Baking Yeast Raised Products n Yeast u Singlecelled

Baking: Yeast Raised Products n Yeast u Single-celled fungi u Enzyme zymase: t Produces CO 2 and alcohol t Uses sugar (glucose or fructose) as substrate u Four types for baking: t Active dry t Quick Rise t Instant t Cake

Baking: Yeast Raised Products n Yeast continued… u Temperature requirements t 105 -110°F or 41 -43°C for rehydration t Must not exceed 140°F (60°C) u Requires a food source to multiply u Proofing t A test for viability before baking t Mix with warm H 2 O and sugar t CO 2 should be released

Baking: Yeast-Raised Products n Flour u Different attributes depend upon: t Protein content t Gluten formation potential u Types: t Bread flour t Cake flour t All-purpose flour t Whole-wheat flour

Baking: Yeast-Raised Products n Flour continued… u Bread flour t Hard wheat t High gluten t Strong and elastic u Cake flour t Soft wheat t Low gluten t Smooth texture

Baking: Yeast-Raised Products n Flour continued… u All-purpose flour t Slightly weaker than bread flour t Multi-purpose u Whole-wheat flour t Contains gluten

Baking: Yeast-Raised Products n Other ingredients u Liquids t Water t Potato cooking water t Milk u Sugar t Facilitates yeast growth t Contributes to browning reaction

Baking: Yeast-Raised Products n Other ingredients continued… u Salt t Flavor enhancer t Allows gluten to stretch for a larger volume u Fat (optional) t Increases tenderness by shortening gluten t Aids in browning reaction t Decreases staling

Baking: Yeast-Raised Products n Preparation and Baking u Manipulation t Protein absorbs H 2 O t Gluten development occurs u Fermentation t CO 2 given off by yeast t Aeration of dough results t Volume doubles—fermentation is over

Baking: Yeast-Raised Products n Preparation and Baking continued… u Punching down t When size has doubled t Relieves stress on gluten strands t Squeezes out excess CO 2 u Proofing t Final rising t Takes less time than 1 st proof t More yeast than in 1 st proof

Baking: Yeast-Raised Products n Preparation and Baking continued… u Cooling t Let cool before cutting u Storage t Do not refrigerate! t Either freeze (long term) or keep at room temp.