Making yogurt

Yes — and I think your revised memory actually makes the project much more interesting and simpler. What you remember sounds very much like the traditional household method: heat the milk, cool it to roughly the right temperature by experience, add yesterday’s yogurt, cover it, leave it overnight, and refrigerate it in the morning.

And since you have several gallons of milk right now, I’d experiment before buying an expensive yogurt maker or exotic starter.

I would approach this as a little yogurt experiment

There are really three decisions:

1. What milk?

2. What starter?

3. How do you incubate it?

You already have #1 and #2 available.

For your first batch, I’d actually use a good plain store-bought yogurt that says “live and active cultures.” Store-bought yogurt can absolutely be used as a starter.

Then we can see what your particular milk + starter does.

I wouldn’t buy the Bulgarian starter yet

Not yet.

There are legitimate heirloom Bulgarian and Greek cultures available, and they are designed to be perpetuated from batch to batch. For example, Bulgarian and Greek cultures sold as heirloom thermophilic cultures are intended to be reused rather than treated as one-time packets.

But buying one now would introduce another variable.

I’d first make:

Batch #1: your store-bought yogurt starter

↓

Batch #2: yogurt from Batch #1

↓

Batch #3: yogurt from Batch #2

Then we can taste and evaluate it.

If you love the process but want a particular old-fashioned Greek/Bulgarian flavor, then I’d experiment with heirloom cultures.

And I wouldn’t necessarily buy a yogurt maker either

This is where your memory of the 90-year-old woman is useful.

There are two fundamentally different approaches:

Traditional

Heat → cool → inoculate → cover → leave overnight

That’s probably the method you’re remembering.

Controlled

Heat → cool → inoculate → hold around 105–112°F for ~6–12 hours → refrigerate

That’s the modern controlled approach. Thermophilic Greek/Bulgarian cultures generally like around 110°F, and commercial yogurt makers are designed to maintain that temperature.

The controlled method is much more repeatable.

But repeatability isn’t necessarily the point of your experiment.

I’d actually like to see whether you can make excellent yogurt using the old method.

Your first batch could be very simple

I’d start with one gallon, not two.

You don’t want to risk two gallons while you’re learning.

Equipment

You really only need:

• stainless-steel pot

• clean glass container(s)

• spoon

• thermometer

• plain yogurt with live cultures

• milk

You can use ordinary glass jars. You don’t need special yogurt containers.

For example, 16-oz glass jars are a convenient size, although I’d probably use four 1-quart-ish glass containers for a gallon rather than dozens of tiny jars.

Actually, ordinary Pyrex/Mason-style glass jars are perfectly reasonable. I wouldn’t spend $50–100 on special yogurt jars yet.

Here’s the experiment I’d do with you

Rather than blindly following somebody else’s recipe, I’d make your first batch almost exactly like the woman you remember.

1. Heat the gallon of whole milk

I’d take it to approximately 180°F.

Traditional yogurt instructions commonly heat milk around 180°F and then cool it before adding the culture. The heating improves the eventual texture, not merely the safety of the milk.

2. Cool it

This is where your woman’s finger test becomes interesting.

Instead of trusting the finger alone, we’ll use a thermometer the first few times.

Aim for approximately:

110–115°F

That’s warm enough for the culture but not hot enough to damage it.

3. Add the starter

For a gallon, I’d use roughly ½ cup of plain yogurt as a starting experiment.

Stir gently but thoroughly.

4. Put it into glass containers

Cover them.

5. Let them sit overnight

This is the part I’d experiment with.

Put them somewhere reasonably warm and undisturbed, rather than putting them in a yogurt machine.

For example, a turned-off microwave or oven can provide an enclosed, draft-free environment.

Don’t turn the oven on.

The idea isn’t to cook it.

It’s simply:

warm milk + yogurt bacteria + time

Then check it in the morning.

If it has gelled into yogurt, refrigerate it immediately.

There’s an important distinction about your woman’s method

She probably wasn’t deliberately fermenting it for 24–36 hours.

She may have done exactly what you now suspect:

evening → inoculate → cover → sleep → morning → refrigerator

That’s probably something like 8–12 hours.

And that’s much more typical.

The bacteria don’t need somebody standing there watching them.

One thing I’d definitely buy

A $10–15 digital instant-read thermometer.

That’s more important than a $100 yogurt maker.

Once you learn:

180°F → cool to ~110°F → inoculate

you’ll understand what the old woman’s finger was actually accomplishing.

Then, after you’ve made several batches, you may find yourself doing the same thing.

And there’s another fascinating experiment we can do

Since you have several gallons of milk, you could actually make this a controlled comparison.

For example:

Batch

Starter

Incubation

A

Store yogurt

Overnight at room temperature

B

Store yogurt

~110°F for 6–8 hr

C

Store yogurt

~110°F for 10–12 hr

D

Bulgarian heirloom

~110°F

E

Greek heirloom

~110°F

Then we’d compare:

• thickness

• tartness

• creaminess

• whey separation

• smell

• mouthfeel

• how well the next generation sets

• how long the culture remains vigorous

That would actually tell you whether you prefer the traditional method or the controlled method.

And because you have several gallons of milk, this is a perfect time to do it.

One other thing: don’t automatically buy “high-end” Bulgarian starter because it’s expensive. The interesting question is not whether it costs more; it’s whether you prefer the microbial culture and resulting yogurt. The heirloom Bulgarian cultures currently sold are specifically intended to be propagated batch after batch, so we can consider one later if your first experiments make you want to explore the culture itself.

If you want, we can make this into a  “David’s Greek Yogurt Project” and work through the whole thing —  milk selection,  starter bacteria,  containers,  exact first-batch recipe,  room-temperature vs 110°F fermentation,  straining vs unstrained Greek yogurt,  how to save starter,  how many generations you can perpetuate it, and eventually  whether a Bulgarian/Greek heirloom culture is worth buying.