Hi Bridget, I was looking at this recipe and the math to convert it to incorporate a tangzhong starter, and I'm wondering how much additional liquid you're adding? By my reckoning it should be about 81g, so if you're adding more than that, this could be contributing to your issues. The kind of tunneling you describe sounds like it might be related to over-proofing, which can happen more rapidly with a wetter dough, particularly if the dough is very warm. This, in combination with your older yeast, might have led to a dough that didn't rise as high as expected, but also didn't maintain a good structure. You might want to experiment with reducing the added liquid a bit and also keep an eye on the dough temperature, and try to keep it in the ideal range of 75-78°F. One more factor that might be contributing is if you started using a different brand of unbleached all-purpose flour. Other brands of flour tend to be lower in protein than our flour, which means they won't develop as much gluten, but also won't absorb as much liquid. This could result in a weaker, wetter dough. Even if you're using our AP flour, you might want to try substituting our Bread flour when adding the tangzhong starter. We often recommend using Bread flour in our recipes that include a tangzhong starter and this should result in a stronger dough and a better rise. 

• Reply