Until a few weeks ago, I didn’t know that the skin of fruit had yeast on it that could be harvested and multiplied, and then used to make bread that has hints of fruit flavor, a tender crumb, and all the beauty and science-fun of natural leavening.
I learned about this process from someone on the Breadtopia message board. He explained that organic raisins are the best bet for wild yeasts and answered my numerous questions on the process of making yeast water.
I also attended a lecture on the yeast life cycle given by my beer-brewing husband (in our kitchen, audience of me). He reads entire books about yeast, and urged me to do the same. I’m adding Yeast: The Practical Guide to Beer Fermentation to my TBR list, but not at the top (shhhh).
Now that I’ve written this blog, I agree with him that it’s hard to know where to start when explaining a circular process, but you have to start somewhere.
CREATING A YEAST WATER CULTURE
Fill a clean glass jar (1.5 pints, 710 ml) with a couple of handfuls of organic raisins and filtered water. Other fruit aside from raisins can be used to make yeast water. For example, I ended up using non-organic dates. But if the fruit has been treated with something to prevent discoloration or decay (e.g. the antimicrobial, sulphur dioxide), the process won’t work. See mini gallery below for moldy failure of treated raisins on day 5.
Cover, but not tightly/do not seal, and let sit at room temp for 5-7 days.
You will see fizzy bubbles forming on the fruit itself, and then collecting at the top of the jar as the days pass. At this point you can use the water to leaven bread.
From left to right: day 0, 1, 2, 3, 5.
MAINTAINING YOUR YEAST CULTURE
When you’re ready to bake, pour the water through a colander into another glass container (preferably with measuring marks and a spout). Toss the old raisins/fruit.
If you see dark brown silt at the bottom of your jar, rinse it out, as this dead yeast can impart some umami flavors (glutamic acid…marmite). Or keep it if that’s your thing.
Beige sludge is live yeast and doesn’t need to be rinsed out, though doing so is fine too, as the water itself has yeast also.
Pour back into the jar one-third to one-half of the yeast water (about 1 cup, 240 ml).
Add some fresh cut up apple or other sugar source.
Fill to top with fresh filtered water and leave on the counter at room temperature for a few hours to help stabilize the yeast in this new food environment.
Your yeast creatures are in different stages of their life cycle, and in some of these stages, a big shock of temperature or food supply can be fatal. :0
This is yeast water that has been freshly fed and sat at room temp for 10 hours (longer than necessary).
After a few hours, put the jar in the fridge unless you plan to bake with it every 1-2 days.
Even if you’re not going to bake, after a week in the fridge, you should strain out the old fruit and put in new fruit.
BAKING WITH YOUR YEAST WATER
With the 1 to 1.5 cups (~236-355 ml) of yeast water you’ve retained to use, you can bake one or more loaves of bread, depending on how long you’re willing to wait for fermentation, and if you want to combine it with sourdough starter or not.
If coming from the fridge, take the yeast water out several hours before you plan to mix the dough, to warm up and bring out of dormancy the yeast. You should see fizzy bubbles again when it is ready to use.
Below are three yeast water recipes I made with their different fermentation times and ingredient ratios.
WHITE FLOUR BOULE
BULK FERMENTATION: 10 hours 76F/24C
FINAL PROOF: 9 hours refrigerator
500g flour (350 bread flour, 150 all purpose)
260g date yeast water
PART WHOLE GRAIN SPELT BATARD
BULK FERMENTATION: 19 hours refrigerator, 11.5 hours 74F/23C
FINAL PROOF: 1 hour 80F/27C
500g flour (300 whole grain spelt, 200 bread flour)
265g apple yeast water
APPLE, ALMOND, ORANGE PEEL KAMUT BOULE
BULK FERMENTATION: 6.5 hours room temp (exact temp unknown)
FINAL PROOF: 12 hours refrigerator
500g flour (350 bread flour, 150 whole grain kamut)
230g apple yeast water
75g mature sourdough starter
125g cooked apple (not strained)
100g chopped candied orange peel
75g chopped blanched almonds
1/4 tsp ground cinnamon
1/8 tsp ground cardamom