I tested fenugreek gum again.
The last time was probably an overdose. This time I adjusted the amount of fenugreek gum and detergent.
・ Fenugreek gum 12.5g
・ Water 3,500ml
・ Detergent (Cucute) 190 grams
The ph was stable at 7.3, so I haven't adjusted it.
18 ° C / humidity 94%.
I was able to stably create a bubble with a size larger than the previous time. You may want to reduce the amount of fenugreek a little more.
By adjusting the amount of fenugreek, the problematic odor was improved. However, it still has a unique spicy odor.
You should avoid blowing bubbles on someone's clothes or hair.
I'm surprised that there was still such an unknown natural polymer ... Bubble is really deep.
[Added in June 2021] When I used Dawn instead of Cucute, the odor was significantly reduced and almost unnoticeable.