I managed to publish my DIY reverse osmosis filtration system with timer functionality and automatized flushing features on GitHub. It is an innovative approach to automating a reverse osmosis water filtration system. It utilizes a Raspberry Pi Pico, programmed with MicroPython to control four valves the are coordinated for a filtration process. Its main features are:

  • Automatic flushing of the osmosis membrane every few hours to prevent germ development in the filters.
  • Automatic disposal of the first filtered water (which contains more particles due to the lowered pressure in the osmosis membrane during idle time).
  • Setting a fixed time interval for water filtration to yield a specific amount of water, which can be stored via a long button press.

The project is developed in Python and is shared under the GPL-3.0 license. For an in-depth understanding and access to the script as well as a list of all hardware parts, you can visit my GitHub repository.

January 21, 2024 My Life

Bremen just feels like a winter wonderland. After snow on Sunday we got a bit of new snow yesterday and quite some New snow today 🙂 . With temperatures around -6°C it is nice and cold outside. Good sledge conditions. It is only somewhat difficult to find the right hills in flat city. But even this is feasible 😉 .

January 5, 2016 My Life

I tried to program a very simple game (in Python) using the wonderful Monome interface (along with libmonome as software library).

My daughter really seems to enjoy it. Hopefully there are more games to come 😉 .

December 3, 2014 Development, Family, Fun, Linux, My Life

Everyone loves chocolate… and so do I 🙂 ! As I love to understand the various health aspects of food that we eat, I was curious in making a healthy chocolate. Of course I am not the first person to discover this. Nevertheless, it took me some time to experiment and find the proper resources that helped me understand the process of making chocolate. So, I would like to share this information.

Here is the list of the ingredients for my personal chocolate recipe. To truly benefit from cacao, we need to make sure that our ingredients are raw ingredients if possible. As sweetener, I tend to use xylit as it has good sweetening properties and it has no negative effects on our body (it is even good for your teeth health!). Here are all ingredients you need:

  • 250g raw cacao butter (250g)
  • 6 tablespoons raw cacao powder (feel free to add more)
  • 8 tablespoons xylit (ground to be powder so that it can dissolve more easily)
  • Almond creme (2 tablespoons)
  • Spices: a tiny bit of (ground) salt, vanilla (very important!), cinnamon, chili powder

 

Crystallization properties of cacao butter

Have you ever tried to melt the chocolate and then to put it into the fridge? What was the result? When I tried it, I experienced crumbly and soft chocolate which melts to easily. The surface was not nice and shiny, but rather dull and unpleasant. This is due to the fact that cacao butter has different types of crystals with different melting properties.This is why one needs to temper chocolate. Wikipedia summarizes this nicely:

The final process is called tempering. Uncontrolled crystallization of cocoa butter typically results in crystals of varying size, some or all large enough to be clearly seen with the naked eye. This causes the surface of the chocolate to appear mottled and matte, and causes the chocolate to crumble rather than snap when broken. The uniform sheen and crisp bite of properly processed chocolate are the result of consistently small cocoa butter crystals produced by the tempering process.

The fats in cocoa butter can crystallize in six different forms (polymorphous crystallization). The primary purpose of tempering is to assure that only the best form is present. The six different crystal forms have different properties.

The different crystal types with their varying melting temperatures and properties are the following (also taken from Wikipedia):

Crystal Melting temp. Properties
I 17°C (63°F) Soft, crumbly, melts too easily
II 21°C (70 F) Soft, crumbly, melts too easily
III 26°C (79°F) Firm, poor snap, melts too easily
IV 28°C (82°F) Firm, good snap, melts too easily
V 34°C (93°F) Glossy, firm, best snap, melts near body temperature (37°C)
VI 36 °C (97 °F) Hard, takes weeks to form

This is why we will need the tempering process as described below.

Armed with this important secret of making chocolate, we can now start to actually make chocolate…

 

Step 1 – Make xylit powder

Use a coffee grinder or a small blender to grind the xylit. Xylit crystals will not dissolve easily in cacao butter, so grinding the will spread the sweet taste of xylit well in the chocolate.

 

Step 2 – Melt the cacao butter

The easiest way to do this is to but a bowl with cacao butter into a bowl with warm water (it should not be to hot). Monitor the temperature (best with a infrared thermometer) until the cacao butter has reached approximately 43°C. This way we make sure that no ingredients of the cacao butter will be denatured by heat.

 

Step 3 – Blending ingredients together

Now it is time to blend all ingredients into a nice dark chocolate mass. I like to use a blender on a small speed level. Blending helps for building up many small crystal seeds. These little seeds will then later help to build up a fine cacao butter crystal structure.

 

Step 4 – Tempering

During blending, the chocolate mass will cool down. Let it cool down to about 28°C. Now we want to make sure that our chocolate contains as many type V crystals as possible. For this we will heat up the mixture up to 32°C and thus we will give more time to the type V crystals to form. You can heat up the chocolate mass again in a water bath. Make sure that you stay below 32°C while observing carefully the temperature. At any time, it is important to keep stirring in order to spread the heat evenly.

 

Step 5 – Mold the chocolate

It is now safe to pour the chocolate mass into any mold you like. Let it cool down at room temperature. After some time, be amazed about your home made healthy chocolate that has a nice, shiny texture and a firm snap 🙂 . Enjoy!!!

 

September 1, 2014 Food, My Life

These days, I received an email at noon from my wife showing me some pictures that proof how much my daughter loves green smoothies! Indeed, they seem to inspire her very much. Thanks to them, Lucie could start to discover her sense of art and painting 🙂 . How wonderful!

January 9, 2014 Family, Food, My Life

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