Yeast Starter

[grandadrob]

Guys, why are you making starters with dry yeast?
To ensure that the yeast is viable before adding it - I had a dead sachet once......

 

[MHB]

Lets pin down some basic terms, helps if everyone is on the same page.

Proofing - Putting yeast in tepid water for long enough for it to show signs of activity "proving" that the yeast is alive. Probably not really necessary these days as the yeast is likely to be better condition before its chucked into water at a usually unmeasured temperature. Which is odds on to be doing more harm than good.

Rehydrating - Putting yeast into water (ideally with some minerals) at the optimum temperature (usually in the low 30's C - very strain dependent and specific) and allowing the yeast to fully hydrate so it is ready to start fermenting when its added to the wort. During WW2 a new way to dry yeast was developed, what was called Active Dry Yeast, it was much more stable than older dry yeasts but not infallible. Rehydrating both proofs the yeast and prepares it for use. The most recent development is a form of "Instant" yeast it is ready to be added directly to the wort, this is the type of yeast Lesaffre refers to under its E2U banner. Most dry brewing yeast is now this type of yeast.
You can rehydrate it but unless care is taken again its easy to do more harm than good. Slight variations from a fairly narrow temperature, mineral and pH range can kill off a fair fraction of the yeast, especially Lager yeast.
If you want to rehydrate do it properly, follow the makers instructions precisely. It is generally recommended that yeast not be hydrated and not pitched into the wort for more than half an hour, sitting around too long and it will be trying to reproduce without the nutrients in the wort being available the yeast will start using up its internal reserves and wont be as healthy when you do get around to pitching.

Starter - Rehydrating yeast in a nutrient media (usually wort) and with available oxygen will help the yeast reproduce increasing the population. If all the required nutrients most of the yeast will get on with making yeast, after a lag phase where the yeast attemperates to its new environment (around 1-3 hours or so) and given all the required nutrients, in theory yeast can reproduce every 20 minutes. In the real world its closer to 2 hours per generation. Until the yeast runs out of any of its many required nutrients (in a brew its usually Oxygen) or until it reaches a certain population limit usually in the 200-300million cells / mL range.
It would be a big mistake to think you are going to get "optimum" rates of population growth at home. Braukaiser gives a very practical way to get a reasonable idea of how much yeast you end up with.
A starter is usually cooled allowing the yeast to settle, the liquor above the yeast being discarded, the new larger population being used to inoculate the wort.

Active Starter - A portion of the wort to be fermenter (or fair approximation) is inoculated, kept well aerated and at a time when the yeast is still actively reproducing at the same temperature that the main wort is to be fermented, introduced to rest of the wort.
The amount of extra yeast is less than can be made in a starter, but the yeast tends to hit the ground running and in very good condition. Works best for lagers being fermented reasonably cool.
Can be a follow on from making a starter (settle the yeast, decant liquor, add fresh wort, aerate use when fermenting well) or when the initial population isn't too small but more is required. It will speed up the ferment.

Having had a dead yeast packet (once) 20 years ago I wouldn't regard as a good enough reason to muck around with yeast. I would normally say adding Ascorbic Acid to a starter would be a pretty weird notion, mind you it might be all that's saving you from serial infections, keeping a 500g brick of yeast in the fridge is pretty hairy.
The odds of infection approach a certainty. Adding acid to a starter is far from best practice but it might be suppressing some of the inevitable bugs. Not something I would recommend.
Mark

 

[grandadrob]

Mark great post. The wort is acidic and adding dry yeast to it is fine. Therefore adding yeast to an acidic nutrient rich 200 ml bottled water starter in a clingfilmed 500 ml jar is fine, surely. So far I have not mentioned that I get a 1 to 2 inch head on the starter in 60 to 90 minutes, then I pitch. I have been doing this for more than 10 years. The 500 gm pack of normal dry yeast spherules is a new technique for me, I am 7 months into this technique and still have 300 gm in the pack, It is only open for 10 to 15 seconds, I squeeze the air out, fold it down, selotape it and straight back into the fridge.

