San Francisco Sourdough Instruction

Millions of first-timers have made incredible bread with the packet in your hand. No experience needed — if you can stir, you can do this.

⏱ ~5 minutes a day🍞 First loaf in about a week

Before you start

Grab these first

You probably have most of it already.

Your starter packet The one in your hand

Flour Organic bread flour gives the highest rise — all-purpose works too

Water without chlorine or fluoride Bottled spring water is the easy button

A quart-size glass jar

A coffee filter or thin cloth + rubber band

Something to stir with

A kitchen scale Optional — but grams make every feeding precise

Using all-purpose flour? Flip this and we'll swap the feeding schedule for you.

Everything you need to get started: starter packet, flour, measured water, quart glass jar, cloth cover, rubber band, and a spatula

60 seconds

See it before you start

From packet to finished loaf — watch how easy the whole process really is.

The steps

Day by day

Check off each day as you go — the page remembers where you are.

All-purpose flour schedule (swapped in) Good news — it's the same ratio of flour and water. Follow this chart (amounts in Tbsp):

Feed	Starter	Flour	+ Water
#1	Whole packet	1 Tbsp	1 Tbsp
#2	Entire starter	2 Tbsp	1 Tbsp
#3	Entire starter	4 Tbsp	3 Tbsp
#4	Entire starter	8 Tbsp	6 Tbsp
#5	Keep 8 Tbsp	8 Tbsp	4 Tbsp
#6	Keep 8 Tbsp	8 Tbsp	4 Tbsp

Pro tip: stir like you mean it. At every feeding, stir vigorously until every streak of flour disappears — it works air into the starter, and those air pockets help it rise. A Danish dough whisk is the best tool for the job → sourdough tools

DAY 1

Done

Wake it up (5 min)

Stir your whole packet into 8 g flour (about 1 Tbsp) and 15 g room-temperature water (about 1 Tbsp) in your glass jar. Cover with the coffee filter and rubber band, and let it sit undisturbed somewhere warm (75–85°F) for 12 hours.

Day 1 starter paste in a mason jar: thick, smooth, well mixed - this is what right looks like

What you'll see: honestly, not much yet — a thick paste. That's exactly right.

DAY 2

Done

First feeding

Feed the entire starter 16 g flour (about 2 Tbsp) and 15 g water (about 1 Tbsp). Stir thoroughly, cover, and let it ferment for 12–24 hours.

What you'll see: maybe a few tiny bubbles. See them? That's your starter coming to life. You're doing it right.

DAY 3

Done

It starts to grow

Feed the entire starter 32 g flour (about 1/4 cup) and 45 g water (about 3 Tbsp). Stir thoroughly, cover, and ferment for 12–24 hours.

Stirring the starter thoroughly after its Day 3 feeding

What you'll see: more bubbles, and a fresh, slightly tangy smell.

DAY 4

Done

Bigger meals

Still no discarding — feed the entire starter 64 g flour (about 1/2 cup) and 90 g water (about 6 Tbsp). Stir thoroughly, cover, and ferment for 12–24 hours.

The starter resting covered in its jar after the Day 4 feeding

DAY 5+

Done

The home stretch

Discard down to 125 g of starter (about 1/2 cup), then feed it 64 g flour (about 1/2 cup) and 60 g water (about 1/4 cup). Stir, cover, and ferment 24 hours — then repeat every 12–24 hours at least 2 more times.

The starter risen and full of bubbles throughout — ready to bake with

THE FINISH LINE

How you'll know it's ready

It rises within 4–8 hours of a feeding, has visible bubbles throughout, and smells pleasantly tangy. Rising like clockwork? Congratulations — you just made a San Francisco sourdough starter. Time to bake.

Don't panic

Is this normal?

Almost always: yes. Tap your question.

No bubbles after 24 hours — is it dead?

Nope. A cool kitchen just means a slow start. Move the jar somewhere warmer — on top of the fridge, or in the oven with just the light on — and give it another day.

There's grey liquid on top

Harmless — that's just your starter telling you it's hungry. Stir it back in and feed as usual. Mold looks different: any pink, green, blue, or white fuzzy patches on top mean the starter has molded — toss it and email us, we'll make it right.

It smells like vinegar or nail polish

Hungry, not ruined. A feeding or two and the smell mellows into pleasantly tangy.

It rose, then collapsed

That's the natural rhythm. The peak usually hits around 4–6 hours after a feeding — you likely just caught it on the way down. Keep feeding and watch the timing.

Do I really have to throw some away?

You don't! That extra is called discard, and it makes ridiculous waffles, pizza crust, and crackers → discard recipes

Fuzzy patches — pink, green, blue, or white

The one real stop sign. Fuzz in any color means mold — toss the starter and email us at info@culturesforhealth.com. We'll make it right.

Was this helpful?

After the first week

Your starter lives here now

Bake a lot?

Keep it on the counter and feed it once every 24 hours: 1 part starter, 0.5 part flour, 0.5 part water by weight (about 1 part starter, 1 part flour, 0.5 part water by volume). Aim for thick pancake batter — too dry, stir in 1 Tbsp water; too thin, 1 Tbsp flour.

Bake weekly-ish?

Keep it in the fridge — cold makes it hibernate. Feed it every 5–7 days with the same ratio.

Baking day

Feed without discarding to build up what your recipe needs. It's ready to bake within 4 hours after the last feeding — just always keep 1/4 cup back to keep the streak alive.

ONE PACKET, ENDLESS BREAD — your grandkids could still be using this starter.

Stuck? Ask a real person.

We've helped millions of first-timers through this exact week. You will not break it — promise. Email a photo of your jar to info@culturesforhealth.com and we'll tell you what's going on.

✉️ Email us

We usually reply within a few hours

Starter's ready?