Sourdough Starter — Building & Maintaining

A working reference for the wild-yeast starter behind the everyday sourdough, whole wheat sourdough, 50/50 golden wheat sourdough, and the sourdough pancakes and waffles. A starter is just flour and water colonized by wild yeast and lactic-acid bacteria — feed it, and it leavens and flavors everything here.

All amounts assume 100% hydration — equal weights of flour and water — which is what these recipes are built around.

Building a starter from scratch

Roughly a week from flour and water to a bake-ready culture. Use a clear jar, and mark the level after each feed with a rubber band so you can see it rise.

Day 1: Mix 50g flour + 50g water in a jar. Cover loosely (a lid set on top, not sealed) and leave at warm room temperature (~75°F).
Days 2-3: You may see a few bubbles and smell something sharp or funky — that's normal early bacterial activity, not the yeast yet. Once a day, discard all but ~50g and feed with 50g flour + 50g water.
Days 4-6: Activity picks up and turns yeasty and pleasantly sour. Move to feeding twice a day (about every 12 hours), each time discarding down to ~50g and feeding 50g + 50g.
Day 7+ — ready when: It reliably doubles within 4-8 hours of feeding, is domed and full of bubbles, and smells tangy and yeasty (not sharp or like nail polish). That predictable rise-and-fall is the signal it can leaven bread.

Rye or whole wheat gets a brand-new starter going faster — see the flour section below.

Feeding & maintenance

The peak is what matters. After a feed, a healthy starter rises, domes, and then falls. The top of that rise — "peak" — is when it's most active and buoyant. The bread recipes call for starter at its ~6-hour peak; time your feed so it peaks when you need it.

Room-temperature (bake often): Feed once or twice a day, discarding down to a small amount (say 50g) and feeding at least 1:1:1 by weight (50g starter : 50g flour : 50g water). Keep it out and fed when you're baking every day or two.

Refrigerator (bake occasionally): Feed it, let it start to bubble at room temp for an hour or two, then cap and refrigerate. It goes dormant and needs feeding only about once a week. This is the low-maintenance default between bakes.

Waking it up before a bake: Take it out, discard down, and feed. Give it 1-2 feeds at room temperature over 12-24 hours until it's doubling reliably and peaking on schedule again before you build your dough. A neglected or cold starter often needs two feeds to bounce back.

Feeding ratios and timing: Bigger feeds (1:5:5) rise slower and peak later; smaller feeds (1:1:1) peak sooner. Warmth speeds everything up. Use ratio and temperature to steer when it peaks to fit your schedule — the same lever discussed in the bread recipes.

Discard

"Discard" is the portion you remove before feeding so the culture isn't diluted by its own volume. Options:

Toss it — simplest.
Save it — keep a jar in the fridge and use it in the sourdough pancakes or waffles, where a small amount inoculates an overnight ferment. (Note those recipes need only a little; a big discard-dump is a different, chemically-leavened approach.)

Discard is spent — it adds flavor and tang, not much lift — so recipes using a lot of it lean on baking soda/powder for rise.

Reading your starter

Hooch (a layer of grey liquid on top): it's hungry, not dead. Pour it off (or stir it in for more tang) and feed. Consistent hooch means feed more often.
Smell: tangy, yeasty, faintly boozy is good. Sharp acetone/nail-polish means it's very hungry — feed. Truly off, rotten, or any fuzzy mold (pink, orange, black) means throw it out and start over.
Sluggish rise: usually too cold, underfed, or a too-big feed on a weak culture. Warm it up, feed 1:1:1 more often, or add a little whole wheat or rye to boost it.

Flour types

Different flours feed the culture differently. All still target 100% hydration, but coarser whole grains drink more water, so you may nudge the water up to keep the same loose consistency.

White (all-purpose / bread flour): Mild, clean flavor and a slow, steady, predictable ferment — the easy baseline. Bread flour's higher protein gives a slightly more vigorous rise than all-purpose. A white starter is the most forgiving to read, since it doubles cleanly in a straight-sided jar.

Whole wheat: The bran and germ carry more wild yeast, bacteria, minerals, and enzymes, so a whole wheat starter is noticeably more active — it ferments faster, peaks sooner, and tastes tangier and nuttier. It also absorbs more water, so it can look stiffer at the same hydration; add a splash more water if you want it looser. A spoonful of whole wheat is the classic way to wake up or supercharge a sluggish white starter.

Rye: The most enzyme- and nutrient-rich of the three, and the fastest and most vigorous ferment — rye starters bubble up quickly and are prized for a deep, earthy tang. Rye is very thirsty and low in gluten, so a rye starter is stickier and more paste-like, and it may not dome and "double" as legibly as white — read it by bubbles and smell more than height. A little rye is the strongest jump-start for a new or tired culture.

Running a side-by-side comparison: Feeding a white and a whole wheat starter next to each other is a great way to see these differences. Keep both at the same hydration, same feed ratio, and same spot so temperature and schedule are controlled, and just watch: expect the whole wheat to peak earlier, rise more exuberantly, and smell tangier. When you add a rye starter to the lineup later, expect it to be the quickest and most bubbly of the three, and the hardest to judge by height alone — lean on bubbles, aroma, and the rubber-band mark. Whichever you bake with, the recipe hydration may want a small tweak: whole wheat and rye both drink more water than white.

Quick reference

Hydration: 100% (equal weights flour and water)
Ready to bake: doubles in 4-8 hours, domed and bubbly, tangy-yeasty smell
Use at: peak (top of the rise — ~6 hours after feeding for the bread recipes)
Room temp: feed 1-2× per day
Fridge: feed ~weekly; wake with 1-2 feeds before baking
Boost a weak starter: warmth + more frequent 1:1:1 feeds, or a little whole wheat or rye
Discard uses: sourdough pancakes, sourdough waffles

Source

Family reference notes