7:40 am here, freezing fog, minus 4.2 deg C and my water is heating up. Today it is a medium to dark bitter loaded with cascade hops. And now for breakfast.....

 

[BrewLizard]

I don't see the appeal of 500 g yeast packets for the home gamer. As per Fermentis' own advice states, you get a week after opening if you flush the air out.

Of course, it will probably continue to brew good beer at near full strength for months to come, but how many? Viability will drop off to the point of needing more and more yeast. Eventually, you'll need to use twice as much, and given the 500 g packets are about half the price per gram, you're behind as soon as this starts happening.

The problem is you have no way of knowing how much extra you need to compensate.

And this all assumes you're properly flushing the yeast of air, not just sellotaping it.

It also assumes your fingers or spoon or the air you expose it to in opening the packet ~50 times doesn't introduce significant humid air or bacteria at any point.

Do it all perfectly and you save 50% on yeast costs?

Versus...harvesting yeast (saves 50% the first time, then 33%, then 25% and eventually approaches free), or overbuilding starters, which costs the same + $1 of DME per brew.

 

[grandadrob]

I observe my starter, and I observe the fermentation progress. So far no observable difference / problems. I am pitching 15 gm yeast to 22 litres of wort. So I am not saving money but slight overpitching works for my brews normally 3.6% to 4.1 %. At kitchen temperature in a skinflints house at this time of year, they take 5 to 6 days to ferment out, when I bottle in a range of sizes from 250 ml to 2 litres. It is minus 2 C in my garage where todays mash is about 35 minutes in.......

 

[MHB]

What makes you think yeast likes an acid environment.
Yes fermentation will acidify the brew from 5.1-2pH at the end of the boil down to around 4.1*4.4pH by the end of fermentation.
Yeast also makes Alcohol and CO2, enough of either of these will stop the ferment, in fact they will poison the yeast.
Sorry I don't agree that acidifying the starter is a good idea. We are lucky yeast is such a tolerant organism but that's not an excuse to put it under un-necessary pressure, especially just because it feels like a good idea.
Mark

 

[grandadrob]

I am not a scientist. I read somewhere that yeasts like slightly acid conditions. And an expert on sourdough said on youtube that he gets better starters when he adds a little vitamin C to his organic flour bottled water "starter starter".......think about it.

 

[grandadrob]

Preparing Dry Yeast (copied from John Palmer How to Brew)

Dry yeast should be re-hydrated in water before pitching. Often the concentration of sugars in wort is high enough that the yeast can not draw enough water across the cell membranes to restart their metabolism. For best results, re-hydrate 2 packets of dry yeast in warm water (95-105°F) and then proof the yeast by adding some sugar to see if they are still alive after de-hydration and storage.



If it's not showing signs of life (churning, foaming) after a half hour, your yeast may be too old or dead. Unfortunately, this can be a common problem with dry yeast packets, especially if they are the non-name brand packets taped to the top of malt extract beer kits. Using name brand brewers yeasts like those mentioned previously usually prevents this problem. Have a third packet available as back-up.



Re-hydrating Dry Yeast
1. Put 1 cup of warm (95-105F, 35-40C) boiled water into a sanitized jar and stir in the yeast. Cover with Saran Wrap and wait 15 minutes.
2. "Proof" the yeast by adding one teaspoon of extract or sugar that has been boiled in a small amount of water. Allow the sugar solution to cool before adding it to the jar.
3. Cover and place in a warm area out of direct sunlight.
4. After 30 minutes or so the yeast should be visibly churning and/or foaming, and is ready to pitch.

Note: Lallemand/Danstar does not recommend proofing after rehydration of their yeast because they have optimized their yeast's nutrional reserves for quick starting in the main wort. Proofing expends some of those reserves.



I add brewing sugar with my vitamin C and nutrient to bottles water and add the dried yeast. Today’s “starter” took 2 hours to develop a one inch head.



