These powdered cultures work fine.
I use powdered culture as well and then use the actual yogurt to start new batches. Even after more than six generations I didn’t notice any difference in the end result. Mind you I use individual jars of 200 ml thus limiting in a big way the change of contamination compared to making 1 litre batches and using a bit of them.
For powdered culture see:
chaoshi.detail.tmall.com/[...]

Yoghurt cultures are a combination of various bacteria that turn milk into yoghurt.
Nowadays we are usually used to the combination of streptococcus thermophilus and lactobacillus bulgaricus. This gives a rather mild only slightly acidic yoghurt.

If lactobacillus acidophilus is used then one tends to get a more acidic thus sour yoghurt.
Lactobacillus acidophilus is a very common bacteria that lives on your hands and in your mouth and in your guts. It is a very strong bacteria compared to the other two and can dominate them. So if you use yoghurt over and over again as a starter there is a real change that lactobacillus acidophilus takes over and you get more acidic yoghurt. Contamination of your culture can as well occur when your yoghurt to be comes in contact with the lactobacillus acidophilus living on you. (You can just spit into milk and make yoghurt that way). Avoid using old yoghurt as starter culture when this yoghurt has been contaminated for instance by a spoon that has been in your mouth.
As tiger mentioned above a higher level of hygiene can avoid this or using fresh starter culture with only streptococcus thermophilus and lactobacillus bulgaricus.

WeChat has a build in translator as well. Easy for translating screenshots on your phone and translating any text you can make a photo off.

@bolang
You can't sneak in and out with all the camera's that are monitoring things. But I reside outside the second ring road. You cannot even register a motorcycle when your address is within the second ring road. Anyway I sold mine, driving around Kunming was becoming too dangerous. Motorbikes are the lowest in the picking order, mainly driven by farmers and the attitude against them here in KM is not nice (Unless you have a big show-off bike).

Martin4privat in an other thread wants to buy a small business in Kunming. See:
www.gokunming.com/[...]
This means a student visa is out of the question.
You will need a proper working visa and those depend on registered capital of your company and things like that.