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Yeast and StartersYeast and StartersYeastYeast

• Yeast is found everywhere in nature• 500 different kinds• Baker’s yeast is one species:

Saccharomyces cerevisiae• Yeast is a living organism• It is unicellular• Yeast has the ability to ferment carbohydrates

once they are simple sugars

FermentationFermentation

Definition:

The chemical processin which the enzymesnaturally present inyeast convert sugars toa gas and alcohol

YeastYeast

Yeast is living andtherefore requiresseveral things in orderto perform properly:

• Moisture• Food• Temperature• Correct pH• Time• Structure

Functions of YeastFunctions of Yeast

• Leavening• Maturing the dough• Flavor• Aroma

Types of YeastTypes of Yeast

Compressed• 70% moisture• 2-3 weeks in fridge• 3-4 mths in freezer• Dissolve in 80F-90F

water

1& 1/2 tsp.

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Types of YeastTypes of Yeast

Active Dry• 8% moisture• 1 pkg = 2 1/4 tsp =

1/4oz• Dissolve in 105F-

110F water

Types of YeastTypes of Yeast

• Instant (SAF red label)• Used at 1/3rd less

compressed• Used at 1/4 less than

active dry• 1 pkg. Active = SAF 2 1/4tsp = 1 1/2 tsp.• Can be blended with

flour directly• Or added to the dough

after 30-60 seconds ofmix time

Straight Dough MethodStraight Dough Method

VERY SIMPLE. . .Put everything in the bowl

and mix!Know your type of yeast first:

compressed and active dryyeast can be dissolved inthe water

SAF or instant yeast must bedry mixed or sprinkled onformed dough

Don’t add all the flour in therecipe. Hold back somefor kneading.

Starters & Longer FermentationsStarters & Longer Fermentations

Definition

• Any sourdough,sponge or yeastedpiece of dough that isincorporated into anewly mixed breaddough to boostfermentation

StartersStarters

• Sponge starter• Most basic: All the liquid in a recipe, enough flour to

make a pancake like batter• For a quick rise, add all the yeast to the liquid and flour.• For a longer rise, add 1/3rd of the yeast amount• NO SALT, NO FAT• Let rise till active and bubbly, then add rest of

ingredients• The less yeast you use and the longer you let it rise the

more flavorful the resulting bread

PoolishPoolish

Type of sponge methodusing less yeast

French-style pre-ferment Much wetter < 1% commercial yeast For 2# dough 1/4tsp.

Yeast• Why? Improved flavor,

texture, shelf life, moreflexibility to risingschedules

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PoolishPoolish

• Soupy texture• Like pancake batter• Usually equal parts flour

and water

FORMULA2 1/2 cups br. Flour1 1/2 cups water, r.t.1/4 tsp. instant yeast

BigaBiga

• Firm starter• My favorite biga:

• 6 oz flour + 4 oz water• 1/8 tsp. Yeast• Let sit 12 hours or

overnight• OR

• 2 1/2 cup bread flour• 1/2 tsp. instant yeast• 3/4 cup water + 2 TB.

Biga + Poolish Side by SideBiga + Poolish Side by Side

BIGA2 1/2 cup bread flour3/4 cup water + 2 TB.

1/2 tsp. instant yeast

POOLISH2 1/2 cups bread flour1 1/2 cups water, r.t.1/4 tsp. instant yeast

Pre-fermentPre-ferment

• A piece of fermenteddough left over from aprevious batch

• This starter is added toa new batch of doughto give more depth offlavor

Sourdough StarterSourdough Starter

• Natural leavening of wild yeast(Saccharomyces exigus) and bacteria(Lactobacillus san francisco) captured in amixture of flour and water

• Several starters can be used to capture thesewild yeasts: rye flour, honey, organicgrapes, cumin

• It takes 10-14 days to build and then use anew sourdough starter

Sourdough StarterSourdough Starter

• Saccharomyces exigus does not ferment maltosebut ferments the other carbohydrates present inflour - glucose, fructose, glucofructosans

• It also thrives in an acidic environment• Lactobacillus san francisco does ferment maltose

and produces acids that characteristically flavorthe bread

• Sourdough takes at least three days to makeincluding building the starter

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Sourdough StarterSourdough Starter

1 2

3 4

Sour Dough ProjectSour Dough Project

You need to keepYou need to keepa daily diarya daily diary(legible).(legible).

Sour Dough ProjectSour Dough Project

You will beYou will besuppliedsuppliedpineapple juice,pineapple juice,diastatic diastatic maltmaltpowder, and flourpowder, and flour

Sour Dough ProjectSour Dough Project

You will need toYou will need tosupply your ownsupply your ownspring water (orspring water (orfiltered water).filtered water).

Sour Dough ProjectSour Dough Project

You need to keep aYou need to keep adaily diary (legible) ofdaily diary (legible) ofwhat you didwhat you did(refreshments and(refreshments andtimes) and how yourtimes) and how yourstarter looks, acts,starter looks, acts,and smells.and smells.

Sour Dough ProjectSour Dough Project

Day 1 - 2:Day 1 - 2:

Mix pineapple juice,Mix pineapple juice,

Wheat flour and maltWheat flour and maltpowder. Stir 2-3powder. Stir 2-3times a day. It istimes a day. It isimportant to addimportant to addoxygen to theoxygen to themixture.mixture.

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Sour Dough ProjectSour Dough Project

Day 3-4:Day 3-4: Fermentation, Fermentation,add new refreshmentsadd new refreshments

Day 4 or 5:Day 4 or 5: Refreshing Refreshingthe culture add waterthe culture add waterand flourand flour

Day 5 or later:Day 5 or later: Discard Discard1/2 the sponge and1/2 the sponge andadd more water andadd more water andflour. Fermentationflour. Fermentationshould be happeningshould be happening

Mother sponge:Mother sponge:Building the starter.Building the starter.Mix 2/3 cup of theMix 2/3 cup of theseed culture from dayseed culture from day5 or later with 1 cup5 or later with 1 cupwater and 2 1/3 cupswater and 2 1/3 cupsflour. It should rise atflour. It should rise atleast 1 1/2 - 2 timesleast 1 1/2 - 2 timesits volume in 4 - 8its volume in 4 - 8hours. Refrigeratehours. Refrigerateovernight.overnight.

Sour Dough ProjectSour Dough Project

Your mother sponge is now ready to be the starterYour mother sponge is now ready to be the starterfor your bread.for your bread.

Feeding: Your sourdough will need to beFeeding: Your sourdough will need to berefreshed every so often 100 % flour: 75% water:refreshed every so often 100 % flour: 75% water:33.3% starter (3 oz flour: 2 1/4 oz filtered water33.3% starter (3 oz flour: 2 1/4 oz filtered water:1 oz starter). If you leave it more than 2 weeks:1 oz starter). If you leave it more than 2 weeksyou will need more than 8 hours to revitalize ityou will need more than 8 hours to revitalize itand you might need to refresh it a couple ofand you might need to refresh it a couple oftimes with more flour and water.times with more flour and water.

Sour Dough ProjectSour Dough Project

The project is dueThe project is dueJuly 6.July 6.

This means youThis means youwill turn in a diarywill turn in a diaryand actually bringand actually bringin the starter (noin the starter (nomatter what shapematter what shapeits in)!its in)!