Some (silly?) wild-yeast starter questions.
Slightly inspired by the sourdough starter thread; I have a few basic questions about a wild yeast starter that I have just started.
1) A lot of websites and books say to refresh the starter whenever it is "low". What exactly does low mean? Is there another way of testing whether it is time to refresh the starter (pH, consistency, etc.)?
2) I have heard people say that the time between refreshes grows as the culture becomes more established. Is this true in general? What sort of time frame are we talking about?
3) It is a whole-wheat starter, do you always need to feed the starter the same type of whole-wheat (e.g. hard red wheat)?
4) Finally, I have heard about people recommending the addition of baking soda or milk instead of water but neither are discussed in the book that I am using for guidance (Peter Reinhart's book). Can anyone give me a brief summary of what these are things are trying to accomplish?
Consider my extreme negligence, which I seem to get away with, but I cannot give anyone else a guarantee. I've had my starter (made from organic grapes and stems) for over ten years, and it can sometime sit in the fridge untouched for a year (I have dry spell in sourdough baking). After sitting that long, it is separated into a lower floury part and an upper portion that looks pretty gross, like gray water. I begin by stirring it all back together.
What I find is that awakening such a dormant starter is always successful, but it's a protracted business--figure on a week or more of intensive refreshing. After that process, it's robust and good as ever, and not different tasting, as best I can tell.
I got tired of feeding starters years ago. But my tip is that when you get one that you're happy with, smear a few tablespoons of it on a slipat or a piece of plastic wrap. Let it dry out completely then break it up and store it in an airtight container. I put them in vacuum seal bags and kept them in my freezer. This will be your insurance if anything happens to your starter.
If you need to use it, just rehydrate as you would commercial yeast and feed it as you did when it was a live starter. Then be sure to dry out your "insurance" again.
It takes a minimum of 3 days of being fed 3 times a day to initially get a new starter started. At that point, you starter should be ready to bake with if your starter is doubling in volume when you feed it.
Then it takes a while more for the starter to stabilize and fully establish itself - I like to feed my starters 2 - 3 times a day for about 2 weeks in order to fully stabilize the starter. This gives all the strains of yeast and lactobacilli a chance to "shake themselves out.
After that you can keep it in the refrigerator and bring it out early in the day before baking (or the day before) to refresh it and get it ready for baking. When your starter is established and you are maintaining it in the refrigerator, it shoud be refreshed weekly to keep it strong, healty and stabile.
I don't know why people would add things like baking soda or milk to their starters, other than that perhaps they don't have strong, healthy established starters and are experimenting to try to improve what they have. A strong, healthy starter only needs water and flour and the introduction of other ingredients makes the starter vulnerable to contamination - either by direct addition of ingredients containing foreign microbes or by changing the pH balance and weakening the desirable sourdough colonies.
A whole wheat starter can be converted to a white-wheat starter if that's what you want to do. If you want to maintain the starter as a whole wheat starter, if you switch the wheat you risk changing the mix of microbes in the starter so if you like your starter the way it is, feed it the same wheat. There's just no way of telling what will happen if you change the wheat - it may improve the starter, it may change it dramatically or it may not even be noticable. What you could do is put a portion of starter in a clean container and feed it some of the new wheat for a few feedings to make sure that it will fully activate and then bake with it. If you like the bread, then you can throw the earlier starter out. But if you don't like it, you'll still have your base starter to go back to.
I think the research indicates that an established starter is remarkably stable. I wouldn't expect there to be any difference in the flora of the starter whether refreshed with whole wheat flour or low extraction ("white") flour. Rye, on the other hand, carries a much greater variety of microflora. So if you turn the wheat starter into a rye starter and then move back to wheat, you can expect some differences in the strain of flora.
For a good lay person's discussion of the microbiology involved, see the appendix in Wing and Scott's book "The Bread Builders." For information on building and maintaining a culture, you can't do better than the chapter in Jeffrey Hamelman's "Bread: A Baker's Book of Techniques and Recipes." For something slightly less technical but still extraordinarily clear see Andrew Whitley's book "Bread Matters."
Your questions are not silly. Understanding your starter will take a lot of the frustration out of your bread making experience.
1. Once a starter is established, the refreshing (feeding) schedule depends on how it's stored. I feed my starter once a week, using a 1:1 formula (one part starter to one part refresher, consistent with the desired hydration level) and allow it to rest on the counter for one hour before returning it to the refrigerator where it lives in a loosely covered plastic refrigerator dish. I use about half of it each week to make bread and refresh it at the same time. It's a year old and doing well.
2. Nonsense ....
3. No; you can feed your starter with a type of flour that differs from the original formula but it will change the characteristics and the flavor of your bread.
4. Baking soda and/or milk will alter the PH. I would never add them to my starter. Which of the Reinhart books are you reading. The best one (IMO) for a beginner is The Bread Baker's Apprentice; provided the user starts at the beginning and works their way through the book front to back.
I have made two starters from the Reinhardt BBA book, the rye and sourdough. I keep both in plastic tubs in the fridge and just pull it out when I want that type of bread. For the regular starter, I have gone as long as two months without refreshing. To refresh, I divide the starter [but don't throw any away]. feed.... after a day, one goes back into the fridge, while the second gets another feed [if I have time] and I make the bread.
I have found that the starter, once happily stabilized and mature, is rather robust. I suspect that I am more negligent than "best practice" but the bread is good.
About the wheat, I use a combination of rye and white bread flour depending on the flavor profile of the bread I plan to make. I prefer rye to whole wheat, but I think this is a matter of taste only. I have never used milk or baking soda in my starter.