Best everyday jar
Ball wide-mouth quart jar
32 oz (about 950 ml), wide mouth
Clear glass, a mouth wide enough for a spoon and a spatula, and cheap enough to keep a spare for swapping in on cleaning day.
Sourdough starter jar: size, lid and where to keep it
Use a clear, wide-mouth jar of about 1 quart (32 oz) with a loose lid. That gives a 100 to 200 g starter room to double, lets you see the bubbles and the rise, and is easy to scrape clean. Keep it at 75 to 78°F to peak in about 4 to 8 hours, or in the fridge between bakes.
Jar: a 1 quart wide-mouth glass jar, lid resting on top or screwed on loosely. Where: a warm spot (75 to 78°F) when you are baking; the fridge if you bake once a week or less.
Our picks
Drawn to its outside size
Holds one quart jar between 41 and 122°F, so the starter keeps a more predictable rhythm in a cold or hot kitchen. No jar included.
Stir and scrape
Silicone spatula, narrow
Narrow silicone head
Reaches the bottom of the jar and scrapes the walls clean after each feed.
How we know: weights and sizes are the makers' published figures, linked from each product page, and a dough range marked “our estimate” is our arithmetic on them. We do not perform hands-on testing. How we compare.
Which jar
Clear glass lets you see the rise and the bubbles, which is how you tell when the starter is ready. A wide mouth makes stirring and scraping easy. Size it so the starter fills a third or less after feeding: a quart jar suits up to about 250 g of starter. Put a rubber band or a piece of tape at the level right after feeding.
| Starter kept | Jar | Room to rise |
|---|---|---|
| 50 to 100 g | 1 pint (16 oz) | Triples comfortably |
| 100 to 250 g | 1 quart (32 oz) | Doubles to triples |
| Building a levain of 300 to 500 g | 1.5 to 2 quart | Doubles |
The lid
A starter makes gas, so the lid must not seal tight. Rest the lid on top, screw it on loosely, or use a cloth or paper towel held with a rubber band. A tight lid on an active starter can push gas and starter out when you open it.
Temperature: the speed dial
At 75 to 78°F (24 to 26°C), a starter fed 1:1:1 (starter, flour, water by weight) usually peaks in 4 to 8 hours. In a 65 to 68°F kitchen it takes about half as long again, or more; in the fridge it slows almost to a stop, which is why you can keep it there for a week between feeds. A warm spot or a jar warmer makes feeds fit your day; the feeding calculator works out the amounts for the time you want.
Fridge or counter
Bake several times a week: keep it on the counter and feed it once or twice a day. Bake once a week or less: keep it in the fridge, feed it once a week, and take it out to feed it one or two times before you bake. A grey liquid on top (hooch) means it is hungry: pour it off or stir it in, and feed.
Clean jar, healthy starter
Every week or so, move the starter to a clean jar. Dried starter on the walls is where mould starts. Pink or orange streaks, fuzzy mould, or a smell that is not the usual sour or alcohol smell mean throw it out and start again; a sour or nail-polish smell only means it needs feeding; see starter problems.
Questions bakers ask
What size jar for a sourdough starter?
About 1 quart (32 oz) for a 100 to 250 g starter, so it has room to double or triple after feeding.
Should a sourdough starter jar be airtight?
No. Cover it loosely so the gas can escape; a loose lid or a cloth with a rubber band both work.
What temperature should I keep my starter?
75 to 78°F for a peak in about 4 to 8 hours after feeding; the fridge (about 38°F) to slow it down between bakes.
More equipment for this job
Keep what you own when it does the job. These are the other exact models we profile.
Weck 743 Mold Jar, 3/4 L (set of 6)
For a starter you can see and scrape out
Weck 743 Mold Jar, 3/4 L (set of 6)A straight-sided 3/4 L glass jar with a glass lid; the wide mouth lets a spatula reach every corner.
28.7 fl oz, 3 7/8 in wide opening
Drawn to its outside size
For a starter or levain with room to rise
Cambro CamSquare 2 qt Container (2SFSCW135)A clear 2 qt square tub with volume marks, low enough for a fridge shelf.
2 qt (1.9 L), 7.25 in square7.25 × 7.25 in outside