The vitamin C may not help, but it surely can do no harm.

 

[kadmium]

Preparing Dry Yeast (copied from John Palmer How to Brew)

Dry yeast should be re-hydrated in water before pitching. Often the concentration of sugars in wort is high enough that the yeast can not draw enough water across the cell membranes to restart their metabolism. For best results, re-hydrate 2 packets of dry yeast in warm water (95-105°F) and then proof the yeast by adding some sugar to see if they are still alive after de-hydration and storage.



If it's not showing signs of life (churning, foaming) after a half hour, your yeast may be too old or dead. Unfortunately, this can be a common problem with dry yeast packets, especially if they are the non-name brand packets taped to the top of malt extract beer kits. Using name brand brewers yeasts like those mentioned previously usually prevents this problem. Have a third packet available as back-up.



Re-hydrating Dry Yeast
1. Put 1 cup of warm (95-105F, 35-40C) boiled water into a sanitized jar and stir in the yeast. Cover with Saran Wrap and wait 15 minutes.
2. "Proof" the yeast by adding one teaspoon of extract or sugar that has been boiled in a small amount of water. Allow the sugar solution to cool before adding it to the jar.
3. Cover and place in a warm area out of direct sunlight.
4. After 30 minutes or so the yeast should be visibly churning and/or foaming, and is ready to pitch.

Note: Lallemand/Danstar does not recommend proofing after rehydration of their yeast because they have optimized their yeast's nutrional reserves for quick starting in the main wort. Proofing expends some of those reserves.



I add brewing sugar with my vitamin C and nutrient to bottles water and add the dried yeast. Today’s “starter” took 2 hours to develop a one inch head.



The vitamin C may not help, but it surely can do no harm.

Vitamin C is an antioxidant so it will be scavenging up free oxygen in the water which is counter productive to yeast growth.

I believe you will also find the vitamin C used in baking is because it breaks down the glucan in the flour to elasticise it more. I once saw a bloke add a little diesel to his engine oil when flushing, I wonder if that would help me flush my kegs better. Surely if it worked for that, logic states it must be good for flushing things out.

If you decide to go against what the yeast manufacturers state to do, that's up to you. But even JP states that Llalemand and Fermentis do not recommend hydrating yeast.

The only time I rehydrate yeast is when making mead, and that's using something like D47 wine yeast and I use Fermaid Protect hydrating powders and then do TOSNA nutrient additions.

If you want to make fluffier bread add Vitamin C, if you want to make stressed, unhappy and oxygen deprived yeast add vitamin c.

 

[Grmblz]

@grandadrob OK, so you have a book, written by:
John J. Palmer is the author of the self-published book, How to Brew and an active member of the homebrewing community. Palmer began writing How to Brew in 1995. The website The Real Beer Page hosted the first edition of the book at howtobrew.com. Palmer self-published a print edition of How to Brew in 2000.

So, 25yrs ago an enthusiastic homebrewer published his own book (it has recently been revised and for what it is, it's a great general reference for people just starting the hobby)
He recommends rehydrating yeast in a cup of water, the people that make the stuff say 10 times its weight, for an 11.5gm packet that's 115ml, under half a cup.

On the other hand you have this from the manufacturers, specialising in just one aspect/ingredient of brewing, and published within the last two years

From Lallemand:
YEAST REHYDRATION PROCESS Step by Step - Sanitize the upper part of the pack (e.g. ethanol 70%) and the scissors before opening. - Sprinkle the yeast on the surface of 10 times its weight in clean, sterilized water at 30-35°C (86- 95F). - Leave it undisturbed for 15 minutes, stir gently to suspend yeast completely. - Leave it for 5 more minutes at 30-35°C (86- 95F). - Attemperate in steps at 5-minute intervals of 10°C to the temperature of the wort by mixing aliquots of wort in order to adjust the temperature of the hydrated yeast, with no delay. Please Do Not - Do not use distilled or reverse osmosis water, as it will result in loss of viability. - Do not stir right after sprinkling, as it may break the yeast cell membrane. - Do not allow attemperation to be carried out by natural heat loss. This will take too long and could result in loss of viability or vitality

From Lessafre (Fermentis):
Direct pitch If the brewery is not equipped with a system designed for the rehydration step, we highly recommend a direct pitch. To do so we recommend using the necessary quantity in weight of ADY and to put it into the fermentation vessel during the first part of the wort cooling step. The temperature of cooling will be the same as the temperature used to start fermentation. There is no need for aeration during this process.

