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Transcript of Yeast
d. Yeast is a micro-organisms classified in the kingdom Fungi! Close Up & Personal 349 different types of wild yeast
unicellular, although some species with yeast forms may become multicellular through the formation of a string of connected budding cells False Hypha all by myself...
don't want to be... (fakers) Asexual budding cells
Clones Reproduction How does yeast reproduce? Mommy... where do babies come from? Well honey...when a mommy and daddy love each other very much... A new organism grows on another one. The new organism remains attached as it grows, separating from the parent organism only when it is mature. Since the reproduction is asexual, the newly created organism is a clone and is genetically identical to the parent organism. What conditions are needed to activate yeast? Think back to the Meat Unit... ***Hint food-born pathogens (sugars) (ph balance of 5.6 to 5.4) (optimum temp is 37 f) Ringing any bells? ding ding ding??? Where do yeast live? Do they live in the... Suburbs? Downtown? Farm? Beach? Waterpark? JP? Saccharomyces Cervivisiae They live almost everywhere! Can yeast live here? Yes/No Yes/No dormant R.I.P death 0-10 C higher than 60 C Cold? Freezing? Extreme Heat? Favorite place to live... Bakers Yeast Dry Yeast Fresh Yeast Saccharomyces exiguus Wild Yeast on the outside of... Fruits Grains Yeast is granulated, forming tiny yeast particles, dried, and vacuum-sealed. While the yeast remains dormant in the package, through the appropriate methods, it can be activated. To activate dry yeast, desolve in
body temperature water. It is a soft solid, beige in color, and
is highly perishable. It is somewhat more tolerant of low temperatures than other forms of commercial yeast. To activate fresh yeast, add it to your recipe last. The steps to mixing a straight white dough using ... Dry Active Yeast 1. Dissolve yeast in water first.
2. Combine all ingredients in the bowl and mix.
3, Mix into a uniform dough. The steps to mixing a straight white dough using ... Fresh Yeast 1. Place flour and salt into mixing bowl.
2. Place fresh yeast on the opposite side of salt.
3. Add water.
4. Mix into a uniform dough. What roll does salt play in the dough? a. Salt slows down the yeast.
b. Salt acts as a preservative.
c. Salt is also a flavouring agent. (or kills it depending on how much you use). A yeast used for the leavening of sour dough bread How to start a starter... Day 1 Day 4 Day 10 What do yeast eat? Identify the carbohydrate a. bread flour
b. cake flour
c. pastry flour
d. rye flour Which is not a member of the
polysaccharides group? a. bread flour
b. cake flour
c. white sugar
d. rye flour Sugar! But where do they get sugar from??? Simple carbohydrate Complex carbohydrate sugar Hi! I am simple united we stand. flour Yeast consumes... a. simple carbohydrates
b. complex carbohydrates monosaccharides Polysaccharides We need to break them up! - glucose
- fructose simplest form of Complete the sentence . Complex carbohydrates are broken up by ___________ called ___________ and ______________ _______________. enzymes alpha beta amylase The Enzyme Trail Flour complex carbohydrate
polysacharide Alpha-amylase digest the amylopectin
attacks starch practically anywhere along its chains, producing smaller chains of various lengths. in flour A . Beta-amylase attacks amylose chains and breaks them into molecules of maltose. B . VVVVV maltose dextrin Beta-amylase digestion of starch results in a mixture of maltose and larger dextrin YEAST You are taking too long!
I will send some help! I am the enzyme... Maltase! Yeast produces the enzyme maltase to break maltose into glucose molecules that it can ferment glucose Fermentation!!! None of this happens without... Maltase What does hydration mean? The amount of water in a dough defines the type of bread it will make.
