Easy yoghurt

[TZ-Someplace]

I never would have learned to cook if I had relied on TV (now YouTube) chefs. They seem to make everything overly complicated.

Here is easy yogurt

--Milk heated to 180-200F then insulated for 30-40 minutes in a 'cold' oven. This step promotes thickening, sterilization is irrelevant.
--Cool the pot to 100-110F (I use the kitchen sink filled with cold tap water) and inoculate with active yogurt, 1-cup (no more) per gallon.
--Pour through a wire strainer into containers (scorched milk leaves floaters).
--Incubate in oven for 5-12 hours. The oven (insulated box) was pre-warmed by the pot of hot milk.

The end.

If you use 1 to 1.5 gallons of milk and put it into 24-32 oz plastic containers saved from cottage cheese or yogurt they will fill or nearly fill an oven rack and maintain incubation temperature (place the rack high in the oven). The oven light is not needed for heat. Do not use new Tupperware-type plastic food containers or a strong plastic smell can leach into the product and ruin it. If you make a smaller batch you can put a large container/s of hot tap on the rack with them to help keep the temperature up on a cold day.

In my experience, high quality active Greek yogurt such as Oikos or Chibani sets up/gels thicker than cheaper brands (the two make slightly different results due to Chibani's extra bugs in the mix). All you need is the cup-ish size container that is common in stores to add to a gallon of milk (plain is preferred but flavored yogurt works too). After one batch you can just use yogurt from your last container for the next batch. I also make an inoculant container and freeze it after incubation. After several cycles of incubating with yogurt from the previous batch the product may get too tart, that is when I go to the freezer for the bit I saved from the first batch.

Trouble shooting:
Lower temperature incubation (95-100F) needs longer incubation time to set up.
Longer incubation time at middle-high temperatures can make the flavor more tart (but generally doesn't with new cultures).
Curdy/grainy yogurt on the bottom may result from higher temperature incubation (110-115F).

Tip: Stand there and constantly stir along the bottom with a pancaked turner after the milk gets warm-hot. Milk scorched on the bottom of a pot is not fun to remove. Heating to 180F takes about 15 minutes on high heat. It's not like the ladies on YouTube who stir occasionally while bringing their milk to a boil. Maybe their brand new stove tops and pots, and "only of the highest quality" organic Kobe milk have something to do with it.

I use common jug 2% or whole milk. Supposedly, adding powdered milk (more proteins to gel) will make it thicker, but I want cheap and easy.
I get some variability in thickness among batches, which may be due to the culture age, the amount of culture I use and/or the incubation temperature, but since I mix in flavorings before eating that doesn't matter much to me.

My only failure was due to inoculating the milk when it was too hot (at or above 120F). The resulting product was runny and smelled like grassy manure.
If your yogurt is runny from not reaching/maintaining 170-180F you just have ungelled yogurt. Setting up/gelling is dependent on the milk proteins being denatured, which starts happening at 170F. 180F held for 30 minutes supposedly results in nearly complete denaturation. So does five minutes at 200F but I have found that raising from 180F to 200F results in a lot of scorching even with constant stirring, so it is not worth doing for me. Plus I get a warm box from letting the 180F milk sit on the oven and have time to get out all the other stuff I need.