IF YOU ARE USED TO REHYDRATE DRY YEAST, NO WORRY you still can! Just follow our recommendation process. -
Rehydrate the dry yeast into yeast cream by sprinkling it on 10 times its own weight of sterile water or hopped wort. - The temperature of the hydration media is between 10 and 28°C (50-82,4°F); and should ideally be close to fermentation temperature. - Leave to rest; and optionally agitate gently (no violent agitation) for about 15 minutes. - Finally, pitch the resultant cream into the fermentation vessel.
AFTER REHYDRATION, BACTERIAL CONTAMINATION CAN DEVELOP IN THE SLURRY. For that reason, we recommend a rehydration in sterile hopped wort compared to sterile unhopped wort or sterile water. The iso-alpha acids (ideally above 5ppm, the equivalent of 5 IBU) present in the media will protect it from Gram + bacterial development and will not affect the rehydration process of the ADY.

Look at my post in this thread #54 for links to the above.

You will note they are very specific about what to do, and even go to the trouble to explain why, they do NOT use the same process, their recommended temp's are different, as is their production method.

What is being discussed here is merely "best practice" for what we have currently available to make craft brews, there are many different ways to end up with an alcoholic beverage, and you are free to use whatever method you choose, but this forum is about advancing the craft, and improving brewers knowledge, no one knows everything, and we all need advice at times, you can either take that advice offered, or ignore it, your choice.

 

[grandadrob]

Kadmium - I agree to disagree with you - lol - the manufacturer is not always 100 % truthful - I am just coming from years of doing something that works for me - tell you what - fly over here when it is safe to do so and I let you taste my beer - eg tonights beer was brewed just 3 weeks ago and it is nectar - is that a word u understand - if not it it is extremely nice old chap. Or possibly chappess. We have to be poltically correct, non sexist etc..................

 

[BrewLizard]

Your beer tasting good is not even close to counting as evidence of vitamin C helping your starter.

 

[kadmium]

Kadmium - I agree to disagree with you - lol - the manufacturer is not always 100 % truthful - I am just coming from years of doing something that works for me - tell you what - fly over here when it is safe to do so and I let you taste my beer - eg tonights beer was brewed just 3 weeks ago and it is nectar - is that a word u understand - if not it it is extremely nice old chap. Or possibly chappess. We have to be poltically correct, non sexist etc..................

What makes you think I have such a tenuous grasp on the English lexicon as to be unable to discern the use of the word nectar in relation to the description of a beer. Did you assume I would think you had literally produced a transmutation of wort into the sugary secretion of a flower?

Alas, fear not for I had the insight to discern the true context of the word nectar as it was juxtaposed with other positively descriptive words, to which I assumed you were referring to the colloquial "nectar of the gods"

Do you understand the above? TLDR stop assuming that I can't spell nor understand your below average vocabulary. I have seen the extent of your mental flexibility and it leaves one wanting.

 

[Coalminer]

@grandadrob OK, so you have a book, written by:
John J. Palmer is the author of the self-published book, How to Brew and an active member of the homebrewing community. Palmer began writing How to Brew in 1995. The website The Real Beer Page hosted the first edition of the book at howtobrew.com. Palmer self-published a print edition of How to Brew in 2000.

So, 25yrs ago an enthusiastic homebrewer published his own book (it has recently been revised and for what it is, it's a great general reference for people just starting the hobby)
He recommends rehydrating yeast in a cup of water, the people that make the stuff say 10 times its weight, for an 11.5gm packet that's 115ml, under half a cup.

