing I can do anything about this except maybe carbon filtration.
But I don't care enough about this minor effect to do that.


The water plant says, we have 7.57pH.
The bottled water says: nothing
Water #2 says: nothing

7.0pH is perfect,
6.5-7.5pH is acceptable
effect: abovr 7.5pH this causes excess scale

Next steps: I ordered a digital pH and TPS meters from China for less then 2eur.

Hardness (Calcium only)

The water plant says, we have 75,8mg/l of Calcium
and a total hardness (considering not just the Calcium) of 12.5°dH or 2.19mmol/l
The bottled water says, we have 500mg Ca/l+64mg Mg/l=84,86dH

7°dGH/68mg/l is perfect
17-85mg/l is acceptable (first source).
8-12 °dH is acceptable (second source).
3-7 °dH is acceptable (third source).
Above 85°C this forms scale.
High hardness makes coffee go bitter quickly.
Low hardness supresses the taste of the coffee.

Here is a nice calculator between °dH, mg/l of Calcium-Oxide and ppm CaCO3,...
Or you calculate °dH = 0.1402*[Ca in mg/l ] + 0.2307*[Mg in mg/l ]
Or mmol/l= [Ca in mg/l] / 40 + [Mg in mg/l] / 24,3 .

Sodium (DE: Natrium)

The water plant says, we have 10.2mg/l.  But ADD what the water filter releases.
The bottled water says, we have 18.0mg/l

10mg/l is perfect.
Anything near that level is acceptable.

The problem may of cause also be that the water filter with my very hard water (12.5°dH or 2.19mmol/l) releases enough sodium (DE: Natrium) to exceed 10mg/l.
The original water already has 10.2mg/l and is thus at the brink of the acceptable level.
Above 50mg/l this seems to cause a sour flavor. (Very low sodium levels seem to cause sweet flavors. That sounds very interesting as it's a taste I generally like.)

TDS=total dissolved solids

The water plant says, we have 75.8mg/l of Calcium + 7.3mg/l Magnesium + 10.2mg/l Natrium+1.7mg/l potassium (DE: Kalium)
= 95mg/l  I'm not sure I did this calculation correctly and am not missing anything.
The bottled water says, we have 500+29.0+64.0+18.0+5.0=616mg/l

150mg/l is perfect
75-250mg/l is acceptable.
low=overextraction, tannic taste (DE: Gerbsäure), dry mouth
high=mineral taste, overextraction

Total alkalinity

The water plant says, we have TODO
The bottled water says: 1130mg/l of Sulfate + 414.0mg/l of Bicarbionate (DE: Hydrogencarbonat)
TODO: I need to refresh my chemistry on this topic.

40mg/l is perfect.
Anything near that level is acceptable.
effect: high=gum up outher layer of coffee and cause uneven extraction. Also scale buildup.



Setting up an OpenHab with a Homematic CCU2

Project history

  1. Previous project: name with link
  2. old posting with link
  3. current posting
  4. next step
  5. Next project: designing a chain link tool library


 I want to:
  • meassure the energy consumption of an air dehumidifier that I have running in the hobby workshop.
  • Meassure moisture, temperature and maybe even CO2 around the house.
  • Control the heating via my Google Calendar (because it shows when I'm away).

Chosen hardware:

  • Homematic parts for energy consumption and heating. 
  • I could have chosen a DIY alternative for the Homematic CCU2 but that was too much DIY for a first step that already involved way too many things I was not yet familar with.
  • Alternartive parts for energy consumption that are not completely DIY (safety) are not fully supported by EasyESP yet.
  • EasyESP on ESP8266 with various sensors and actory via MQTT at a later point.

Setting up OpenHabian

HOWEVER, do NOT edit anything in the openhab.config except maybe the Wifi password.
Else it will not boot.
(Either that or I had a broken flash the first time.)

Setting up Homematic with OpenHab

There is a very nice tutorial, that I was following.
Sadly there is one thing it is missing out on.
The CCU2 has a firewall-setting in
Einstellungen->Systemsteuerung gibt es einen Punkt “Firewall konfigurieren”,
By default is in there but if you are using e.g. 10.x.x.x, you have to enter the address of your OpenHab there.
Because it's also not mentioned in the Homematic manual, I was at the brink of throwing this out the window, shortly before I found it.

I'll probably not use Homematic in the long run and switch to Z-wave instead.

Meassuring energy consumption with OpenHab

I had another tutorial to follow here....and gave up on it.
It is written for an OLD version.
This /etc/openhab2/services/rrd4j.cfg  looks much better
Strategies {
 everyMinute : "0 * * * * ?"
   everyHour : "0 0 * * * ?"
    everyDay : "0 0 0 * * ?"

Items {
 // all items, all updates
 * : strategy = everyUpdate, everyMinute


 I did not get graphs to work until I added a
to each and every Chart in my sitemap. Then it suddenly worked.




Using RFIDler on Windows

I just borrowed an RFIDler and am trying to get it to work on Windows to read the content of some NFC cards.

Because this information was hard to pull together, here is what I found:

Firmware update on Windows

You can get mphidflash.exe from here:

You can get the latest firmware from here:
Currently it is 0203-beta (debug)

The command line simply is:
mphidflash-1.6-bin\binaries\mphidflash-1.6-win-32.exe -r -w RFIDler\RFIDler.X.production.hex

Reading cards

Positioning the cards seems to be hard.
I did not get it to work yet but it should be:

Open Putty
Open a serial connection with 115200bps 8n1 no flow control.
type enter to enter CLI mode.

should identify the type of card.

set tag  
sets the type of card

now provides information reat from the card.

source:  https://www.scip.ch/?labs.20151022


'roast only' on the Bonaverde - Aldo Parducci

Project history

  1. old posting: 'roast only' on the Bonaverde - Rodolfo Ruffatti
  2. current posting
  3. next posting: Coffee with bottled water

This time I tried
Bean Type:  Burbo
Grown by Aldo Parducci
of El Salvador

This is one of the larger bean packs I got from the first coffee delivery  for my Bonaverde Berlin roast+grind+brew coffee machine.

I used "roast only" in the alpha version of the "Coffee Concierge" Facebook Messenger Chat bot last night and ground+brew the coffee this morning.
Change to previous attempts: I used a water filter. (Water here has a PH of 7.57 but an extreme 12.2dH of hardness.)

Update: See Coffee with bottled water for later experiments with water that resulted in much better coffee.


 Again I used my Hario Skerton manual coffee grinder at the finest setting (dust).


not yet

filter coffee

Absolutelay GREAT!!!
Very balanced. Not sour at all. I can really taste distinct flavors.

Other changes 

I did add a new label "Coffee" to this blog. So you can see all postings related to it.

Also the "Coffee Concierge" Facebook Messenger Chat-Bot that controls the "Berlin" coffee machine has a new "abort machine" command. It however isn't recognized in all states and does not seem to abort a brewing cycle that has already started.



Fusion360 - you can NOT flip an axis in CAM

I just found out, that it is impossible in Fusion360 to have a single axis on your CNC be oriented differently.
All options to flip the direction of one axis in a CAM setup, also flip one of the others.

Looks like this will also never be fixed.

See: Fusion360 CAM support forum.