amount of yeast,confusion

[frodo]

getting ready for my first sacrificial run..

I was reading in tried and true recipes. sweetfeed whiskey by Kentucky Skinner.

and another by Tater, Kentucky Skinner's recipe is a 6 gallon wash, and he calls for 5 packs of yeast
while Tater's is a 5 gallon wash,,only calling for 1 pack.

this is confusing this unworthy newbie,

will someone explain to me why the huge discrepancy between the 2 ?

edit,,,i read in this forum? 1 pk per gallon wash,,,{i think}

[bearriver]

Its a difference in preference. Both will work. However, pitch rates in the T&T are often carefully selected.

[InglisHill]

Get a real good starter going with a bit of diluted wash so it froths up, maybe a couple of litres worth and you are good to go, just chuck a bunch in. Using bread yeast I will use between 5tsp and 1/4 of a cup depending on how much yeast is in my yeast jar.

Just make sure that when you pitch they are of about the same temprature, the starter and the wash that is.

Don't sweat it too much Frodo.

[S-Cackalacky]

Some folks like to pitch a large amount to circumvent problems with other nasty microorganisms getting a foothold. Yeast will often dominate the wash environment over other microorganisms. The idea is to get a good population going quickly. If you practice good sanitation, a large yeast pitch might not be necessary.

[heartcut]

Pitching a lot of yeast makes it less likely that an infection of some unwanted microbes will get established. So does sanitation, of course.
Some recipes use low pitch rates for a certain flavor, but that's rare.
If you're using bread yeast from Sam's or Costco (really inexpensive), around 1/4 cup for 5 gallons works for me. If you're buying little packets of expensive yeast, do what InglisHill said, maybe even add a little sugar and yeast nutrient to the starter and let it work for a day before pitching.
Typing while Cackalacky was...

[frodo]

i picked up red star platinum yeast

http://redstaryeast.com/wp-content/uplo ... atinum.png" onclick="window.open(this.href);return false;" rel="nofollow

i must be over thinking

[Appalachia-Shiner]

I never use over a PACK or similar portion out of a pound of distillers yeast I bought. It always takes right off if the temperature is warm enough.
Can't imagine using 5 packs. Maybe in a hundred gallons or some such size.

[frodo]

here is the conversation.

Post subject: sweetfeed whiskyPostPosted: Tue Mar 23, 2010 5:39 pm
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If you like a really smooth whisky you need to try this recipe I have run it several times. It is easy and so far I have never had a ferment stall. If you try it let me know what you think. I have some that has aged on oak for about 2 months and it is really smoothing out. I oak at 55% ABV.


this is for 6 gallon wash

4" of sweet feed in the bottom of the bucket
7 pounds of white sugar
5 packets of bakers yeast or 8 tablespoons

heat 2 gallon of water to good hard boil then pour the water in the sweet feed add your sugar and stir for about 15min. the let stand for 90min. fill to 6 gallons with cool water after waiting 90min., your temp should be around 90F sprinkle your yeast in and stir gently. cover with lid and add your airlock. Mine is normally bubling away in about 4-6 hours. will run pretty good for about 2 days then will slow to a very slow rate. leave it for 5 days or untill you see it trying to clear sometimes it is 6 days. after that set it a cool place for about 24hours then rack it off and distill it. I normally get about 4 qaurts of low wines. sometimes my quart in the middle taste good enough I keep it aside and drink it just as it is.

after I run this through a pot still I use about half of my backset while it is still hot I put 7 pounds of sugar in the hot backset and convert my sugar. Let that cool to about 90F pour this back into your fermentor on your grain and yeast that was left in your bucket. add enough water to make 6 gallons normally my yeast wake up and are bubling away in about 4-5hours.

It seems very easy to me. I have really had good success with it. you can normally get your sweet feed at any farm supply store 50lbs for 7 bucks. It will last a long time

Mod edit to help with different size vessels:
Thanks Prairiepiss for the extra time on the calculations
So NIN posted that 4" in a 5 gal bucket is 7.69 lbs. It doesn't need to be exact. So let's break it down here.
You could go 1.5 to 1.75 lbs of sweetfeed and 1.5 to 1.75 lbs of sugar to a gallon of water. With no problems.
Or for the metric guys. .180 to .210 kg of sweetfeed and .180 to .210 kg sugar to 1 lt of water.
Or easier terms. Equal parts sweetfeed and sugar to end up with the SG you want.


