Hi Joanne, while switching to a different type of flour might cause temporary sluggishness, I don't think this should have caused your starter to stop bubbling and fermenting completely. If anything, whole wheat flour is likely to cause your starter to ferment a bit faster, so I'm wondering if something else might be going on with your starter. Are you seeing any bubbling and rising at all at this point? We consider lukewarm water to be 98°F to 110°F, which is actually a little warmer than you need to go with this process, so I would aim for the lower end of that range, or a bit cooler. The one thing that might actually kill your starter is excessive heat. Yeast will die at 140°F, so you don't want to get anywhere close to that in terms of water or environmental temperatures. 

If your starter is bubbling and rising a bit, it probably just needs a few days of twice a day feeding at room temperature to restore it to its normal activity level. Ideally you want your twice daily feedings to line up with when your starter is still ripe (at its peak rise, or just beginning to fall). Allowing the starter to fall significantly between feedings can lead to sluggish yeast behavior. If you've had your starter stored in a very warm environment (greater than 75°F) or if you've been feeding with very warm water, it's possible the starter began rising well, but gradually became sluggish as it repeatedly fell between feedings. If you think this might be happening, try feeding with room temperature water and keeping your starter at cool room temperature (68-70°F). You might also want to try offering your starter a "larger meal," which can be accomplished by reducing the percentage of starter relative to the water/flour you're feeding. For example, our regular sourdough starter routine calls for feeding 1:1:1 (starter:water:flour, by weight). A typical feeding looks like this: 1/2 cup (113g) starter + 1/2 cup (113g) water + 1 scant cup (113g) unbleached all-purpose flour. To offter your starter a larger meal you might want to try something more like 1:5:5 or 1:4:4. With our starter process, a 1:5:5 feeding would look like this: 23g starter + 113g water + 113g AP flour. The goal here is to help your twice a day feedings line up closer to the peak rise, which will keep your yeast more vigorous. 

For more help troubleshooting your starter, please don't hesitate to give our Baker's Hotline a call. We're generally here M-F from 9am-9pm EST, and Saturday and Sunday from 9am-5pm EST, and the number to call is 855-371-BAKE (2253). 

• Reply