Wild grape sourdough starter: what's the story?

When I first began baking with sourdough, I remember hearing older bakers talk about creating a new starter by first burying wild grapes in the flour they planned to use. Wild grape sourdough starter, while it wouldn’t ultimately perform any differently than starter created with “un-graped” flour and water, would become active more quickly, they said.

I never did try making that wild grape sourdough starter — until now.

Grape sourdough starter via @kingarthurflour

The other morning, walking through a wild meadow with my dogs, I suddenly caught a whiff of grapes on the warm, humid air. I looked around and, sure enough, poking out of a thicket were the telltale heart-shaped leaves of grapevines.

Grape sourdough starter via @kingarthurflour

I pulled aside brambles and twigs to find beautifully ripe grapes, some just starting to soften, others plump and firm. Eating a few, I found them thick-skinned and seedy, but wonderfully sweet.

Wild grape sourdough starter — if not now, when? Click To Tweet

Grabbing a handful of grapes, I headed home along the salt marsh, carefully holding them by the stem so as not to disturb their skin.

What’s up with that? The skin of wild grapes (as well as berries) is positively seductive to wild yeast. Wild yeast floating in the air will collect on grape skins. So legend has it that burying wild grapes in flour will transfer some of that wild yeast to the sourdough starter you make with the flour.

Let’s see what happens.

Grape sourdough starter via @kingarthurflour

“Graping” the flour

Here I’ve buried a small handful of grapes in a scant 1 cup (4 ounces) of King Arthur Unbleached All-Purpose Flour. I’ll leave them in the flour overnight, then remove them when I’m ready to make my starter.

Disclaimer: This isn’t strict science. I didn’t weigh the grapes, nor did I ascertain what type they are, nor “vet” them for their wild yeast content. This is simply a seat-of-the-pants food experiment — one which I encourage you to perform yourself, should you get the chance.

I’ll compare my grape-enhanced flour against King Arthur White Whole Wheat Flour and plain King Arthur all-purpose flour.

Why the whole wheat flour? Starter created from whole wheat or rye flour quickly becomes active for the same reason grape-flour starter would: the microflorae in whole grains are attractive to wild yeast.

Grape sourdough starter via @kingarthurflour

Three flours, three starters

Putting 4 ounces of each type of flour in three different jars, I add 4 ounces of cool water, lay the jar lids loosely on top, and set the jars on the counter.

Grape sourdough starter via @kingarthurflour

The second feeding

Twenty-four hours later, the starters are beginning to work. At this point, the grape-flour starter (left) and plain flour starter (right) are a bit behind the whole wheat starter (center).

Look at the bubbles in each, though. It always amazes me that flour and water, given time, can become a bread leavener — a.k.a. sourdough starter.

I discard all but 4 ounces of starter from each jar, feed them each a scant 1 cup (4 ounces) of unbleached all-purpose flour and 4 ounces of water, and walk away, expecting I’ll feed them again the next day.

Grape sourdough starter via @kingarthurflour

A few hours later

But within just seven hours … oh, my, look at those starters go!

The grape sourdough starter and plain starter are neck and neck, nearly to the top of their respective jars. But the whole wheat starter has poked its lid off and is starting to ooze onto the counter. The whole wheat starter has clearly maintained (and even increased) its early lead.

The takeaway

What can I conclude from this experiment?

There’s nothing wrong with burying wild grapes in flour and making a grape sourdough starter; it should perform well.

But if you’re looking for a fast start, begin with whole-grain flour, such as wheat or rye. You don’t need to continue to feed your starter with whole grains. But using wheat or rye as the vehicle for first attracting and trapping wild yeast is a smart choice.

As is taking your starter and making a loaf of Rustic Sourdough Bread.

Grape sourdough starter via @kingarthurflour

Want to make your own sourdough starter from scratch? See our blog post, How to make your own sourdough starter. And learn everything you need to know about sourdough baking in our sourdough baking guide.

PJ Hamel

PJ Hamel grew up in New England, graduated from Brown University, and was a Maine journalist before joining King Arthur Flour in 1990. PJ bakes and writes from her home on Cape Cod, where she enjoys beach-walking, her husband, two dogs, and really good food!


  1. Andrea Frank

    My son (then in 3rd grade) and I, of course, set up a whole science fair project doing exactly this. A difference is that he soaked the grapes (and also organic apple peels and dried fruits) in water which was then used to make the starters. I made bread every day from the discards. We ditched the science after the fair and kept one starter going for many months. What I loved was how the starters smelled from day to day- sometimes like honey, or beer or orchards- or sour sour sour! After the commitment to science was over, we also ditched recipes and measurements. All of our breads were made by whim and feel- a rye one day, whole wheat on another, pancakes to rustic accompaniments to hearty soups… Only a couple out of maybe 60+ loaves were duds. Really fun. All the talk about poolish, biga, chefs and lelvain has a place, I guess, but making bread is not that hard at all.

  2. Cedarglen

    Thanks PJM. By any measure you are a genius.
    I have a few wild grapes on my property, just now past their prime for eating, yet ideal for a new starter. Ahem… Saturday morning’s first project I think. With multiple types of flour in the pantry, I can make nearly anything. From the looks of it, the wild grape yeast is ideal for any flour, targeted for sourdough, so why not?
    Even at my advanced age, I can be impatient and at least one of the creations will allow me to bake something on Sunday afternoon. Does it get any better? Thanks for your post > one year ago.

  3. Hilary

    When this was first published a year ago I tried it because I was curious and I had grapes. I am not a good break maker. No-knead is the only thing that ever works and I’ve even made some doozies with that, so sourdough was a stretch for me.

    But, after a little more than a year, many bricks, some passable loaves (made with “assistant yeast”), a couple of near-death experiences for my starter (once made over a cup of alcohol and it took a month for it to recover) and an awful lot of flour, something finally turned the corner and I have successfully, FOUR times in a row, made an amazing, well-risen loaf of bread using only the starter, flour, water and a little salt.

    So thank you for the initiative, and for those who are in despair that it will never work, it can, and it’s worth it!

    But you will invest heavily in flour, much of which ends up in the trash. Or the compost pile.

    1. Andrea

      Don’t trash your starter- make something with it. That’s the mistake a lot of folks make. Take what you removed when you fed it, treat it like biga or any preferment and make a loaf of bread- or rolls or whatever. You can do this the very first time, it just won’t have the sourness you are looking for yet. You may also experience some ups and downs of vigor from your starter as it is developing lactic bacteria colonies as well as yeast- kind up like cycling a fish tank- but don’t think on that image too much because were’ talking about food. Seriously, though, you can use the starter as you remove it. This is a fun way to really get intimate with the development of your sour dough.

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