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Tater
Post subject: Re: sweetfeed whiskyPostPosted: Tue Mar 23, 2010 10:03 pm
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Here is another one from parent site A "genuine" moonshine recipe, as still being used by Deb Brewer is ...

* 5 gallon bucket all grain horse feed (we use MannaPro Hi Grain sweet feed)
* one package of yeast (using bread yeast now--others will increase quality and ferment time)
* 5 pounds sugar
* water
Put enough feed to cover bottom of 5 gallon bucket a good 4 inches deep Add 5 pounds of sugar. Fill 1/2 full with warm water--warm enough to melt sugar but not so hot as to kill yeast. Mix until sugar is dissolved. Add yeast and mix some more finish filling with warm water--again not so hot to kill the yeast. Cover with lid--our lid has a little cap that screws on, leave it loose to breathe.

4-5 days later it's ready to run! This is an old-timer recipe and works quite well. Our liquor is always 170-190 proof. You can substitute corn meal for the grain (horse feed) but I don't recommend this for pot stills cuz you can't filter it well enough. The meal will settle and burn in the bottom of your still. The old-fashion way of making corn liquor--with real corn--just is not feasible time wise.

_________________
PLEASE READ THIS FORUMS RULES AND THESES Links: http://homedistiller.org" onclick="window.open(this.href);return false;" rel="nofollow and New Distiller Reading Lounge I use a pot still

[MitchyBourbon]

Frodo,

You have asked a good question. There is a big difference between five packs and one. So what's going on? If 1 pack of yeast will do the job why would anyone waste 4 more packs to do the same job? The answer lies in ester production. Most of the precursors for esters are created during the growth phase of fermentation. If you add enough yeast to begin with the growth phase is not necessary and can be skipped by not aerating the wash. By skipping the growth phase the precursors for ester production will be minimal.

[ranger_ric]

So Mitchy.
Are you saying that a small amount of yeast in a well aerated wash creates MORE precursors for esters than a large dump of yeast in a poorly aerated wash? Trying to understand too....??

[MitchyBourbon]

That's the idea.

[ranger_ric]

What about a big yeast dump in a well aerated wash??? Would that accomplish the goal.. or is it the oxygen in the wash?

[frodo]

will taste be effected by a higher dose of yeast?

[ranger_ric]

Frodo
The tastes are affected by esters... He is saying that a big dump of yeast in a low oxygenated wash cuts down on the precursors to the esters... I think that is what he is saying..

[skow69]

.

Most of the precursors for esters are created during the growth phase of fermentation.

I did not know that. That should be valuable information, but I get confused about esters. Aren't there any esters that we like? Just what is it that makes something an ester?

[MitchyBourbon]

Never tried a large a large over pitch of yeast accompanied with aeration. I would imagine you would still have a growth phase.

From what I've read and from experience over pitching and low/no aeration reduces the precursors that produce esters. So yes it has an effect on flavor.

If you do a Google on over pitching yeast you will find many topics that touch on this subject. Most are in regards to brewing beer but it is still relevant. A couple of years ago I came across an excellent article that was written regarding distillation that discussed over pitching and low aeration. I will see if I can find it again.

[MitchyBourbon]

.

Most of the precursors for esters are created during the growth phase of fermentation.

I did not know that. That should be valuable information, but I get confused about esters. Aren't there any esters that we like? Just what is it that makes something an ester?

hmmm... seems like a loaded question. I'm not a chemist, I did take a semester of organic chemistry on a dare.

Yes,
there are lots of esters we like especially those of us all grain fans. But not so much if your going for a neutral.

For us esters come from a carboxylic acid and an alcohol. That said there are various acids and various alcohols present in a given finished ferment not to mention various requirements for a given reaction.

[InglisHill]

Interesting, I also was unaware of this.

So makin a rum, you want the esters to produce........

Nice, I might change a few things in my next ferment and see if I can pick up some differences.

Thanks Mitchy.

[frodo]

thanks mitchy,,i have been schooled. i have more reading to do,,,i will google ester whiskey fermintation

[skow69]

.

Most of the precursors for esters are created during the growth phase of fermentation.

I did not know that. That should be valuable information, but I get confused about esters. Aren't there any esters that we like? Just what is it that makes something an ester?

hmmm... seems like a loaded question. I'm not a chemist, I did take a semester of organic chemistry on a dare.