On the other hand you have this from the manufacturers, specialising in just one aspect/ingredient of brewing, and published within the last two years

From Lallemand:
YEAST REHYDRATION PROCESS Step by Step - Sanitize the upper part of the pack (e.g. ethanol 70%) and the scissors before opening. - Sprinkle the yeast on the surface of 10 times its weight in clean, sterilized water at 30-35°C (86- 95F). - Leave it undisturbed for 15 minutes, stir gently to suspend yeast completely. - Leave it for 5 more minutes at 30-35°C (86- 95F). - Attemperate in steps at 5-minute intervals of 10°C to the temperature of the wort by mixing aliquots of wort in order to adjust the temperature of the hydrated yeast, with no delay. Please Do Not - Do not use distilled or reverse osmosis water, as it will result in loss of viability. - Do not stir right after sprinkling, as it may break the yeast cell membrane. - Do not allow attemperation to be carried out by natural heat loss. This will take too long and could result in loss of viability or vitality

From Lessafre (Fermentis):
Direct pitch If the brewery is not equipped with a system designed for the rehydration step, we highly recommend a direct pitch. To do so we recommend using the necessary quantity in weight of ADY and to put it into the fermentation vessel during the first part of the wort cooling step. The temperature of cooling will be the same as the temperature used to start fermentation. There is no need for aeration during this process.

IF YOU ARE USED TO REHYDRATE DRY YEAST, NO WORRY you still can! Just follow our recommendation process. -
Rehydrate the dry yeast into yeast cream by sprinkling it on 10 times its own weight of sterile water or hopped wort. - The temperature of the hydration media is between 10 and 28°C (50-82,4°F); and should ideally be close to fermentation temperature. - Leave to rest; and optionally agitate gently (no violent agitation) for about 15 minutes. - Finally, pitch the resultant cream into the fermentation vessel.
AFTER REHYDRATION, BACTERIAL CONTAMINATION CAN DEVELOP IN THE SLURRY. For that reason, we recommend a rehydration in sterile hopped wort compared to sterile unhopped wort or sterile water. The iso-alpha acids (ideally above 5ppm, the equivalent of 5 IBU) present in the media will protect it from Gram + bacterial development and will not affect the rehydration process of the ADY.

Look at my post in this thread #54 for links to the above.

You will note they are very specific about what to do, and even go to the trouble to explain why, they do NOT use the same process, their recommended temp's are different, as is their production method.

What is being discussed here is merely "best practice" for what we have currently available to make craft brews, there are many different ways to end up with an alcoholic beverage, and you are free to use whatever method you choose, but this forum is about advancing the craft, and improving brewers knowledge, no one knows everything, and we all need advice at times, you can either take that advice offered, or ignore it, your choice.

How To Brew
Latest Revised edition (in metric)

• Publication date 01 Jun 2017

 

[kadmium]

How To Brew
Latest Revised edition (in metric)

• Publication date 01 Jun 2017

To be fair to Grmblz, it's only in the last few years Llalemand and Fermentis recommended not oxygenating wort with dry pitch. Things change, and JP book is a good basic read.

I see no real harm in hydrating, but putting in crushed up centrum pills ain't gonna do good, and will probably do harm. As stated, vitamin c in baking helps elasticity. Making the leap from "sourdough uses yeast and vitamin C therefore it must be good for beer" is just that. A leap.

 

[Coalminer]

To be fair to Grmblz, it's only in the last few years Llalemand and Fermentis recommended not oxygenating wort with dry pitch. Things change, and JP book is a good basic read.

I see no real harm in hydrating, but putting in crushed up centrum pills ain't gonna do good, and will probably do harm. As stated, vitamin c in baking helps elasticity. Making the leap from "sourdough uses yeast and vitamin C therefore it must be good for beer" is just that. A leap.

