It's April 2020, just after Pesach, so there's no yeast or flour to be found in the grocery stores. Good excuse to start experimenting with sour dough!
Day 1: Soaked dates in water, put a lid loosely on top. I put them on a high shelf for a week (around 70-75F), taking off the lid and swirling the water around every day to make sure there was enough oxygen circulating.
Day 8: The date water smelled like soy sauce, definitely not like yeast. Hoping I wasn't going to grow a golem, I mixed a cup of date water with a cup of whole wheat flour. It bubbled a bit, which was encouraging. I covered it with a plate and left it on the same high shelf for 24 hours. I also added more water to the dates to see if I could get a second week's yeast from the same fruit (assuming I can find flour anywhere).
Day 9: The starter (left) was more bubbly and sticky, and definitely had not grown a golem. I added half a cup of warm water with two tablespoons of ground flax seed, two egg whites and one yolk (saving the other yolk for brushing the dough later), another cup of whole wheat flour, and 2 cups of matsah cake meal (center). Why matsah meal? Because I'm out of flour, and that's the next best option. I didn't add salt because I was afraid of killing any yeast that might be in there. It smelled basically like matsah. I brushed the dough with a spoonful of olive oil and left the bowl covered with a plate on a high shelf for another 24 hours (right).
Day 10: After 24 hours, it did not seem that the dough had risen at all, but it did have some air bubbles (left). I was glad I hadn't added any salt! I couldn't wait any longer, so I kneaded it and separated it into three sections, braided them, and put them in a glass baking tin to rise again (center, right). The dough had a great texture, really elastic and easy to work. I should note at this point that while I'm calling this challah (because it's a braided bread we were planning to eat Friday night with our shabbes meal), it's not halachically challah. I only used 4 cups of flour, so I didn't need to separate a piece (that's the actual challah) or say a blessing for separating.
Six hours later, the braided dough hadn't really risen at all, but it was time to bake it anyway! I brushed it with (too much) egg yoke and put it in the oven on 325F for an hour. I kept the temperature super low to encourage a longer baking time and more gradual rise.
The finished product is very dark and very dense. It smells like sourdough bread. It tastes like sourdough bread. I actually like it. Gut shabbes!