Yes,
there are lots of esters we like especially those of us all grain fans. But not so much if your going for a neutral.

For us esters come from a carboxylic acid and an alcohol. That said there are various acids and various alcohols present in a given finished ferment not to mention various requirements for a given reaction.

It's a sincere question.

I have read the Wikipedia article several times. I have also taken the Khan Academy's intro Chemistry course recently. Trying to recover what I should have paid attention to in high school. Psych major, no hard science, even on a dare. So I gather it's the caboxylics and other various acids and various alcohols that are produced during the aerobic phase.

I will try overpitching without aerating and see how it goes.

[thecroweater]

Gee I wish i hadn't pre-hydrated that yeast 30 min before pitching was said by..... No one ever. Rehydrate the yeast before hand and you can get away with a lot less, if you have really cheap yeast well it don't matter much. as for aerated washes there is a pervasive believe that after the initial colonisation oxygen is no longer wanted or needed, t'is simply not true, The yeast may not need as much at once but continue to reproduce throughout the ferment and require some oxygen to continue and remain healthy. A stir every now and then during the ferment is not the taboo some will claim, although it will ferment without doing so it may not be optimum. i always end the ferment with a stir right to the yeast bed and see it re-kick more oft than not

[frodo]

http://whiskyscience.blogspot.com/2011/ ... vours.html

lite reading,,,,,,



Whisky Science
Bits of information about Scotch single malt whisky, its production, history and chemistry.

Wednesday, November 23, 2011
Fermentation flavours


Fermenting in Loch Lomond distillery
Whisky wort fermentation produces ethanol, but also a variety of important flavours. Yeasts produce higher (fusel) alcohols and organic acids, which together form esters. Additionally ketones, sulphur compounds and phenols are formed. Whisky fermentation is quite similar to beer fermentation, but there are couple of important differences; the wort is not boiled, the distiller's yeast is usually propagated aerobically and the fermentations are usually not aeriated or temperature controlled (except the starting temperature). Unboiled wort allows the enzymes to continue their work and break down the oligosaccharides to increase the alcohol yield, but it also enables contamination with bacteriae and wild yeasts. If the yeast used is propagated aerobically, it is faster to start the fermentation and contains more sterols and fatty acids and thus the wort needs less oxidation or rousing.

Yeasts use simple sugars for their growth and energy metabolism. Simplified; when the yeast has oxygen, it produces water and CO₂ from glucose, but in anaerobic conditions it turns glucose into ethanol and CO₂ or alternatively glycerol. To reproduce, the yeast needs fatty acids, sterols and amino acids for its membranes and the organelles inside the cell. Oxygen is often needed in the production of these building materials.

When yeast is pitched into the wort, it secures its energy reserves and if there are enough nutritients, it starts to reproduce by budding. The beefing up-phase is called the lag phase, and it is shorter if the yeast has been aerobically grown as the cells are usually full of nutritients already. The budding phase is called the log phase or the exponential phase, during which yeasts reproduce usually 3-4 times increasing the cell population about ten-fold. As the cells form new organelles and cell membranes, they produce a variety of different organic acids, fats and sterols including various intermediate products, some of which leak out of the cell into the wort. After that the nutritients and oxygen fall short and the cells do not reproduce, but try to produce sufficient energy to survive from the sugars, this is called the stationary phase. As the cells start to die or drop out from the fermentation, lactic acid bacteriae start to grow on the wort producing flavours typical of their metabolism, such as lactic acid and several lactones.

Yeast growth in whisky fermentation (Ramsay & Berry 1983)

The amount of higher alcohols depends on the yeast growth; basically the more the yeast grows, the more higher alcohols are formed. Therefore aeriation of the wort, high nitrogen, and high temperature promote fusel alcohol production. Ale strains usually produce more fusel alcohols than lager strains, partly because of the higher fermentation temperatures. Fusel alcohols themselves are not a desired flavour in the wort - producing usually a sharp, solventy notes - but together with acids they form esters, which are important and desired flavour compounds in whisky as they produce various fruity and flowery notes.
Amino acid Fusel alcohol
Leucine Isoamyl alcohol
Valine Isobutanol
Isoleucine Active amyl alcohol
Phenyl 2-phenylethanol
Tyrosine p-hydroxyphenylethanol / tyrosol
Tryptophan Tryptophol
Methionine Methionol
Table1. Aminoacids metabolise into different fusel alcohols