The difference in hydration changes the size of the hole structure and creates an open crumb. What does hydration have to do with bread? How it happens... Let us take a closer look Water is poured into the salt, flour and yeast mixture. YEAST A B M Maltase breaks down maltose
into glucose Yeast consumes glucose
begins fermentation Beta Amylase breaks the chains down into maltose Complex carbohydrate Alpha Amylase breaks the complex carbohydrate chains down at random. P Proteins begin to absorb water True / False To make a loaf of bread all you have to do is add water to flour, yeast and salt then bake it. Mixing the dough helps develope the gluten. True / False Gluten is a protein found in wheat flour. True / False Alveograph - Measures strength and elasticity through the resistance of the dough to expand into a bubble
Extensigraph - Measures dough extensibility and resistance to extension
Falling Number - Measures the effects of sprout damage
Farinograph - Measures water absorption and dough strength
Flour Color Analysis - Standardized test to measure flour color
Glutomatic - Measures wet gluten content of the flour
Mixograph - Measures water absorption and dough mixing characteristics
Rapid Visco Analyzer - Measures starch properties of flour
Solvent Retention Capacity (SRC) Cake Flour Bread Flour Whole Wheat Light/ Dark Rye Pumpernickle There are four major types of gluten these are
Glutenin and Gliadin = both are gluten forming
Globulin and Albumin= are both non gluten forming The protein content in the flour is measuring the amount of potential gluten. The darker the flour the more protein. High gas production.
Higher content in rye, pumpernickle and whole wheat flour. The type of gluten = the mixing method
1. Scaling out (or weighing out) ingredients.
2. Choosing the right ingredients.
3. Calculating the dough temperature/ mixing
4. Stages of fermentation
5. Resting and punching down
6. Slashing and baking Steps To A Good Loaf Of Bread
If a yeast dough is either too warm or too cold major deficiencies will be evident in the final baked product.
The temperature of the water directly relates to the speed of fermentation.
The Optimum temperature being 80F or 26C. Here is the formula to calculate the dough temperature. Key Points: Dough Temperature Desired Dough Temperature
(DDT) x 3 = A
- Flour Temperature
- Room Temperature
- Friction Factor
= Water Temperature take this amount and
minus the temperature of the
flour, room and friction Now we know what temperature
the water must be
80 x 3 = 240
Minus Flour Temp - 60
Minus Room Temp - 84
Minus Friction - 28
Water temperature required 68F Example: Desired Dough Temperature of 80 F Mixing
It is one of the major factors defining the crumb (structure) of the loaf.
If a dough is mixed for just a short time on low speed then the dough will not develop the gluten therefore producing a small and dense loaf.
If mixed too long then the gluten strands will become over worked and tear leaving you with... you guessed it... another crappy loaf.
Window test is way to check your dough to see if you have developed the right gluten structure. Window Test Pinch off a small piece of the dough and slowly stretch it out until paper thin.
If it tears easily or looks like a thick thick spider web then your dough is not ready.
If it has a smooth baby bum texture then chances are you have developed the right amount of gluten. Fermentation I am hungry!
Resting the dough is very important as it gives the enzyme Protease a chance to cleave the peptide (protein) bonds.
Proteases are involved in digesting long protein chains into short fragments. Remember that gluten is a protein.
This enzyme is making your dough relax enough so that when you shape it you actually are tightening and improving your gluten strands. Make sense?
Punching down means that you are knocking out all of the gasses trapped inside the gluten strands and again tightening and improving the crumb of your final product. Resting and Punching Down Slashing your dough moments before it is placed in the oven serves two purposes.
1. To make the loaf or bun ascetically pleasing.
2. To control the final conversion of sugars into carbon dioxide. When your dough is first placed into the oven two things happen.
1. The Maillard Reaction occurs. Simply put, your crust of your bread sets first.
2. The yeast has its final who-ra because the oven temperature has increase the temperature of the dough. (Remember that the warmer the temperature the faster the yeast converts the starches and sugars into CO2 and alcohol)
So the yeast thinks to him self “oh, yeah! its hot in here, my time to shine” and gives the dough its final rise until it reaches 60C. At that point the yeast die.