Temperature rule of thumb "if it's comfortable for you, then it's comfortable for the culture"
The culture should not be exposed to strong sunlight. However, ambient, indoor light or outdoor shade seems to be fine. The biggest culture I ver did was done in a kiddie pool that was housed in a tent.
Commercial iced tea (pre-mixed or powdered drink mix) works well as a culture medium. However, the powdered stuff often has dye that will give the cellulose some pretty "interesting" (gross) colors.
If you are using sucrose as the sugar, then the ideal seems to be about 1 cup per gallon of water.
When you harvest, you can kill the funky smell by soaking the sheet in a solution of baking soda. If you want to bleach it, you can boil it in a weak solution of sodium carbonate (washing soda).
If you want it to stay pliable forever, you can use cyclopentasiloxane or dimethicone (these are silicone oils that can be found in hair care stuff that makes hair soft and shiny)
And a write-up of a "tealess" recipe that can be used to make pale cellulose:
https://www.hive76.org/2011/11/24/microbial-cellulose-2-a2-sheets-worth/
And a write-up of my first effort:
https://www.hive76.org/2011/06/21/cellulose-some-and-you-win-some/
Honestly, it's hard to fail .. the Acetobacer Xylinum grow vigorously at "room temp" if given enough oxygen (flat try takes care of that), and they drive the culture to such a low pH that they kill almost all potential competitors.
If you read up on Coco Nata, there are some descriptions of how they use weak sodium carbonate to clarify the cellulose.
The 1 cup per gallon rule for batch processing came from a science project my son did in high school. Anything much over that tends to leave a lot of unreacted sucrose in the medium. Much below that, and you deplete the sucrose (and limit growth) before reaching full thickness.
Fed batch or continuous batch would be really interesting, but I have yet to try either.
Also, some strains are more productive than others. If someone manages to isolate a super-cellulose strain, I would be interested.
I think that the growth rates you quoted are a little on the low side, but great job showing how simple the process really is.
For keeping the scoby supple .. have you tried silicone oils? Hair polish is usually cyclopentasiloxane and dimethicone. They seem to penetrate the material well, and seem to last a long time without any noticeable drying.
I have tried it, by myself in my kitchen. Six batches with 4 l sweet tea. I have notes in my lab-book to prove it (se video). But in my experience growing it yourself in the kitchen is not the way to do it. Every time I tried it, it predictable started to mold (se video).
Sure I have tried to clean everything in my kitchen first with soap then with bleach. But let’s say every m³ of air in my kitchen has X mold spores. As you know, X is an astronomically large number that even if cleaning with bleach is so effective it reduce the number of spores to 0.1X / m³, there will be tons of mold spores contaminating the batch. In the other hand, it is not like everyone brewing kombucha has access to a lab with HEPA filters and UV-light and stuffs. I think it should be possible to make att home.
I have tried it, by myself in my kitchen. Six batches with 4 l sweet tea. I have notes in my lab-book to prove it (video 1). But in my experience growing it yourself in the kitchen is not the way to do it. Every time I tried it, it predictable started to mold (video 2).
I have tried it, by myself in my kitchen. Six batches with 4 l sweet tea.
Thank you all!
Btw for you how thinks about trying this. They are not kidding when they write to use tea bags. One mistake I did was using loose tea at first. So I know about the problem of small pieces of tea blade getting in the batch.