We have been enjoying the great quantity of milk on our little off-grid homestead since the addition of Buttercup, our new Jersey cow. Now I allow the children to drink fresh whole milk whenever their hearts desire (almost) and we no longer purchase butter, cheese, or any other dairy products. We’re buying less store-bought food for the dogs and cat because they get milk every day as well.
With the extra milk we’ve been making lots of butter, cottage cheese, ricotta cheese, ice cream, kefir, ranch dressing, whipped cream, and buttermilk muffins and pancakes. When I scoop off the cream I like to make cottage cheese or ricotta with the remaining skim milk. But making cottage cheese (the quick way with vinegar) means using the gas stove for at least 20 minutes on high to bring a large pot of milk to the right temp.
It bothered me that we have loads of free energy around us every day and I’m “wasting” our propane on food we’re making ourselves to save money. How does that work? Thanks to the internet I found a really simple idea about harnessing the sun’s energy and tried it.
Can you imagine cooking with an accordion windshield shade? When I first came across this idea last year I had gone to Goodwill and found a shade and small grill rack to make this particular solar oven, but I hadn’t had time to try it. Now I fastened the shade’s sides together with clothespins to make a cone shape. The instructions say to sew velcro on the edges to secure it but I wanted to try it first before investing much in it.
I stuck the cone-shaped windshield shade on the five gallon bucket and placed a metal grill rack on it (a square cake rack would do). This secured it to the top of the bucket, making a sturdy place for my pot of milk. It also allowed the sun’s rays to shine under the pot and reflect all around it.
The instructions say to use a plastic baking bag around the pot to create a greenhouse effect. In order to bring the pot to a high heat and keep the heat around the pot, a baking bag or other plastic or glass enclosure would make it a lot more efficient. But I wanted to monitor the temperature of the milk and didn’t want it to get too hot anyway, so I decided to skip the bag.
I could have placed my gallon jar right on the metal rack, but sunlight kills some vitamins, including B vitamins in the milk. I usually make cottage cheese in a large stainless steel pot (Lifetime cookware), but in this situation the shiny exterior would deflect the sun’s rays away from the pot. I could have used a black cozy around the pot or painted my jar black. But since I didn’t need a really high heat for cottage cheese the simplest thing seemed to be to place my jar inside something black.
We have two granite buckets for milking the goats, and it worked perfectly to place the jar inside one bucket and use the other one in an inverted position as the lid. I made sure the jar lid was loose to allow air to escape while heating. I didn’t want an explosion! Once everything was assembled I propped the sides open with a stick and aimed the cone toward the sun.
My first try took nearly six hours to bring the milk to the desired temperature because every time I checked on it the wind had blown the windshield shade around and messed things up. After two hours I got the stiffer and sturdier shade out of our Suburban and tried again. It was also taller and worked much better. Now the Suburban has inherited the small flimsy shade.
Once I reassembled everything with the new shade we began to make progress. A few hours later the milk had reached around 125° F and was ready to make cottage cheese! I was so tickled that it had actually worked!
I called Silver Oak and told him that I had just made cottage cheese without using any fuel, and he was quite pleased with his wife. :) The next several days I made a batch every day. It usually took between three and four hours to reach the desired temperature, and I turned it more directly toward the sun about twice during that time.
Now that I’ve successfully used the sun in this simple way for making cottage cheese, I hope to learn more and reach higher temperatures. This method is valuable in that the materials used would be quite easy to transport or include in a bug-out bag in an emergency. There is so much to learn, and lots of ideas out there being used around the world. Here is one place to start. Next I want to try using an old tv dish to make a parabolic solar cooker.
Last week the weather changed a bit and it was very windy for several days, making it difficult to set up the windshield shade cooker. So I mostly made ricotta cheese which requires no heat, and was able to save cooking fuel that way. The adventure continues as we work toward our goal of living sustainably.