Feeding is just giving your culture fresh flour and water on a schedule that matches how fast it eats. Get the ratio and timing roughly right and a starter will stay strong for years. Here is the practical version.
Open the free starter log →A feed has two steps. First, discard most of the starter so you are left with a small amount — keeping 20–50g is plenty. Then add fresh flour and water. Discarding matters: it keeps acidity from building up and stops your jar from growing endlessly. The leftover discard is great for pancakes or crackers, so it need not be wasted.
A ratio is written starter : flour : water by weight.
Bigger ratios mean more food per yeast cell, so the culture takes longer to climb but stays milder and lasts longer between feeds.
If you bake often, keep the starter at room temperature and feed once or twice a day, watching for it to roughly double and then begin to fall. If you bake occasionally, store it in the fridge: feed it, let it start rising for an hour or two on the counter, then chill it. Cold slows everything dramatically, so a fridged starter only needs feeding about weekly. To bake, take it out, do one or two room-temperature feeds until it is bubbly and peaking, then use it.
Use a starter at or just before its peak — domed, bubbly, and roughly doubled, often passing the float test. A starter that has already collapsed back is still usable but weaker; feed it and wait again for the strongest rise.
Writing down the ratio, flour and peak time turns guesswork into a routine. Over a couple of weeks you will know exactly how long your starter takes to peak at your kitchen temperature.
Log feedings & ratios — free →