Yeast starters and equipment

[Drewgong]

Gday fellas after a recent issue with diacetyl (still unsure if its infection or lack of diacetyl rest) Ive decided to change two things as well as some new beer and gas lines.
1, Yeast starters . Ive always used dry yeast and just added to fermenter
2, Oxygenating my wort
I always double batch using two fermenters 21 litres in each og can be anywhere from 140-160. I like the idea of using a different yeast in each fermenter for experimental purposes. What size erlenmeyer flasks do i need and are magnetic stir plates as must? im guessing ill need two of these? does the yeast stay on the stir plate the whole time up until pitching?

 

[RoneMac]

Have you considered trying to rehydrate the dry yeast?
Diacetyl can be cleaned up b giving the yeast a little more time before lowering the temperature of the beer.
5L erlenmeyer flasks are very usefull to have around.
The stir plates I'm aware of are single flask units, so you will need one for each yeast strain you are making a starter for at the same time.
The yeast should stay mixing up until time to pitch. Make sure you pitch by pouring gently so the flea doesn't drop into the wort.
I've had success oxygenating wort while homebrewing by making sure the wort is splashing around when transfering to the fermenter and then giving the whole fermenter a quick vigourous shake once the lid was on. An aeration setup ended up being just another bit of gear that I needed to clean that I could avoid using.

 

[sirosis]

I use 3 litre Erlenmeyer flasks to do yeast starters, start with 2 1/2 litres and boil down to 2 litres before adding yeast cells. Using a stir plate is a must to get a good yeast starter, just set and check a couple of times a day. I find it usually only takes a couple of days for it to do it"s work.

 

[Drewgong]

I use 3 litre Erlenmeyer flasks to do yeast starters, start with 2 1/2 litres and boil down to 2 litres before adding yeast cells. Using a stir plate is a must to get a good yeast starter, just set and check a couple of times a day. I find it usually only takes a couple of days for it to do it"s work.

Can you add too much yeast? is there a formula/ measurement

 

[RoneMac]

Can you add too much yeast? is there a formula/ measurement

You can add too much yeast, but it is tricky to do on a homebrew scale.
Jump on your favourite search engine and search for "yeast pitch calculator" and you should be able to find something to crunch the numbers for you easily enough. You generally want to increase each pitch by a factor of 10. So you will need to add around 2L of started for your 21L of wort.
In my experience, making starters has been primarily used for growing a small amount of yeast into a large amount of yeast. Traditionally, a dry yeast pack (if not damaged) contains sufficient live yeast to ferment out a 20L batch of wort, making a starter not really necessary.
Don't get me wrong, it's fun to make a starter and see the yeast getting active prior to introduction to wort, but it's an extra vessel or two you need to sanitise, a bunch of equipment you need to buy, a bunch of work you need to do, when dry pitching fresh packs works well.

 

[Reg Holt]

Gday fellas after a recent issue with diacetyl (still unsure if its infection or lack of diacetyl rest) Ive decided to change two things as well as some new beer and gas lines.
1, Yeast starters . Ive always used dry yeast and just added to fermenter
2, Oxygenating my wort
I always double batch using two fermenters 21 litres in each og can be anywhere from 140-160. I like the idea of using a different yeast in each fermenter for experimental purposes. What size erlenmeyer flasks do i need and are magnetic stir plates as must? im guessing ill need two of these? does the yeast stay on the stir plate the whole time up until pitching?

No need for oxygenating the wort if you are using dry yeast, yeast dependent, someone put up a post of what Fermentis recommends, probably in one of the yeast threads. Just sprinkle or re hydrate.

 

[Drewgong]

No need for oxygenating the wort if you are using dry yeast, yeast dependent, someone put up a post of what Fermentis recommends, probably in one of the yeast threads. Just sprinkle or re hydrate.

Planning to broaden my horizons and start trying some liquid yeasts

 

[hoppy2B]

I just use an ordinary jar for most of my starters. Sometimes I use lab bottles. Bringing the sugar/dex/malt extract and nutrient solution to a boil in the microwave with the lid loosely sitting on top, while observing closely to avoid a boil over, is all it takes to prepare. Once cooled add yeast, replace lid loosely and cover with some glad wrap for safety. Place label on it to avoid mix ups, and you're done.

