I wanted to give a go at baking some sourdough bread. As I read various (non home brewing) websites on how best to make a starter I had to check in here.
It seems many people try and make/ maintain wild starters with so so results. Would a commercial lacto starter be a better way to go?
I'm sure there's a little carryover from beerbrewing lacto cultures and those found in sourdough starters, but not enough to warrant it use, IMO. Not to mention, a sourdough starter contains some wild yeast (candida typically) too, not just the several species of lactobacillus. It's a mixed culture.
The process of creating a sourdough starter from scratch is quite simple using rye flour (Hodgson Mills, Bobs Red Mill, etc). Mix equal weight rye flour and water (say 25g each). Wait 12 hours, remove half, add 25g each rye flour and water (not you have 75g total; 25s+25f+25w). Repeat process every 12 hours for about 9 days. By about day 7-9 you will have a starter that should leaven a loaf of bread, and that was created completely from scratch using nothing more than flour, water, and time (it's pretty cool actually!).
Following this process, you'll find that the starter bubbles up quickly within 24-48 hours and will smell clean, maybe a little fruity, and of wet flour. Then a day later it does nothing for 1-2 days, and starts to smell of garbage and rotting grossness. Then after that, it will begin bubbling up again but more slowly; as time goes by, it will happen more and more quickly. The smell will move from garbage to more vinegary as the days go on. At this point, about day 7-9, it's ready for baking.
From that point (day 9ish), you want to really help the starter to become strong and stabilize (of course, you can be baking with it throughout this entire time). This just means maintaining a 12 or 24hour feeding regime for a little while longer (9-14 days more). Once you've established a strong, reliable, and resilient starter then you can look at refrigerating it to minimize the feeding effort. Often times, a refrigerated starter can go anywhere from a couple weeks to few months between feedings depending on varying specifics and treatment.
To help push the starter into a 24 hour cycle instead of the 12hr cycle you're on, you need to give it more food and make a thicker environment for it to work. This is accomplished by using a different ratio of starter, flour, and water. You've been doing 25 starter, 25 water, and 25 flour (1 to 1 to 1 or 1:1:1). What I've done is move to a 1:3:4 ratio, which makes a thicker starter with less initial innoculant (therefore, fewer initial bugs and more food means it takes longer to eat it all). Also, instead of moving UP in ingredients, I scaled back. For instance, 5g starter, 15g water, 20g flour (5:15:20 = 1:3:4) so I'm only maintaining 40g of starter at all times. When I'm ready to make some bread, I use a portion of this to build a larger "levain" (starter) in a different container that will be used for the bread, all the while maintaining my original starter in it's original little container.
You can convert the starter to an all white starter too if you find that easier, but the feedings in the fridge won't last as long; and the conversion needs to take place gradually (over the course of a week or two) to avoid shocking the mixed culture.
When I made a new starter a few months back, after a many-year hiatus, I baked a loaf using my Day 8 starter and it worked out very well. The pineapple juice, mentioned above in Denny's post, just helps to avoid the garbage/gross phase by preacidifying the starter. It doesn't necessarily get you to a ready starter any sooner, nor does it produce a starter that has different character.
Edit: Added some extra info on ratio feeding.
These are the two starters I maintain: