While sugar and other sweeteners provide "food" for yeast, too much sugar can damage yeast, drawing liquid from the yeast and hampering its growth. Too much sugar also slows down gluten development. Add extra yeast to the recipe or find a similar recipe with less sugar. Sweet yeast doughs will take longer to rise.
Yeast feeds on sugar so by adding a tablespoon or two provides yeast a readily available food. This increases yeast's activity and speeds up fermentation as well. However, adding a large amount of sugar to your dough will affect yeast's metabolism. Sugar is hygroscopic which means it absorbs moisture from the dough.
Yeasts are fairly tolerant of high concentrations of sugar and grow well in solutions containing 40% sugar. At concentrations higher than this, only a certain group of yeasts – the osmophilic type – can survive.
Very high sugar content will effectively kill the yeast once a certain (high) alcohol content is reached. For these reasons, no wine is ever fermented completely "dry" (meaning without any residual sugar).
However, overloading the must with sugar can overwhelm the yeast and make it difficult for fermentation to begin. With small batches (1-gallon recipes), the amount of sugar is small enough that it won't bother the yeast.
A dough that has a high percentage of sugar (10% or more) will need more yeast than a bread made without sugar and will take a longer time to rise. A dough with more than 5% sugar (to flour weight) will brown on the surface earlier in the baking time than a dough with no added sugar or with less than 5%.
The increase in sugar concentration causes declines in yeast cell growth and size.
How does sugar affect bread dough? Sugar acts as a liquefier. It absorbs water, weakens the gluten structure, and makes the dough looser. The dough expands more when baking achieving an airier and softer crumb.
No matter what amount you choose, the rules hold. The ratio is 5:3.
Any loaf where the weight of the sugar is 10% or more of the flour weight* is going to rise sloooowly. Add too much sugar, and your bread will stop rising entirely.
If your dinner rolls aren't fluffy it could be because of one of two reasons. Either, you added too much flour or you possibly used all bread flour. Alternately, not giving your dinner rolls enough time to proof and get puffy before baking could yield dense rolls.
Water at 95°F is the fermentation temperature that yields the best result. Water at 140°F or higher is the kill zone for yeast. At temps like this or higher, you will have no viable live yeast left.
Too cold of water slows the growth of the yeast. Water should be added to yeast around body temperature: 98.6 degrees Fahrenheit.
If the yeast doesn't bubble, foam or react – it is dead. If the yeast is reacting very slowly or moderately, I would toss it and purchase new yeast. Using yeast that is partially expired will result in problem loaves.
All it takes is a small amount of dough enhancer per loaf to create a much lighter and fluffier result. Using a dough enhancer like Vital Wheat Gluten works to improve the texture and elasticity of the dough and elongate the strands of gluten. Doing so allows more room for the gas in the dough to develop and rise.
Yeast is too hot Yeast may have been dissolved in water that was too hot, or the liquid ingredients in the recipe may be too hot, causing the yeast to die. Yeast needs to be warm - not too hot, not too cold. Yeast is too cold If the other ingredients are too cold, it could cause some of the yeast to die.
If the area is too warm, bread will rise too fast and begin cooking before the yeast has finished acting. This will impart a "yeasty" taste to the dough that will be transferred to the finished baked loaf. Using old ingredients (rancid nuts, "old" shortening) will cause yeast breads to taste old or have an "off" taste.
The best treatment to get rid of most yeast infections comes down to medicated creams or a pill. Studies show that these creams and the oral pill, fluconazole, both work more than 90% of the time. Uncomplicated yeast infections usually respond to treatment within a couple of days.
“If the dough has risen too long, it's going to feel fragile and might even collapse as you poke it,” says Maggie. If this is the case, there's a chance you can save your dough by giving it a quick re-shape. Learn more about this fix in our blog on saving overproofed dough.
If the yeast does not foam after proofing, there could be a few reasons why. The most common is that the yeast has either expired or was not stored properly. If you're working with yeast that does not foam, you'll need to discard the yeast and buy a fresh batch before continuing the recipe.
The maximum amount of time dough can sit out on the counter is four hours for yeast-made bread, six for sourdough. Temperature, the characteristics of the sugars in the flour, the amount of yeast and the humidity of the room alter the length of the rise.
The general bread-making rule is 1% dried yeast to flour (ie 5g yeast for 500g flour). More than that and your bread will taste yeasty. You can use less if you want to, though - the dough will take longer to rise, but it will develop more flavour.
Glucose is the preferred substrate of yeast [1,41].
Too much yeast could cause the dough to go flat by releasing gas before the flour is ready to expand. If you let the dough rise too long, it will start having a yeast or beer smell and taste and ultimately deflate or rise poorly in the oven and have a light crust.