Sourdough Starter Info

the books, blogs and blah blah about sourdough often contradicts others' opinions, and sometimes even itself.  Some of it is exactly wrong, but there's no red flags. It's a muddle for the neophyte sourdough baker.

My advice is pick one method, and stick with it. In your case maybe Bourke Street Bakery, only because its location is near to you. However, I still recommend Debra Wink's pineapple juice approach.  Establishing a starter from scratch, i.e. relying on the natural bacteria and yeast associated with the flour used can be tricky. Merely adding water creates an environment that encourages both desired and undesired bacteria growth. Using pineapple juice tips the scale favoring the desired bacteria by increasing the acidity of the mixture compared to only water and flour.

Cooling: First, as long as the temperature is neither too hot nor too cold that it kills the desired bacteria there is no wrong temperature.  However, there are temperature ranges that are "best" for bacteria and yeast growth.  Furthermore, there is a practical temperature range wherein growth happens at a rates that are convenient and reasonably comfortable for the baker.  I can't offer you a corroborating reference, but I suspect the 76°F (24.4°C) specified/suggested in many, many bread formulae developed because it's convenient--yeast and bacteria growth happen at a moderate rate giving the baker time to do other things while dough ferments, or proofs--and a comfortable temperature to work in. It's also a temperature easily maintained in today's artifical environments. (I'll bet ancient bakers cycled between freezing before the WFO was lighted, and roasting when it was.)

I've chosen a fairly narrow convenient range 12°C to 28°C and a narrower comfort range 20°C to 25°C.  Both are convenient because I bulk ferment dough at 12°C in a closet I converted to a wine cooler, and I proof shaped loaves either at room temperature (20° - 25°) or in a proof box (home built) at 28°C. Although I live in an area where the temperature reaches 38° in the summer months and -2° in the winter months my home is cooled in the summer and heated in the winter. Your postings, while not specific, imply your home environment is sometimes not convenient nor comfortable. 

I'll repeat what I said in my first reply: yeast and bacteria are resilient. As long as they aren't killed by it, any temperature is ok with them. However, they behave differently at different temperatures, so we need to control their environment's temperatures to get them to do what we want them to, which, for the most part is to eat the dough's sugars, reproduce and disgorge gas and flavor-making compounds. Your summer night time temperatures (30°) are fine, the bacteria will love it, the yeast prefers slightly lower temperatures (28°) but it will do ok at 30°.  Furthermore, when the temperature fall further they will cool, and continue to do very well at 23°C, they'll just do it slightly slower. On the other hand 39° is a bit too high for your objectives (but it won't harm the beasties). That's a peak temperature however, and probably only sustains for a few hours in the afternoons. You could just put the starter in the shade and let it tough it out; it will survive. Nonetheless, I recommend you cool it, but that could simply be done with its container in a shallow bowl of cold water, or wrapped in a cloth kept dampened. Yes, building and maintaining a starter will be a bit more work for you than other home bakers, but its possible. Sourdough starter is resilient.

How long does starter HAVE to stay at room temperature?

I assumed your question related to building a new starter, and I'll answer it accordingly.

There is no "HAVE to", but it is CONVENIENT to develop a starter at room temperature--the beasties act rightly, and things happen at rates that please our psyches, but you could build a starter within the practical range of 10°C and 28°C, and the temperature could swing daily through that range. It wouldn't be "ideal", but it would work.  However, things get really slow when refrigerated. (< 4°C). You'll want to keep a new starter in the aforementioned range until its established. Once established you can store it in the refrigerator, feeding it at reduced, regular intervals.

"What does established  MEAN?" Sondra asks.

I will tell you what I think it means, but I'd remind you you'll find lots of other opinions. My description applies to a 100% hydrated starter. Also, the words are imprecise, not scientific; nonetheless, they may be helpful to your learning about your starter.

An established starter, within three or four hours after a feeding will have noticeably expanded (perhaps even doubled), and its surface will be speckled with bubbles. It's smell will be clean, pleasant to the nose, wheat-like or nutty, and may give a slight hint of acidity. A tiny drop on your tongue will have little flavor, but will likely have a sharp feel on the tongue due to its acidity. Its expansion will peak in six to eight hours, its surface will be "bumpy", contain many more bubbles more varying in size, and  will have collapsed slightly. The smell and taste will remain about the same, possibly more acidic.

A final note: Established starters in the same environment will generally behave the same way, but will have subtle, unique differences. I am a strong advocate of two principles: 1) To the extent you can treat your starter consistently, i.e., feed it the same type of flour, even the same brand. Use the same water; store it at the same temperature; feed it at the same intervals. 2) Observe its visible behavior: learn how it behaves.

Once you get one established, give me a shout. We'll talk about maintenance, and building formula-ready levain with it.

Merry Christmas! I can't imagine celebrating Christmas in 29° weather:-) It's forecast to be -2° here tonight.

David G