I've been attempting to produce home-made yogurt.

The tl;dr: Pre-heating the milk to boiling or near boiling, allowing it to cool, adding the cultures, incubating 24 hours, chilling for 12, and not stirring until after chilling results in the firmest and most consistent outcome.

Update: 12 hours incubation seems to yield the same result for a total of 24 hours, or at least it does to my sense of taste. Also, heating it on a stove top to near boiling for a total cook time of 15 minutes is just as effective as pressure cooking it for ten minutes and the pan is easier to clean than the pressure cooker.

• pressure cook 1/2 gallon of whole milk for 10 minutes on low

• allow to cool without removing the lid (reduces film/skin)

• remove the film

• whisk in cultures

• split between the containers to be used

• incubate 24 hours

• chill for 12 hours

• stir in frozen fruits if desired, otherwise eat at will

I don't know where I ultimately found this piece of wisdom, but it bears emphasis: DO NOT STIR THE YOGURT AGAIN ONCE THE CULTURES HAVE BEEN STIRRED IN. Stir it when serving.

I use two large containers, in theory I could split it amonmg the tiny jars and use those, but I imagine that it would have to sit for a while between mixing and splitting and I didn't want to have to track another variable.

The cultures claim to be good for 1.5 quarts, but incubating for 24 hours more than makes up for the volume difference. The outcome is smooth and tasty. I could probably incubate for only 12 hours with the pre-heated milk, but I really want that sugar to be gone because I don't know how to measure the sugar content of something at home. I mean, aside from knowing how much sugar is added. Theoretically the cultures are consuming it all, but I don't know how to measure it to be sure it's completely gone.

No straining is needed. I didn't even know straining was a thing.

It's \$2 for a half gallon of whole milk. It's \$9 for a 10-pack of starter cultures. I need to measure the wattage drawn by the device that keeps it heated to figure out how much power it uses.

But still, approximately \$3 for a half gallon of yogurt versus \$8 if purchased from the store (bulk price there, \$12 for single-serve multi-packs, \$15 for the cleaner Greek yogurts!). No fillers, no piles of plastic and foil to recycle. It's very appealing. And it gets a little cheaper if I start re-using some previous batches to start the next batches.

The only issue is that it was somewhat thin -- a little too liquidy.

I used a full half-gallon of whole milk and a packet that claimed to be good for 1.5 quarts of whole milk. So it's not too big of a surprise it wasn't entirely set. I was hoping that keeping it at temperature longer would make up for the difference.

The instructions that came with the cultures said to keep it heated for 8 hours. I kept it heated for 24 hours and then let it chill for 12. The result was creamy and smooth with no separation and the flavor was good. It's just that I could pour it or drink it instead of needing a spoon to eat it.

A new batch, this time to keep it at temperature for 36 hours and then let it chill for 12. It was really close to the right consistency at 24, so I'm hoping this does the trick. If this fails, I can still try one more thing: keeping it heated to near boiling for 20-30 minutes before bringing it down to temperature and adding the cultures.

When the batch completed the 36 hours, I moved half of it to the fridge to cool. 12 hours later, the batch in the fridge is still not very firm. I moved the other half of the batch to the fridge to see how that one does. Maybe I will need to reduce the liquid (evaporation or near-boil or actually boiling it) before bringing it to the temperature required for the cultures.

It seems I made a tragic error in stirring the yogurt to see how well it had thickened after it was done incubating. My 36 hour batch featured two one-quart containers. One container I stirred to see how thick it was after 36 hours of incubation. The container I did not stir was much thicker than the first after the 12 hour cooling period.

36-hour incubation, no stirring.

I didn't try the second quart of the second batch until after starting the third batch, so unfortunately there's another variable changed with this batch, I pressure cooked it on low for 10 minutes before cooling it down to incubation temperature and adding the cultures. To make matters worse, the second quart of the second batch was moved to the fridge after 48 hours of incubation! So was the thickness due to not stirring or the increased time?

No pre-cooking, no stirring, it came out thicker, but was still drinkable after stirring it (just before consuming it). 24 hours of culture, 12 hours of chilling. It was fairly tart and not as richly flavored.

Pre-cooked, 24 hours of incubation, 12 hours of chilling. Nearly perfect. The flavor was good, not too tart. There was some clear liquid in the center of the second container. So the one that was undisturbed longer. But otherwise it was one large block of yogurt in both containers.

Input variables:

• pre-heating/pre-heating time

• incubation time

• cooldown time

• stirring before cooling

Output variables:

• thickness

• tartness

• richness

• longer incubation may produce a richer taste

• stirring it before chilling it may produce a runnier yogurt

• every case where it was stirred before chilling failed to solidify

• chilling it longer may produce a more tart yogurt

• does not seem to hold for the pre-heated batches

I suspect that stirring before cooling was the biggest problem in my initial approach, but it could be the longer incubation time. Or it could be that it's winter and despite the heating elements keeping the unit at 99F, the air being 60 degrees Fahrenheit could be preventing it from keeping it high enough? I doubt that's the problem, because the flavor of the yogurt is great. Though it was even better with the longer incubation period.

Tags: index, journal

created: 2026-01-01

(re)generated: 2026-07-17