Was not advocating Vitamin C, Asprin or any other additive
I rehydrate my dry yeast as a matter of course (when I rarely have occasion to use it) as per manufacturers instructions, not Palmer's.
Just making an observation that the book has had 4 revisions since the online basic version was available
Saying that, the printed book is a far better read than the free version

 

[Nullnvoid]

Was not advocating Vitamin C, Asprin or any other additive
I rehydrate my dry yeast as a matter of course (when I rarely have occasion to use it) as per manufacturers instructions, not Palmer's.
Just making an observation that the book has had 4 revisions since the online basic version was available
Saying that, the printed book is a far better read than the free version

I think he was referring to Grandpa about the vitamin c.

He was referring to you in regards to the Palmer book.

 

[Grmblz]

Vitamin C is an antioxidant so it will be scavenging up free oxygen in the water which is counter productive to yeast growth.

I believe you will also find the vitamin C used in baking is because it breaks down the glucan in the flour to elasticise it more. I once saw a bloke add a little diesel to his engine oil when flushing, I wonder if that would help me flush my kegs better. Surely if it worked for that, logic states it must be good for flushing things out.

If you decide to go against what the yeast manufacturers state to do, that's up to you. But even JP states that Llalemand and Fermentis do not recommend hydrating yeast.

The only time I rehydrate yeast is when making mead, and that's using something like D47 wine yeast and I use Fermaid Protect hydrating powders and then do TOSNA nutrient additions.

If you want to make fluffier bread add Vitamin C, if you want to make stressed, unhappy and oxygen deprived yeast add vitamin c.

On citric acid,
Lallemand: "In most cases,dry-pitched fermentations proceed normally without any problems. However, this option is not recommended in high gravity worts (above 16ºP or SG 1.065) or in soured worts with low pH."
Citric is going to lower the pH so rehydrating as opposed to direct pitch is deemed necessary, although how rehydrating in an acid environment which is clearly not beneficial to dried yeast is beyond me.

Of greater interest is:
AFTER REHYDRATION, BACTERIAL CONTAMINATION CAN DEVELOP IN THE SLURRY. For that reason, we recommend a rehydration in sterile hopped wort compared to sterile unhopped wort or sterile water. The iso-alpha acids (ideally above 5ppm, the equivalent of 5 IBU) present in the media will protect it from Gram + bacterial development and will not affect the rehydration process of the ADY

I've been aware of bacterial presence in dried yeast, hence the need for speed when rehydrating it, ang getting it into the wort post haste, but it's never occurred to me to use a "hopped" wort for rehydration (I've just used boiled, cooled tap water) and the same goes for my starters, boil 100gms dme in 1L of water, cool and pitch, in fact somewhere in the back of my head is the thought that hops actually aren't beneficial to yeast, no idea where I got that thought from, perhaps it was an assumption that because hops are anti bacterial they also have a negative effect on yeast, dunno.
I only rehydrate these days if it's specifically required, but I do make starters when using my yeast bank, and I think I'll change my process to include hops in the starter wort.

 

[Grmblz]

Just making an observation that the book has had 4 revisions since the online basic version was available
Saying that, the printed book is a far better read than the free version

I know, and I wonder which version grandadrob has been referencing? "rehydrate in a cup of water?"
Your assumption that he has the latest 2017 version is unlikely to be correct given how long he has been brewing for, and who buys a book they already have just because it now has metric conversions, and some updates, especially in the UK where many still operate in Imperial, meh! (especially old farts like rob and myself)
"I need 2.4 mtrs of 4 x 2" gets some very strange looks at my local hardware store.

 

[Coalminer]

I know, and I wonder which version grandadrob has been referencing? "rehydrate in a cup of water?"
Your assumption that he has the latest 2017 version is unlikely to be correct given how long he has been brewing for, and who buys a book they already have just because it now has metric conversions, and some updates, especially in the UK where many still operate in Imperial, meh! (especially old farts like rob and myself)
"I need 2.4 mtrs of 4 x 2" gets some very strange looks at my local hardware store.

I did not assume he had the latest version book at all, or any version. I really suspect is probably reading the online version.