The other day, I found an article online about fenugreek being used as a thickener.
Fenugreek endosperm is mainly composed of galactomannan and is said to have excellent solubility and dispersibility compared to guar gum and locust bean gum. (The ratio of galactose to mannose in fenugreek gum is 1: 1, whereas that in guar gum is 1: 2 and that in locust bean gum is 1: 4. Decreased proportion of galactose makes it less soluble in water.)
A Japanese company extracted only the endosperm part from fenugreek seeds and sold it as a powder.
I was intrigued by this, so I got it online shopping, and tried it as a polymer for bubbles.
I tried it with the following recipe.
・ Fenugreek gum 17.7g
・ Water 3,500ml
・ Detergent (Cucute) 220 grams
(When I finished mixing these, the pH was 7.2-7.3, so I decided that no adjustment was necessary.)
Like guar gum, I made a slurry with isopropyl alcohol and dissolved it in water.
I did a quick test early the next morning. Temperature 19 ℃, humidity 84%. The solution is similar to guar gum, but very viscous.
Yellow solution like curry soup...
This solution seems to have been an overdose. The amount of fenugreek gum should be reduced.
Giant bubbles are short-lived. However, it makes me feel the possibility of creating a huge bubble. Bubbles of about 1 meter can be easily created.
There is a caveat!
Fenugreek seeds are a type of spice and are an ingredient in Indian curry. The smell of fenugreek gum powder is intense! (The manufacturer's product description says that there is almost no odor, but I don't think so.)
If you mix it indoors, you need to be prepared for your room to smell like an Asian spice shop.
Mixing detergent makes it a little better. However, both the bubble solution and the bubble itself have a slightly spicy smell of curry. I don't recommend trying this solution where there are children or others.
It has some odor drawbacks, but it was good enough to make me want to try again. I will continue my search.
[Added in June 2021] When I used Dawn instead of Cucute, the odor was significantly reduced and almost unnoticeable.