Ester formation depends on the amount of fusel alcohols and organic acids in the wort, but also on the activity of alcohol acetyltranferase enzymes (ATAase I and II), which in turn depends greatly on the yeast strain. Esters in the fermentation can be classified into two groups: The acetate esters (acetate+alcohol) and the ethyl esters (ethanol+fatty acid). The acetate esters are usually formed in greater amounts, but the ethyl esters can be very aromatic even in low concentrations. Common descriptors for the aromas of esters are listed in the table below. The short chain fatty acid esters (C6, C8) are formed early in the fermentation, the medium chain esters (C10,C12) quite evenly throughout the fermentation and the longer chain esters (C16) mostly at the cell-death phase. Increased cell growth usually results in lower levels of esters, due to lower levels of free fatty acids in the wort, as fats are used to build cell membranes. Organic acids are formed throughout the fermentation and at high levels they produce notes of vinegar, vomit and barnyard. The right proportion of fusel alcohols and free fatty acids or acetate is crucial when producing estery wort and avoiding the solventy off-notes from the excess alcohols and on the other hand the rancid aromas from the excess free fatty acids. An estery, fruity wort can be produced with warm long fermentations, high original gravities, high pitching rates with aerobically grown yeast and low nitrogen barley. Increased glucose levels tend to produce more short chain esters, for example isoamyl acetate with a typical banana aroma. High fermentation temperatures usually produce more acetate esters with mainly fruity aromas, but also medium-long chain ethyl esters, which can give an oily and waxy texture to the flavour.



Ester Name

• Ester Name

• Odor or occurrence

Odor or occurrence
Allyl hexanoate
pineapple
Benzyl acetate
pear, strawberry, jasmine
Bornyl acetate
pine
Butyl butyrate
pineapple
Ethyl acetate
nail polish remover, model paint, model airplane glue
Ethyl butyrate
banana, pineapple, strawberry
Ethyl hexanoate
pineapple, waxy-green banana
Ethyl cinnamate
cinnamon
Ethyl formate
lemon, rum, strawberry
Ethyl heptanoate
apricot, cherry, grape, raspberry
Ethyl isovalerate
apple
Ethyl lactate
butter, cream
Ethyl nonanoate
grape
Ethyl pentanoate
apple
Geranyl acetate
geranium
Geranyl butyrate
cherry
Geranyl pentanoate
apple
Isobutyl acetate
cherry, raspberry, strawberry
Isobutyl formate
raspberry
Isoamyl acetate
pear, banana (flavoring in Pear drops)
Isopropyl acetate
fruity
Linalyl acetate
lavender, sage
Linalyl butyrate
peach
Linalyl formate
apple, peach
Methyl acetate
glue
Methyl anthranilate
grape, jasmine
Methyl benzoate
fruity, ylang ylang, feijoa
Methyl butyrate (methyl butanoate)
pineapple, apple, strawberry
Methyl cinnamate
strawberry
Methyl pentanoate (methyl valerate)
flowery
Methyl phenylacetate
honey
Methyl salicylate (oil of wintergreen)
Modern root beer, wintergreen
Nonyl caprylate
orange
Octyl acetate
fruity-orange
Octyl butyrate
parsnip
Amyl acetate (pentyl acetate)
apple, banana
Pentyl butyrate (amyl butyrate)
apricot, pear, pineapple
Pentyl hexanoate (amyl caproate)
apple, pineapple
Pentyl pentanoate (amyl valerate)
apple
Propyl acetate
pear
Propyl hexanoate
blackberry, pineapple, cheese, wine
Propyl isobutyrate
rum
Terpenyl butyrate
cherry
Table2. Common esters and their aromas.
Diacetyl is an important flavour compound producing slick, buttery mouthfeel from concentrations of about 1ppm and at higher concentrations butterscotch or even cheesy flavours, and is usually considered as an off-note. It arises from the nitrogen metabolism during the exponential phase as the cells convert aminonoacids into ketones (such as diacetyl) and back to different aminoacids, but in the late stationary and the cell-death phases the cells use ketones in their metabolism as the sugars are running low. Brewers and distillers usually allow a diacetyl-rest period after the active fermentation to clear the wort of excess ketones. Too short fermentation time usually results in excess diacetyl. Heating, for example during distilling, increases the formation of diacetyl from other ketones. Diacetyl is quite volatile with a boiling point of 88⁰C and very hard to remove from the spirit even with column distillation.