 

[MHB]

People keep telling you that Sugar (Sucrose) isn't really the best thing to add to a starter - they are right, it isn't.
Just use a LME or DME wort in the 1.030-1.040 range, a little yeast nutrient (one of the good ones - not just DAP) is the best
When making a starter are trying to get a larger population of healthy yeast, the perfect environment would be the wort its going to be brewing, given that most of us culture up the yeast before making the wort, using extract is about as good a food as we can get. The extra vitamins, minerals and readily available proteins and sterols in a good nutrient coupled with the food provided by extract really is the best.
Using sugar on the other hand forces yeast to use resources to make Invertase and forces other metabolic pathway's that aren't really the most conductive to more of healthy yeast.
O2 is just as important as any other nutrient during yeast reproduction, boiling the wort is good for sterilisation, but it ejects most of the O2, if you want to get good reproduction you need to have a way to get O2 into the wort and good growth media.
Mark

 

[RoneMac]

People keep telling you that Sugar (Sucrose) isn't really the best thing to add to a starter - they are right, it isn't.
Just use a LME or DME wort in the 1.030-1.040 range, a little yeast nutrient (one of the good ones - not just DAP) is the best
When making a starter are trying to get a larger population of healthy yeast, the perfect environment would be the wort its going to be brewing, given that most of us culture up the yeast before making the wort, using extract is about as good a food as we can get. The extra vitamins, minerals and readily available proteins and sterols in a good nutrient coupled with the food provided by extract really is the best.
Using sugar on the other hand forces yeast to use resources to make Invertase and forces other metabolic pathway's that aren't really the most conductive to more of healthy yeast.
O2 is just as important as any other nutrient during yeast reproduction, boiling the wort is good for sterilisation, but it ejects most of the O2, if you want to get good reproduction you need to have a way to get O2 into the wort and good growth media.
Mark

True. Culturing yeast in an environment close to the target wort is preferred and a decent oxygenation setup is great but not essential for for homebrew, especially when getting started and seeing if you even want to pursue this avenue of control.
Sugar for a starter and giving the fermenter a hell of a shake for oxygenation are far from gold standard processes, but they are cheap, easy, require gear that people probably already have lying around and will probably work.
I just wanted to float the idea that problem solving a potential diacetyl problem doesn't need any real investment in new materials or equipment. Give it an extra day warm and see if the yeast just wasn't quite finished and was crashed out too early. Give the fermenter a shake at pitching and that might just be enough to get a little more oxygen into the wort without buying an oxygen cylinder, sterile filter, air stone, etc.
There is nothing wrong with buying some new toys and learning some new skills, but sinking money into a problem may not solve it.

 

[hoppy2B]

Yeah, Mark's way of doing things is a bit pish posh for my tastes tbh. Granted, there is some scientific merit in the things he says, I think one can take things to extremes.

Brown sugar isn't the best thing for yeast apparently, but molasses is commonly used by commercial yeast labs. Take a Wyeast smack pack - stinks of it. I use a mix of sugars including malt extract. I don't think you need to be too fanatical.

And sure you will get more yeast if you oxygenate your wort, but is it really necessary? I've read stuff from so called experts who suggest nothing should be oxygenated ever.

I make my starter up at 1060 and have no issues. That will also raise the yeast cell count. This morning I pitched 2 jars of yeast starter into my Porter because I wanted a higher count. No problemo.

If you buy a conical flask you are guaranteed to break it at some point. I had one and I don't see the point getting another one.

At the end of the day if someone wants all the bells and whistles that is up to them. The point I want to make is that you really don't need a stir plate and conical flask to culture yeast. Culturing yeast is really simple.

 

[RoneMac]

There is a lot you can do for virtually no additional cost. Erlenmeyers and stir plates are great and I don't really have anything negative to say about them, but I am in complete agreement with hoppy2B. Give it a crack on the cheap end. A jar isn't as good as an Erlenmeyer, but it is good enough to get started.

