I'm apologies for being a truant on my own blog lately. I'm working toward scheduling more time to work on blog posts but I'm not there yet. I've discovered over the last couple of years that one doesn't own a business - the business owns you!

Eight years ago, I taught a class on making glue for a living history group and when I was done, I posted my class notes on the subject on my living history oriented website, rocks4brains.com/stuff.html. The glue handout is at rocks4brains.com/glue.pdf. In that handout, I described making cheese glue, which is a Medieval variant of casein-based glues like pre-WWII Elmer's wood glue. Casein glues are made by exposing milk-product caseins, which is what's in curd, to an alkaline solution to unkink and unwind the protein micelles and then introducing Na+2 or Ca+2 to rebind those proteins to make glue.

I got an email this morning from someone thinking to replace the pickling lime in my cheese glue recipes with borax. Here's the email and my reply:

I am writing after visiting your website, though it seems like there has been no activity in it for a while.


I should really write a more modern website and update stuff but I'm lazy...

Anyways, trying my luck: i am trying to make my own glue - casein glue actually. I wish to use borax as the alkaly agent, i also wish to avoid lime. any other suggestions? <

Dear ---, looking at the chemistry, I don't think that borax will work well. It's a pH buffer and water softener. 

In solution, it's going to form sodium cations (+2) and a borate complex (-2). Borax solution is a second-rate water softener (i.e. it REDUCES alkalinity) and it is more commonly used at labs to buffer enzyme solutions to maintain near-neutral weak alkalinity. Unlike lime or lye, it's not a caustic. Also, the sodium cation released from borax is not as effective as calcium in rebinding cassein proteins. So borax gets you a wimpy anion complex that actually decreases alkalinity and buffers solutions to near-neutral pH; plus, Na+2 is less effective compared to Ca. That makes it a far worse choice than baking soda. If you want to avoid the lime compounds and still get a usable cheese glue, use baking soda. 

I don't use baking soda to make cheese glue so I don't have my own recipe for it. If I were doing this, I think the first thing I'd try would be the Cennini-based recipe but with 2 parts skim mozzarella to three parts baking soda and then experiment from there to obtain the optimal ratio of cheese to baking soda. 

Hope this helps, Cate

Borax - it's a buffer and reduces alkalinity, which is the opposite of what you want to make casein glue. If you want deep details on the chemistry, check out my glue handout whose pdf URL I have already provided.