How to rise and bake a sourdough loaf in the least amount of time?

Shorten the intervals for feeding, prove in a warm environment, use a high LA starter to begin with, (mine started life as a mix of live yoghurt, wheat flour& an apple from my garden). Highly acidic stable leavenings can be faster... Mine doubles in size in 2hrs.

Just take some of the commercial bread making tricks and add them to your process. If you keep a mature starter in your fridge, you can add some to sour the flavour of the bread, while using commercial yeast, or even baking soda to leaven the bread. The baking soda reacts with the acids in the starter to produce gasses. Check out a sourdough pancake recipe which uses baking soda to get the feel for this. Also, google "quick bread", which is a name for breads which use non-yeast rising agents such as baking soda - you can replace some of the flour and water in these recipes with starter to add the sour taste.

If you've only got a few tablespoons of starter to begin with, then there's not a lot you'll be able to do -- ordinarily it would take a couple days to feed and multiply that starter enough to be able to bake a loaf of bread from it. Even then, true sourdough starters tend to rise much more lazily than commercial yeast, so even with a large quantity of starter it would be hard to go from start to on-the-table in three hours.

However, this is assuming you're using only sourdough starter to rise your bread. If you were to make bread using the starter and spike it with a normal amount of commercial yeast , you'll get some of the sourdough characteristics from the lactic acid in the sourdough culture, with the fast rise and predictability of the commercial yeast -- you're essentially bypassing the yeast part of the sourdough starter and using all-commercial for rising.

To save time, you could maybe do a straight rise, where you go from mixing directly to final shaping/proofing and skip the initial rise. It will give you a more rustic texture, but hey, you wanted fast. Rose Beranbaum has a prosciutto ring bread that's a straight rise and turns out pretty well.

I don't know that any of your other ideas are likely to save you a significant amount of time -- tweaking how you mix the dough isn't going to help a lot. Though making smaller loaves will decrease your baking time.

Good question. A more liquid dough is generally quicker to ferment. So use a high hydration dough and bake inside a mold. Never start baking from a low temperature - as far as I know this is disastrous. Keeping the process or at least proofing at 25-28 degrees Celsius will speed it all. If possible, make in advance a good amount of starter (such as 300g for a loaf using 500g flour) to use when at the highest rise - a little planning to have it ready at the time you can start making the bread. Also I’d mix, then rest the dough for just 20 min, knead 5 minutes and shape immediately and proof.

If I need a quick sourdough style bread I would normally add a 3-4 tablespoons of my sourdough starter into normal yeast bread. Sourdough should be at least 24 hours since last feed.

In the morning I add my starter to all the water in the recipe. Then I add roughly equal weight in flour(wheat). Sometimes I put a cup of white flour in the end. My starter is 100% wheat. I take a table spoon out of the 50 50 mix before making the bread at night. Add flour and water to keep my mother. After I get done milking the cows I make my loaves. I put the oven to 90c with loaves in and a pan of already boiled water. Turn oven off once reaches 90c turn it on and off periodically to keep it warm. Proof for 2 to 3 hours. Bake 180 45-60min.

Also I don't have anything to back this up. I routinely let my starter almost die. Then I put a spoon into a new starter mix. It started after numerous times of near accidental death and I found the starter to just grow in flavor and rise strength after I revive it. Maybe the last living yeasts are just the fittest who survived. Maybe It's all in my head.

that's hilarious and may very well be true. I think along your method too.

For a less sour and faster rise, i maximize the "starter" by feeding my starter all the water and about half the yeast of the recipe. It's basically the sponge method. My original goal was to push towards white bread but speed is a nice thing too. It's still not a 3-4 hour deal, even if i streamline as much as possible.

The night before i feed the starter all the water and half the flour. That'll float after about 8hrs on the counter or 4-5 in the oven with the light. I finish adding the rest of the flour and knead and then proof for 4-6hrs in the oven. The higher starter ratio definitely helps the rise speed but it's still not speedy.

I'm testing with speeding this up even more with some baking soda just before kneading. The baking soda can apparently hurt the starter yeast by changing ph but help the rise during final baking so I'm playing with it and i can't speak authoritatively. But I'll say this. If i do what I've described, peak rise with maximum starter and baking soda before proofing, then i shorten the proofing to 3 hours(not a full rise at all), knock it down, shape it, 1 hr final rise, bake it, i get a decent hardy bread by dinner. It's like a soft ciabatta.

The next step in my logic is to use past peak starter, 12 hours in the oven with the light on when it's fallen back down a bit, because it's more acidic so the baking soda will rise more and mess with the ph less. The baking soda seems to improve the rise speed during proofing though I've read it requires the heat from baking so i figure increasing that reaction with higher acid will confirm my suspicion.

My other ideas are adding sugar to the sponge stage to feed the yeast faster and folding during proofing but my goal is a burger bun/dinner roll crust and crumb more than just a speedy rise.