Sweet dreams are made of cheese

New babies started arrivning at the farm on Febuary 23rd. Let us take a moment to indulge in their cuteness:

Goat kids means cheese season is soon upon us. We will start weaning the oldest ones in the middle of April, and then we will be milking the goats twice a day until December.

A few of the babies are for sale, since our flock will have reached the size we want it to be (45 milkers) per next season.

Thanks for our first season!

Looking back on 2018, we can truly say it was the year it all began..

The first kids were born on the farm, 27 of them.

We finished building our dairy, we began milking our goats and then making and selling our very own cheese.

We participated in about 10 REKO-rings, several markets and events, and had lots of visitors who came to the farm, interested in seeing our newly started goat-business.

We continued improving the farm buildings by creating a storage place for our cheese.

We had help from friends, neighbors and several awesome WWOOFers.

Sweden experienced maybe the worst summer (for farmers) ever in modern age, with a drought  that lasted for over 3 months and temperatures over 30 degrees most days. We survived that!

We sold a few of our male goat kids and slaughtered 8 of them here on the farm. It was not a pleasant thing to do, we were sad to have to let them go, but take comfort in knowing the had a great life here with us.

We expanded our flock of chickens, from just a few to now having over 20 hens.

We were featured in local magazines, websites, and even got to be live on the local radio station! (see Media & press if you want to have a look or listen)

By the end of the year, we had met and even exceeded our sales goals for 2018.

All in all, it has been a year filled with joy as well as hard work. We are looking forward to 2019 and what we hope it will entail: ca 50-60 goat kids, milking around 30-35 goats, making and selling almost twice as much cheese, expanding our storage, and many other things!

We built a dairy!

For quite a while we weren’t sure if we should try and make our goat-and-cheese-farm dream come true by building a dairy on location or if we should try to rent a space in a commercial kitchen of some sort. The opportunity arose when Claire’s stepfather decided to bring a container with building materials from China for the house project he is working on, and let us have the container in return for storing the stuff in it on our farm for some time. We then decided that we should convert the 20 foot container to our very own farm dairy!

The container in place in front of one of our barns:

We poured concrete on the floor and made a drain:

Then we cut out holes for windows and doors, put up walls and a ceiling:

We poured more fine concrete as a final layer and had some “help” decorating:


Then we put up ceramic tiles on the walls, painted the ceiling:

In between there was a lot of work on things such as painting the floor with epoxi, connecting water and sewage, installing ventilation, and of course, putting a roof with a tilt on top of the container:


Finally it was time to move in all the equipment. This is Nils using our 300 l Rademaker cheese-making vat for the first time!

Claire in front of the cheese vat wearing signature hat and apron with our logo:

The whole project took us about 6 months from start to finish, while working with our day-jobs as well as taking care of the goats, etc. Did I mention we also delivered 27 goat babies..?

All in all, building our farm dairy was a really cool project which we are super proud of, and plan to put to good use as well as develop and expand during the years to come.

What’s cookin’?

We havn’t posted for a while – the thing is, that when you have a lot of projects going on, there is little time left for bloggning..!

Our main priority now is to find a decent cheese vat. We are rebuildning a part of the barn in order to make a milking facility for the goats, but it is time to get things going when it comes to the actual cheese making. To be continued… Until then, here are some photos of when we attended a course with the french expert Michel Lepage, hosted by Eldrimner.

Happy students, say cheese!
Happy students, say cheese!
Michel Lepage breaking the coagulated milk into curds. A true artist!
Michel Lepage breaking the coagulated milk into curds. A true artist!
Soon-to-be cheese. Just a few months of storage left..
Soon-to-be cheese. Just a few months of storage left..

 

DIY yoghurt maker

Even if we only milk one of our goats for the moment (and she is a low producer that give approximately half of her milk to a very hungry kid when they are together in the pasture), the milk bottles is filling up the fridge faster than we can consume it. We’ve already quit buying milk for drinking, coffee and cooking, so the next product to make ourselves will be yoghurt.

The process is rather simple, take some milk, pasteurize it if you don’t trust your hygiene, add bacterias and keep the temperature at the optimal level for as long as it takes for the bacterias to consume all accessible lactose and lower the pH to uncomfortable levels.

You can do this in your oven, but the temperature control will be crude, which results in runny and uneven yoghurt. There are yoghurt machines, not that expensive, that controls the temperature very well, but they don’t know when to turn themselves off, so you still have to watch it, or set the timer out of your best guesses.

