AbstractBackground and objectivesBaking tests must be performed with formulations giving controlled gas production. The aim of this study was to investigate the effect of sucrose and water on yeast gassing power in dough. Total gas production, gas production rate, and residual fermentable sugars were determined in dough made with white flour and ten wholemeal samples.FindingsWith white flour adjusted for diastatic activity, gas produced after 3 hr at 38°C was constant in dough containing up to 6% sucrose. In the latter, yeast gassing power increased according to water content contrary to non‐sugared dough which gave uniform gas production. Yeast inhibition was seen with all flour samples tested. Gas production in dough also varied according to the yeast lot.ConclusionsSucrose and lack of water inhibited yeast gassing power in dough. Depending on the water content, fermented dough with 6% sucrose produced 10%–30% less gas than non‐sugared dough.Significance and noveltyYeast was inhibited by osmotic pressure in dough containing too much sugar and, to a lesser extent, too little water, resulting in variable gas production and potential bias in bread volume. Baking tests on flour with low water absorption should be performed with non‐sugared dough.