A while back, I was reading an online bulletin where people were discussing the pros and cons of using different types of flour in their sourdough starter.
Someone was agonizing because they realized the starter they just brought home was a white-flour starter. What they hadn't realized is that white flour is enriched with who knows what, and bleached, it's devoid of nutrients, it turns straight to sugar in your stomach and brings the plague on your house when you eat it.
- I said I don't think white flour is the devil.
- I said if you don't like the flour in your starter, it's okay, you're not stuck with it.*
- I didn't say, why did you buy it? Cheaper to make your own.
* You can change the composition of your starter any time you want. Each time you feed it, you remove half, either discarding it or baking with it, and replace it with the same amount of flour and water, fresh. If you want to change what the starter is made of, change what you feed it. It won't take many feedings to replace the original at that rate.
Anyway, the white flour thing is funny to me. I mean I get it. Highly-processed, bleached flour isn't great. But neither is highly-processed, bleached salt. That doesn't mean white flour is bad, any more than it means salt is bad. It just means you should steer toward a non-bleached, quality version whenever you can. My grocery happens to sell Bob's Red Mill. No complaints.
That said, I often prefer to use a big percentage of whole wheat when I bake, because it's more nutritious and creates heartier, more complex flavors. But sometimes I use white too. True, the bran's been removed. And true, what's left is less nutritious. And yeah, it transforms to sugar when you eat it: good to know.* Still doesn't mean white flour will defile you if you touch it.
* I read recently that the glycemic index of sourdough is lower than that of bread made with active dry yeast. If so, maybe, to some extent, the fact that you're making slow bread makes white flour's transformation to glycogen in your blood a little slower too. Look it up if you're interested — then come back and tell me what you learned in a comment.
The trick is to know what a given flour offers, so you can get what you want from it. Which brings us to your sourdough: what will you feed your starter? Here are the flours I've tried, and what I think of them.
White Flour Starter
I find the texture of a white flour starter to be stretchy and soupy, not interested in holding its shape or making much of a statement. Flabby is the word. Also, the cultures work through it pretty quickly; I wonder if that's because the sugar is more available, or more highly concentrated, something like that. This can be a bonus if you want to jumpstart your starter for some reason: revive it in fast-forward. Or if you're out of your regular flour, and the culture needs to eat. Otherwise this option doesn't interest me. White flour is great for baking certain things; not so great as a starter.
Whole-wheat Flour Starter
Whole wheat is my go-to. It's a workhorse. When fed whole wheat, my starter is soft but dense, elastic but substantive. It's easy to stir, but it doesn't pour or spill about.
As mentioned above, it's also more nutritious than white, but seriously, your starter is such a small portion of the finished food, is there really enough bran in there to matter? Its job is to introduce tons of microcultures to your food, not tons of bran. If you really want to eat some bran, your choice of baking flour matters much more than your choice of starter flour.
Next observation, whole wheat is a little slower to ferment; the cultures take longer to work through it. I appreciate this. I want my culture to be able to play by itself a while.
Finally — this can be good or bad — a whole-wheat starter imparts a whole-wheat flavor. This is fine most of the time, but there are times I don't want the statement. And although the starter represents a small portion of the total ingredients, the strength of that flavor can come through.
Rye Flour Starter
Whole-rye flour brings all the benefits of whole wheat, plus one additional benefit and one additional drawback.
Its perfume is delicious. Delicious. When I was using rye flour all the time, its aroma was just ... if they made a perfume with that fragrance, I'd be wearing it now.
On the downside, its texture is cakier than wheat. This is not a problem if you're just using it to feed your starter, but when I was baking whole loaves with nothing but rye flour, I found the dough was chunkier and less elastic. Later, the finished loaf was less amenable to slicing.
I don't use rye in my starter anymore, but it's still my favorite choice. So, why don't I use it? I don't have counter space right now for an extra flour jar.
Have you tried other flours in your starter? If so, share what you tried and what you thought about it.