 

[Drewgong]

Cheers for the feedback fellas ive been oxygenating for a few years by shaking the **** out of the fermenter. I just hate the feeling you get when you dont hit the expected fg or sometimes you even get a stalled fermentation i want to step things up and give my beer the best possible chance. I dont mind spending a bit of money on brew gear theres worse habbits out there.
So i just bit the bullet and ordered two stir plates two 3l flasks pure o2 kit yeast nutrient few other bits n pieces .

 

[MHB]

The pair of you are both seriously wrong, I'm fairly confident that there is little point but here goes...
Wyeast don't culture on molasse, no one in the brewing industry does (I also know someone who did a tour of their plant and they had pallet loads of DME).
We don't use simple sugars for very good reasons, Yeast is incredibly mutable, this is why anyone who propagates yeast commercially is always working up from single cells, feed yeast sugars for a couple of generations (that's about 2-3 hours/per) and there is a fair chance that it (or some of it) will "forget" how to handle anything else i.e. the more complex sugars in wort, which sort of negates the point of having lots of yeast.
Molasses is widely used in the ethanol and baking industry as a culture medium for yeast, but they want to have lots of yeast that is happy eating sugars.
Best answer is just to use LME/DME with nutrient for brewing yeast propagation.

If you understand and work with yeasts life cycle you can achieve the two main goals of yeast propagation easily and at very low cost. Sure having aeration and mag stirrers makes it easier and gives you better control but it isn't necessary.

The aim of yeast propagation is to have more of healthy yeast, its pretty easy to get this half right and have more yeast that really isn't in the right condition to ferment a wort, that has lots of mutations or lacks the stored energy reserves that make it ready to use, or able to finish off the job it starts i.e. throws lots of VDK, stalls, wont flock or goes too early....
If you cant supply enough Oxygen to keep the yeast toped up with sterols and glycogen, run the yeast through its full fermentation cycle (4-5 days) decant off the expended wort and start again with fresh well aerated wort. That way it will at least be healthy and ready to work.
One of the most damaging thing we can do to yeast is to try to get it to reproduce and starve it of oxygen, oxygen is a nutrient in terms of yeast propagation, yeast will try to reproduce and will expend its internal reserves, this just gets worse and worse with each generation. Biologically oxygen is generally highly available, yeast hasn't really got a mechanism to cope with limited availability, lots yes none yes some no! Putting yeast on a starvation diet isn't smart, better to grow it in steps.
Anyone thinking they can get enough dissolved oxygen (DO) into either a wort or starter by just shaking or splashing isn't really doing themselves any favours. Do a bit of reading up on how much DO you get from various aeration methods. There are very good reasons why 10ppm is recommended and you wont get even half that without proper aeration.

If you just work with yeast it will work for you.
If you want some good reading, PM your email address and I'll send you some good basic stuff (too big to post here).
Mark

 

[Drewgong]

The pair of you are both seriously wrong, I'm fairly confident that there is little point but here goes...
Wyeast don't culture on molasse, no one in the brewing industry does (I also know someone who did a tour of their plant and they had pallet loads of DME).
We don't use simple sugars for very good reasons, Yeast is incredibly mutable, this is why anyone who propagates yeast commercially is always working up from single cells, feed yeast sugars for a couple of generations (that's about 2-3 hours/per) and there is a fair chance that it (or some of it) will "forget" how to handle anything else i.e. the more complex sugars in wort, which sort of negates the point of having lots of yeast.
Molasses is widely used in the ethanol and baking industry as a culture medium for yeast, but they want to have lots of yeast that is happy eating sugars.
Best answer is just to use LME/DME with nutrient for brewing yeast propagation.

If you understand and work with yeasts life cycle you can achieve the two main goals of yeast propagation easily and at very low cost. Sure having aeration and mag stirrers makes it easier and gives you better control but it isn't necessary.

