Milk substitute for home-made glue

Question

Home-brewers often use milk-based recipes — or literally just milk — to glue labels to bottles. Presumably it's the casein in the milk that allows this to work.

This kind of glue has the advantage that it's easy to make and use, and strong enough to stick reliably to bottles, but also doesn't leave residue when washed off with warm water.

Vegan gelatine substitutes are relatively easy to find, and agar would probably work for this, but what's a good substitute for the milk protein? Or alternatively, do you know of any commercial vegan glues that would have the desired properties?

I already make vegan beer, but it would be a shame to have to rely on animal products in the packaging!

Answer 1

The first thing that popped in mind was flour glue, which is cheap, easy to make and possibly strong enough for glueing on glass bottles. It might be worth a try.

However, I found a glue recipe suited for papier maché crafts, which seems ideal for your use case.

Recipe (excerpt from the WikiHow article aforementioned):

Ingredients

• 1 cup flour
• 1/3 cup sugar
• 1- 1 ½ cup water with 1 tsp white vinegar mixed in

Directions

1. Gather your ingredients. You will use flour, sugar, water and vinegar to make paper mache glue. You can adjust the recipe as needed to make more or less glue. The basic proportions are 3:1 for the flour:sugar mixture. Use one teaspoon of vinegar for every cup of flour you use.
   If you want a smoother paste, you can sift the flour before you make your paste.

2. Mix one cup flour with ⅓ cup sugar. In a small saucepan, mix the flour and sugar with a spoon or whisk until well-blended.

3. Add ¾ cup water and one teaspoon vinegar to the mixture. Blend the mix until it is very smooth and lump-free. It will have the consistency of a thick paste. When smooth, whisk in the rest of the water, ¼ cup to ¾ cup depending on how runny you want your paste, and mix thoroughly. Blend your ingredients until your glue is smooth and a little runny but not watery. Your paste should not be too thick or too drippy.

4. Cook over medium heat. Pour your mixture in your saucepan and turn on the heat. Stir the mixture constantly until the mixture begins to thicken. Once your mixture starts to boil, you can turn off the heat.

5. Let your glue cool before using it. When the mixture has cooled, use it for any craft projects including paper mache. Once you have finished, keep any unused glue in a tightly-sealed container in the refrigerator. This glue will keep for 2 to 4 weeks in the refrigerator.

6. Glue something! When cooled, you can use this glue to make paper mache, craft projects, and anything else. It's totally non-toxic, too. Make sure to dry thoroughly any of the crafts you make with this glue. If the project stays damp, it may grow moldy over time. Mold needs water to grow so as long as you pat your products dry or heat them over an oven, you will keep mold away.

This article offers three other recipes you could try (if we except the one based on dairy milk), but I think this one is the best to suit your needs.