This Vietnamese recipe uses agar agar which is a great vegan alternative to gelatin. It really helps make the texture of this yogurt firmer. Most of the yogurt I had in Vietnam was liquidy, which seems to be the standard there, but I prefer the addition of optional agar agar for firmness.
American vs. Vietnamese Yogurt
Vietnamese yogurt is different from our familiar American variety due to the addition of condensed milk, which was more readily available than fresh milk. This added sweetness from the condensed milk complements the tangy flavor of the yogurt.
Similar to other yogurt recipes, Vietnamese yogurt relies on using live, active cultures. There are many different types of active cultures you can use, but you need at least one active culture: Streptococcus thermophilus, Lactobacillus bulgaricus, etc. These live active cultures in the yogurt are what help turn the milk into lactic acid and create that tangy flavor in the yogurt.
There are many options for yogurt machines out there and they all basically do the same task: to hold a certain temperature for a set amount of time for the active cultures to do their thing.
Knowing that, you can make yogurt in Instant Pots, or even in your oven. But often times yogurt makers / machines come with properly sized jars for snacking, a timer for cooking, and are pretty compact.
Live Active Cultures
Fresh, homemade Vietnamese yogurt can last for about two weeks in the fridge. Note that the tangy flavor does get stronger the longer it is in the fridge, so I prefer to eat the yogurt within one week. These are great for a nice light breakfast or snack in the middle of the day.
What does Vietnamese yogurt taste like?
Vietnamese yogurt has a sweet and tangy flavor from the fermented whole milk and condensed milk.
How long does homemade yogurt need to incubate?
This recipe has Vietnamese yogurt incubated for about eight to nine hours, but the time can increase in colder weather, or decrease in warmer weather.
What happens if you use too much yogurt starter?
I do not recommend adding more starter yogurt than necessary. If you use too much starter, this could change the consistency, bacteria growth, or fermentation period for your yogurt.
How do I make my homemade yogurt thicker?
I like to use agar agar in my recipe, suggested by my mom, to make sure it has a thicker consistency.