Here’s a follow up to my previous post, with me now making a batch of casein glue from the Kalona brand milk I bought. It looks like it will work just fine.
As a reminder, this milk is different than the sort normally sold at a grocery store here in the US. It’s non-homogenized, low heat pasteurized, and about the closest type to raw milk you can buy. Here’s how I made the casein glue from it:
First I poured 8 ounces of the milk at room temperature into a small pot, and heat it to about 150 degrees, making sure it doesn’t get over 190. I stir in two tablespoons of white vinegar. In a few seconds it congeals into a ball of casein.
I crumble the casein into a fine mesh strainer, and wash it under the tap for a few seconds until the water is clear to remove all the whey and any byproducts that may be in the milk.
Next, I dilute a 1/2 teaspoon of borax in 2 tablespoons of distilled water. This alkali will change the casein into a glue. I put the casein in a small jar, and stir in the borax liquid.
I stir the contents every 20 minutes or so, and after about four hours it turns into a thick gel. It’s still a little lumpy at this point, so I would want to let it sit for a few more hours before using it for anything. I added a drop of thymol as a preservative.
So, this brand of milk works well as a source for making casein glue as a binder for paint or gesso. The biggest drawback is that it’s pricey. It’s twice as expensive as the last jug of raw milk I bought, and three times the price of regular commercial milk. It would be better if I could get it in a smaller size, since this is way more milk than I need. Unfortunately, it’s only available in 1/2 gallon. I can also use it for food, of course. It tastes okay, a little more buttery than regular milk. I could make cheese from it, but would want to use something other than vinegar, perhaps lime juice.
Well, the lime juice worked. I substituted it for the vinegar, using half a lemon, and the casein separated from the whey easily. It took a few extra seconds, and more stirring, but the results were the same. I’m not certain, but the casein felt not quite as firm this time, however. I saved the whey and lime juice liquid, and added it to my pasta sauce for tonight’s dinner. I mixed some oregano into the casein (a.k.a. cheese) and crumbled it on top of the spaghetti. Tasted good.