Starter
This starter is about 5 years old, It is due to be fed, but you can see where it was previously active and bubbling up the glass- a good sign.
Creating a starter like this just requires a jar, some flour and a lot of patience in the early days, but it is worth perservering. The alternative is to ask a local artisan baker if you may buy some starter.
Opinions seem to be divided as to where the yeast spores originate, in the flour or in the air. My instinct says both, but mainly the air. This means no two starters will be identical and each is closely related to the location.
Day #1, add 50g flour and 50g water in to a clean jar, stir, cover with light cloth or even sit the jar lid on top but not closed. Leave it somewhere warm but not hot, a kitchen cupboard is ideal
Day #2, add 50g flour and 50g water, stir, cover and leave
Day #3, same as day#2.
Day #4, should now have 300g of water/flour. Pour away 100g and feed with fresh 50g flour and 50g water.
Day #5- #7 same as day #4, except, you should be starting to see and smell activity... it will be frothy, thinner consistency and smell a little sour. If not, keep going (see also problems section)
Once you have a healthy starter, instead of throwing out the 100g this is used for your bread (see bread recipes)
If wished, you can now split off some of the starter and freeze it (in case you want to stop/ restart or main batch dies). To re-use, just defrost slowly then feed- should be fine the next day.
More importatly, you can now put the lid on after feeding, put it in the fridge and reduce feeding to one a week (or even less)