Sulphur mining in an active volcano, Java (from zmescience.com)
Yeast metabolism produces many sulphur compounds, mostly sulphur dioxide (SO₂, burnt matches). SO₂ is easily reduced to hydrogen sulphide (H₂S, rotten eggs), which is very volatile and easily carried out of the wort if sufficient CO₂ is formed. Slow fermentations due to for example low temperature, low pitching rate, contamination or unhealthy yeast could fail to produce enough CO₂, which leads to high levels of H₂S in the wort. Some highly aromatic sulphur compounds such as dimethylsulphide (DMS) and -trisulphide (DMTS), dimethylsulphoxide (DMSO), S-methyl methionine (SMM), dithiapenthyls (DTPOH, DTPA) and various mercaptans originate mostly from the malt, but are metabolised by yeast and their concentrations can be either elevated or decreased during fermentation. Methione and cysteine are amino acids with a sulphur chain, which can be broken down during cell growth and energy metabolism. Starved cells can also turn into catabolic state (autophagosytosis), in which they break down their cell organnelles (and amino acids in the process) to produce energy, and this produces excess sulphur. This is probably why anaerobically grown brewer's yeast together with distiller's yeast produces more sulphur compounds than either one used alone. Starved brewer's yeast (cropped from the brewery, not from an aerobic propagation or a lab) produces over twice as much aromatic sulphur compounds than fresh yeast of the same strain. Distiller's yeast used alone produces slightly less aromatic sulphur than a common ale yeast, probably because of its better nutritional state. The aromatic sulphur compounds are not necessarily off-notes, but are in fact needed for full-bodied and complex aromas (in the right proportions, of course).

Phenols in whisky are mostly derived from peat burnt in the maltings, but some very flavour-active phenol compounds can be produced by yeasts. Wild yeasts produce significant amounts of 4-vinyl guaiacol, which has a very potent phenolic aroma. Phenolic note has been considered an off-note in brewing and therefore the brewers have usually chosen strains that do not have a functioning gene for 4-vinyl guaiacol-production, exceptions include most hefeweisen and rauchbier yeasts and of course the lambics brewed with wild yeasts. Apparently also the commercial distiller's yeasts are lacking the "phenolic off-flavour" genes.

The picture below sums the simple reactions involved in the flavour formation during alcoholic fermentation.

Flavour formation from alcoholic fermentations. (Ramsay 1982)

[MitchyBourbon]

Yes I said that yeast should always be rehydrated in plain water before pitching. Oxygen is not required for rehydrating. It is required if making a starter in which your intent is to grow more yeast with which to pitch. In this case if you wanted to limit adding oxygen and any precursors that may have been created in the starter. You could allow the starter to settle and decant the liquid off and just pitch the slurry.

[MitchyBourbon]

Nice find Frodo, very interesting read.

[InglisHill]

What would be interesting would be drawing up a chart with the boiling points of all those esters.......

I might get onto that.

[MitchyBourbon]

What would be interesting would be drawing up a chart with the boiling points of all those esters.......

I might get onto that.

Requirements for reaction as they pertain to distillation would also be interesting.

[shadylane]

I normally pitch a large amount of hydrated yeast.
My shine isn't going to be aged for years, so the esters produced by a long lag phase isn't wanted.
The large yeast population also finishes faster and decreases the odds of an off fermentation.

[rad14701]

Most here know me as being notorious for over-pitching yeast in my washes... I hate lag times and strive for the cleanest neutrals I can attain... Some precaution is required to eliminate the possibility of yeasty flavor or smell carrying over into the distilled spirits but once past that hurdle it becomes a non-issue... Yeast is cheap - don't skimp...!!!

[shadylane]

If you do a Google on over pitching yeast you will find many topics that touch on this subject. .

http://www.wyeastlab.com/com-pitch-rates.cfm" onclick="window.open(this.href);return false;" rel="nofollow
http://www.danstaryeast.com/about/frequ ... -questions" onclick="window.open(this.href);return false;" rel="nofollow

[1965 wite]

So is it bad to aerate everytime I sour mash sf or UJSSM? Could this be creating unwanted esters?