Why did mine fail?
Pick the symptom. Each answer comes straight from the converter rule base — and filing testimony about your bake is what sharpens the next answer.
Gummy texture Fell apart / crumbly Dense / heavy Dry Sank in the middle Bland Spread too much Gritty
Dense / heavy
Weigh the flour. Published GF blend weights run 120–156 g per cup, so a careless cup can be 30% heavy. Rest batter 10–15 minutes so starches hydrate, and for gum-free muffins beat the batter until it visibly thickens — the opposite of the wheat rule.
Run your recipe through the converter — it applies these rules automatically.