Sourdough Plum Pie {Kuchen}

I have this torn-out and almost colorless page with Plum Kuchen recipe from an old Gourmet Magazine, that many moons ago I used to regularly make as written. I always loved the sweet rich dough and juicy, almost caramelized plums that give this dessert its strikingly beautiful color.

As the years went by, the recipe has evolved to accommodate my current preferences, and dare I say higher nutritional standards. I finally went through the weeds of my scribbles and decided to contain the recipe in one spot – my blog, that is.

I use sourdough starter to leaven the dough, which is more like batter in consistency. I like to add 50% of whole grain flour – these days it’s Kamut wheat, or barley, or more often the combination of both. Kamut and barley don’t change the color of the dough into darker brown and don’t add toughness that comes with whole grains, so they work great in this recipe. Kamut also adds buttery tenderness that’s not entirely typical of yeasted enriched doughs.

I reduced the sugar to the point where sourdough plum pie tastes just right to me. If your palate is used to a lot of sugar, you definitely need to increase sugar in dough to 1 cup.

WHAT IS PLUM PIE (KUCHEN)

Plum Kuchen, or Pflaumenkuchen, is a German sheet pie, most often prepared with yeasted dough, but it can also be made with shortbread dough. It is a summer dessert, studded with fresh pitted plums, usually Italian prunes.

Yeasted pies are popular in my native Russia, and that’s what first caught my eye about this recipe. There is a bazillion versions of Plum Kuchen out there – I certainly don’t claim authenticity. This is simply my version of a plum pie that was inspired by the German Plum Kuchen.

WHAT IS SOURDOUGH AND WHY USE IT

Sourdough is a mixture of flour and water. Flour has yeast and bacteria naturally present within it; and when mixed with water, an environment favorable for growth of microorganisms is created. Naturally occurring enzyme amylase starts converting starch into sugar.

Bacteria, lactobacilli mostly, eat the sugar, and the by-product of that fermentation is consumed by yeast. Again, the by-product of all that together is carbon dioxide, which is what leavens the dough. Much like commercial yeast, sourdough starter is added to dough where it works to give rise to breads.

Unlike commercial yeast, sourdough rye starter works to make breads more nutritious and easier digestible. It breaks down grain proteins and sugars into simpler compounds. It also enriches dough with by-products of its metabolism – additional vitamins and minerals that were not originally present in the flour.

Here is my recipe for Sourdough Starter, you can use any type of flour with it.

WHAT IS KAMUT WHEAT

Kamut, Triticum turgidum ssp. turanicum, commonly khorasan wheat, is an ancient relative of regular wheat. It has avoided hybridization that resulted in modern wheat changing its genetic composition to become high-yielding, flavor-lacking, hull-less crops, which need to be protected via large quantities of pesticides. 

Kamut is a registered trademark of a company that brought the grain to market. It’s a pretty neat story of how it all started that you can find here. 

Kamut berry is a lot larger in size than modern wheat berry. It is also nutritionally superior – it contains 40% more protein, and exponentially more antioxidants. It is easier digestible than modern wheat, and maybe a good alternative if you always feel discomfort and bloating after eating wheat.

HOW TO MAKE SOURDOUGH PLUM PIE (KUCHEN)

Ingredients

• 1/2 cup (115g) sourdough starter
• 1 cup (240g) kefir or buttermilk, room temperature
• 1 egg, room temperature
• 1/2 cup (100g) granulated sugar
• 1/2 teaspoon salt
• zest of one lemon
• 1 teaspoon vanilla extract
• 1 cup (130g) all-purpose flour (I use organic all-purpose Spelt flour or organic King Arthur flour)
• 1 cup (130g) whole grain Kamut flour (I mill mine at home from whole grain berries, or you can buy pre-made Kamut flour)
• 4 tablespoons butter, cubed, room temperature
• 1 lb fresh plums about 4-5 plums, pitted and halved
• 2 tablespoons sugar

Equipment

9 x 13″ sheet pan (aka jelly roll pan, or quarter pan)
Stand mixer with paddle attachment
Non-stick parchment paper

Instructions

In a bowl of stand mixer, whisk together 1/2 cup (115g) sourdough starter and 1 cup (240g) kefir or buttermilk.

Add 1 egg, 1/2 cup (100g) sugar, 1/2 teaspoon salt, zest of 1 lemon and 1 teaspoon vanilla extract. Mix well. 

Add 2 cups (260g) sifted flour, and incorporate into the wet ingredients.

Connect the bowl to a stand mixer with a paddle attachment. 
With the mixer running, add butter, 1-2 pieces at a time. Scrape the bowl if needed, continue mixing until is batter is smooth.

Scrape the bowl if needed, continue mixing until batter is smooth. Cover and leave at warm room temperature for 6-8 hours.

Line 9×13″ baking pan with parchment paper. 
Cut each plum half into 5-6 pieces, and arrange in one layer on baking pan. 
Sprinkle 2 tablespoons sugar over the plums.

Drop spoonfuls of batter on top of plums, and spread evenly until all plums are covered. 

Leave at warm room temperature for 2 hours (until batter softens and rises some).
Preheat oven to 350ºF (180ºC). 
Bake plum pie for 30 minutes or until the top browns slightly. Turn pan once while baking. 

Cool the pie in the pan, then invert it onto a serving platter. 
Slice into 18 pieces.

NOTES

• Sometimes I use a mixture of whole grain Kamut and whole grain barley that I mill right before using it, with KoMo Mio Grain Mill. 
• I usually ferment doughs at 100ºF using a homemade fermentation chamber (cooler + heating pad). If your oven has a ‘bread proof’ function – that’s ideal! Fermentation does go a lot faster at that temperature, so keep an eye on the dough and not the recipe instructions. 
• If you are in a hurry, or your starter is weak, you can add 1/2-1 teaspoon of dry yeast with the wet ingredients. Don’t add more than that.
• This pie is not very sweet, feel free to increase sugar to 1 cup.