Since my Diy wireless pH-sensor gives me the two variables I need to control the process (temperature and pH), I figured that I only needed a heat source.  Then I found something even better at a second hand store; a portable 12V peltier cooler/heater from Waeco, made in the early 90’s, featuring such elegant solutions as switching between heat and cold by turning the electricity cord, thus switching polarity.

This makes the perfect completely automatic yoghurt maker, since it both keeps the heat at an even level, and when the right pH is achieved, cools the yoghurt down to fridge temperature. Just throw in some milk and culture in a jar (or a teapot) and leave.

The controller is very simple. Since the only functionality needed that the waeco box didn’t handle, was the ability to turn on and off and switch polarity remotely, I connected a L298b motor driver and a NRF24L radio to an Arduino nano. The L298b module is normally used to turn DC motors forward and backward, but that could be applied to the peltier element in the box to make it hot or cold as well. Unfortunately, the L298b was only capable of 4 amps in throughput, and the waeco transformer supplied more even though it was specified for 4, resulting in a very hot chip. The solution was to use 2 L298b in parallell. Power cables as well as signal cables to the arduino.

28977497902_81aa65f9e6_o.jpg

The chips were still hot, but with a cooling fan from a PC chassi, they are now cold and very cool. I connected the fan to the input side to let it consume some power and make it easier for the L298b. That means that the fan is always on, which might be unnecessary.

The Arduino code for the controller is also really simple. I used the mysensors.org sample code for relay and made two adjustments: increasing the numbers om relays to at least 3 (I actually enabled 6, as there might be need for using the second channel on the L298b in the future, but for this functionality, you only need 3) and enabling pwm on the pins that controls on/off. I haven’t used pwm for anything yet, but that will allow me to control the current from the L298b output (speed, heat etc.).

The logic is placed in the home automation system I have running on a Raspberry pi. It is currently Fhem, but any system with support for the Mysensors library will work. Fhem is a quite complex system with lot of forum material in german, but if you are comfortable with both German and Perl, there is no more powerful home automation system in my opinion.

The controller presents itself in Fhem when the gateway is in inclusion mode, and this is the fhem.cfg code that is generated (with som additions):

 

define MYSENSOR_10 MYSENSORS_DEVICE 10
attr MYSENSOR_10 IODev gateway
attr MYSENSOR_10 alias Youghurt maker
attr MYSENSOR_10 mapReading_switch1 1 switch
attr MYSENSOR_10 mapReading_switch2 2 switch
attr MYSENSOR_10 mapReading_switch3 3 switch
attr MYSENSOR_10 mapReading_switch4 4 switch
attr MYSENSOR_10 mapReading_switch5 5 switch
attr MYSENSOR_10 mapReading_switch6 6 switch
attr MYSENSOR_10 mode repeater
attr MYSENSOR_10 room Dashboard,Mysensors
attr MYSENSOR_10 setReading_switch1 on,off
attr MYSENSOR_10 setReading_switch2 on,off
attr MYSENSOR_10 setReading_switch3 on,off
attr MYSENSOR_10 setReading_switch4 on,off
attr MYSENSOR_10 setReading_switch5 on,off
attr MYSENSOR_10 setReading_switch6 on,off
attr MYSENSOR_10 version 2.0.0

We can se that all 6 relays shows up, but I have only found use for three.

The logic doesn’t show up by itself so here I had to do som actual brainwork.

I found some excellent thruth tables here and got the following pin/switch setup:

Switch1/ENA: Main power 1=on, 0=off

Switch2=IN1

Switch3=IN2

Positive direction / heat: switch1 = 1, switch2 = 1, switch3 = 0

Negative direction / cold: switch1  = 1, switch2 = 0, switch3 = 1

Power off: switch1 = 0

 

The yogurt culture I am using prefers a temperature of 43 C and I will let it work until it has reached a pH of 4.20. I’ve hardcoded those levels in my config file for now, but an improvement will be to create a device that changes these values.

