Kid Safe Glue From Milk





Introduction: Kid Safe Glue From Milk

About: I have been working with wood since I could stumble into the shop with my dad. About a year ago I moved into a house with no space for a full shop so I decided to take up all hand tool wood working. That sta...

Casein glue is glue made from the protein in milk. It is a very simple and quick glue to make and because it comes from milk it is non-toxic, safe and fun for kids in projects and woodworking.

Skim Milk -

Vinegar -

Baking soda -


Heat source

Mason jar

Step 1: Separate the Casein From the Whey

To begin, start by warming up two cups of milk in a saucepan. The milk should be brought to a temperature that is warm to the touch, but not hot enough to hurt your hand. Next, add 2 ½ to 3 tablespoons of vinegar and stir the mix. Look for the whey to turn almost clear and separate into large chunks of casein and liquid whey. This separation will happen very quickly. If you have been stirring for a while and this does not happened then just add a little more vinegar.

Step 2: Strain and Deacidify

After the whey and casein have separated, you can strain them through a towel or cheesecloth. Another way is to clump together the casein in the mix and just pull it out of the saucepan and dump off the whey. Next, we need to add 1 tablespoon of baking soda. This will react with the vinegar to make the pH less acidic.

Step 3: Add Water and Storage

In this step, add 3 to 4 tablespoons of water and warm it on the stove. The baking soda will create bubbles and you need to watch the pot carefully so it doesn't suds up. Continuing mixing the lump of casein until it becomes completely liquid in the water. At this point it is done and ready for use. You can use it straight out of the saucepan or store it in a jar for later use. If kept in the fridge it should last for several weeks, but if kept on the shelf you might want to use it that day as it will start to smell if it sits around too long.

Step 4: Use

Casein glue can be used for crafts or anywhere where paper craft glue would be usually used. Some use it for woodworking or other larger crafts. Since it is made from milk, it is completely safe to use in food-related crafts and other places where kids might be tempted to drink the glue.



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    22 Discussions

    Wow that it is really cool. First time i heard for this . Hope it works will fallow all steps

    I've tried spraying skim milk to fix charcoal and graphite drawings. I like the idea because skim milk does not contain potentially harmful solvents present in most commercial fixatives. The drawback is that it dries very slowly and one can easily soak and ruin a drawing. Perhaps if I watered down this milk glue to a suitable viscosity I might get the best of both worlds. What do you think?


    3 months ago

    When is the glue test going to occur and how do we make sure we don't miss it?

    1 reply

    I am hoping to do it in a week or two. I am just waiting on gluing up the final blocks and the rig to be shipped to me.

    I use milk straight out of the bottle (or even made from powder) to stick labels on jam jars. They stick as long as you want them to and wash right off when the jar is empty.

    1 reply

    There's a lot more than that! If you don't add your baking soda, the casein clumps can be sieved through a sock and dried to make something called Galalith (Erinoid in the United Kingdom), a plastic that can be sculpted (but not moulded) and that is fairly resistant to heat (goes to dust beyond 700ºC, never burns). Now, if you mix (fast but thoroughly) some 2-3 spoons of baking soda to the clumps, stick it between 2 oven dishes (add lest on top and half a centimetre between the 2 dishes), put it in the oven at 60-70ºC for an hour, you get a tile that is basically a hydrofuge aerogel, with the weight mostly coming from the CO2 bubbles. However, when exposed to a blow torch, it is an active flame repellant... Amazing, isn't it? I think it's probably the secret behind "Starlite"...

    1 reply

    So true. it is also the original basis for water-based paint. just add pigment and paint with it. Also can be used as fabric starch, or theater sizing. a very useful substance.


    Question 3 months ago

    I notice that you list only skim milk. Can this be made with whole milk as well?

    1 more answer

    yes, but you have to skim off the fat first. skim just takes care of that first.

    In Step 3, you mention that "if kept on the shelf you might want to use it that day as it will start to smell if it sits around too long."

    After the glue dries, does it still continue to "spoil?" I'm thinking if it is used in woodworking projects, will the project eventually smell bad?


    1 more answer

    3 months ago

    This is great; I have been looking for casein wood glue for long time as it is strong, resist humidity and, can cure at low temperatures. I hope this glue can replace the long gone casein industrial glue, so common 40 years ago.

    1 reply

    I am looking forward to trsting it in the upcoming glue test. it will be cool to see if it stands up to what people say it can do.

    An excellent instructable. I always liked casein based glues, especially the powder based ones that you mix with water. However, although casein is safe (see please don't equate 'natural' and 'safe' - after all, some of the most poisonous substances are purely natural, like ricin. The only way to find out if something is safe is to test it.

    1 reply


    very true, but in this case, it is safe. you would have to eat a ton of it before you run into problems. constipation would be the big first one.

    Real good instructable. Well explained and great details.

    Just wanted to add casein ist completely safe but "because it is made from milk" is not the best reasoning. You can extract pretty dangerous substances from food ingediences (poison/acid from almonds, drug/poison from nutmeg), so just because something is made from safe substances does not mean the result is too. (works the other way too)

    1 reply

    very true, but in this case, it is safe. you would have to eat a ton of it before you run into problems. constipation would be the big first one.