I want the machine to:

  • Rise and hold the temperature on 43 C.
  • Do that until pH has dropped to 4.20
  • Then cool it down as much as possible

That is achieved with the following code in fhem.cfg:


define phNotify notify MYSENSOR_118:temperature.* {if (ReadingsVal("MYSENSOR_118", "temperature", 0) > 43 ) { fhem("set MYSENSOR_10 switch1 off") } elsif(ReadingsVal("MYSENSOR_118", "temperature1", 0) > 4.25) {fhem("set MYSENSOR_10 switch1 on;; set MYSENSOR_10 switch2 on;; set MYSENSOR_10 switch3 off")} elsif(ReadingsVal("MYSENSOR_118", "temperature1", 0) < 4.25) {fhem("set MYSENSOR_10 switch1 on;; set MYSENSOR_10 switch2 off;; set MYSENSOR_10 switch3 on")}}

Worth mentioning is that the pH-sensor is called MYSENSOR_118 and its temperature sensor reports as temperature, while its pH-sensor reports as temperature1.

So this is the result. The red line is temperature, starting at fridge temperature at 6C and rising steadily to 43C where it plans out. Meanwhile the green bars representing the pH goes from 6.5 to 4.4 (at the time of the screenshot).

Obviously, the Waeco box isn’t made for heating, rather than keeping a temperature. The slow rise of about 8-9 degrees/hour making it 5 hour until optimal temperature is reached, is not acceptable. Heating the milk before putting it in the box is one easy solution, another is to never cool it down and let it go directly from the udder to the box.

 

Diy wireless pH-meter

In cheese-making, the key to a tasty, and reproducable, cheese, is keeping track of the  exact pH and the temperature in the active culture. You can do this with manual tools, such as a kitchen thermometer and pH-strips, but the measurements will be crude, and depend on your constant presence. That leading to inconsistencies between batches,  and difficulties in tracking errors in the process.

Michel Lepage is cutting the curd. Photo taken at the craft cheese-making course we took at Eldrimner in 2014.
A digital pH-meter is expensive. You can find some from €100, but you wont get built-in temperature correction for less than €250, and wireless goes beyond €350. For continous readings and  the possibility to recalibrate your sensor yourself, instead of sending it to the manufacturer,  add a lot more… I havn’t yet found a device capable of tweeting its readings 😉

My diy pH-sensor is not exactly cheap either. It ticks in at about €150 in material costs. I’ve seen people look pensive when they see the casing, and subconsiously push it closer to the recycling, so a slightly pricier casing than the pet bottle might be an investment. Otherwise, the bill of materials looks like:

Sensor

  • Atlas pH meter kit $149 (EZO version)
  • Arduino mini pro 3.3v $1.90
  • NRF24L01 radio $1
  • DS18B20 waterproof temp sensor $1.63
  • Battery holder $3
  • 2xAA batteries
  • Cables

With todays exchange rates, it translates to around €150.
If you’re setting up a new sensor network, you need a radio gateway and a computer to run the controller software on too

  • Arduino nano $6
  • NRF24L01 radio $1
  • Cables
  • Old computer or raspberry pi $25-$50

      You can order everything from ebay or aliexpress through the Mysensors store, but the items listed there may not always be availible in singel packages. Anyway, you will need more of those radios.

      Shipping is usually free from China (who is paying that?), but the pH-kit comes from the US, so add a few euros for shipping and customs.

      Features:

      • Measures pH-level in fluids and semi-solid compounds.
      • Calculates the correct pH from the latest temperature reading.
      • Measures temperature
      • 30 seconds between samples.
      • Continous measuring, just leave the probe in the milk and watch the readings.
      • Wireless transfer of data to the raspberry pi based controller unit
      • Presents the readings as a datastream or in nice graphs in a web interface. Use your phone or tablet to monitor the process from anywhere.

          Prerequisites:

          Tools

          • FTDI USB programmer, to program the arduino  mini pro and perform calibration. If you use arduino nano instead, you can skip this, but the nano is more expensive and power consuming.
          • Soldering iron, lead, soldering paste.
          • Computer with arduino ide or codebender running.
          • Pliers, knives, screwdrivers and that kind of stuff.

          Skills

          • Basic soldering. The only soldering done in my prototype is on the on/off switch. For a sturdy and reliable device to use in a kitchen environment, I recommend soldering the connections rather than using Dupont cables.
          • Basic programming. You can clone my code from codebender and hope it will work out of the box, but since things changed quickly on the internets of things, you will probably need to change some code to adapt to new version etc. So some understanding of coding will be helpful.
          • Arduino/MCU experiences. I wouldn’t recommend to make this your first microcontroller or Mysensors project. Start out with a simple blinking light and then a temperature sensor to make sure you get the IDE and Mysensors API.
          • Raspberry pi/Linux experiences. You could use a Windows computer as controller and user interface server, but if you’re up to arduino hacking, you might as well use an embedded device right away.