The aim of yeast propagation is to have more of healthy yeast, its pretty easy to get this half right and have more yeast that really isn't in the right condition to ferment a wort, that has lots of mutations or lacks the stored energy reserves that make it ready to use, or able to finish off the job it starts i.e. throws lots of VDK, stalls, wont flock or goes too early....
If you cant supply enough Oxygen to keep the yeast toped up with sterols and glycogen, run the yeast through its full fermentation cycle (4-5 days) decant off the expended wort and start again with fresh well aerated wort. That way it will at least be healthy and ready to work.
One of the most damaging thing we can do to yeast is to try to get it to reproduce and starve it of oxygen, oxygen is a nutrient in terms of yeast propagation, yeast will try to reproduce and will expend its internal reserves, this just gets worse and worse with each generation. Biologically oxygen is generally highly available, yeast hasn't really got a mechanism to cope with limited availability, lots yes none yes some no! Putting yeast on a starvation diet isn't smart, better to grow it in steps.
Anyone thinking they can get enough dissolved oxygen (DO) into either a wort or starter by just shaking or splashing isn't really doing themselves any favours. Do a bit of reading up on how much DO you get from various aeration methods. There are very good reasons why 10ppm is recommended and you wont get even half that without proper aeration.

If you just work with yeast it will work for you.
If you want some good reading, PM your email address and I'll send you some good basic stuff (too big to post here).
Mark

cheers mate there was a chart i stumbled across that showed how much oxygen gets into wort by shaking it , by using fish tank pump and by using pure o2 i cant remember the exact figures but roughly 30 seconds of pure o2 added 5 times the oxygen as 20 minutes of shaking fermenter

 

[RoneMac]

Thanks for the offer to help.
I work professionally with yeast. I was trying to provide some cost effective alternatives to try before buying new equipment.
I sometimes see people get overwhelmed with the advice given to them for managing yeast at a homebrew scale. I'm happy to talk growth rates, nutritional requirements and storage conditions until the cows come home.
I may have approached this a bit low tech, but that's one of the things I love about homebrew. You CAN get away with shaking the hell out of a fermenter to oxygenate. Dry yeast packs are really cheap so I can just throw two in and not worry about messing around with a starter if I want to save a bit of time. These are things that are impractical on a larger scale so maybe I relish in the luxury of being able to do them on a smaller scale.
Sorry if I gave the implication that yeast health was not important. It's just much easier to work around at a homebrew scale.

 

[sp0rk]

Brown sugar isn't the best thing for yeast apparently, but molasses is commonly used by commercial yeast labs. Take a Wyeast smack pack - stinks of it. I use a mix of sugars including malt extract. I don't think you need to be too fanatical.

Baking yeast is grown on molasses (word is some of the newer distilling yeasts are too), brewing yeast generally is not from what I've found in my research

 

[Drewgong]

Thanks for the offer to help.
I work professionally with yeast. I was trying to provide some cost effective alternatives to try before buying new equipment.
I sometimes see people get overwhelmed with the advice given to them for managing yeast at a homebrew scale. I'm happy to talk growth rates, nutritional requirements and storage conditions until the cows come home.
I may have approached this a bit low tech, but that's one of the things I love about homebrew. You CAN get away with shaking the hell out of a fermenter to oxygenate. Dry yeast packs are really cheap so I can just throw two in and not worry about messing around with a starter if I want to save a bit of time. These are things that are impractical on a larger scale so maybe I relish in the luxury of being able to do them on a smaller scale.
Sorry if I gave the implication that yeast health was not important. It's just much easier to work around at a homebrew scale.

cheers mate i should of mentioned that i was already shaking the fermenter but i only ever done this for like a minute ive always added one packet of yeast for below 1050 and 2 if over that. Most of the time i never had problems just occasionally my fg would be higher than usual or sometimes id get stalled fermentation. As i said to Mark i just want to give it the best chance and i dont mind a bit of extra playing around in the brew shed

 

[goatchop41]

cheers mate there was a chart i stumbled across that showed how much oxygen gets into wort by shaking it , by using fish tank pump and by using pure o2 i cant remember the exact figures but roughly 30 seconds of pure o2 added 5 times the oxygen as 20 minutes of shaking fermenter

Using an SS paint stirrer attached to a drill will get your DO levels somewhere in the middle of the other two options that you've mentioned - certainly an easier and cheaper option than a full O2 set up, and much better than just splashing the wort around

 

[Drewgong]

Using an SS paint stirrer attached to a drill will get your DO levels somewhere in the middle of the other two options that you've mentioned - certainly an easier and cheaper option than a full O2 set up, and much better than just splashing the wort around

Cheers mate not a bad idea however o2 kit is already on its way i think it was around $90 from kegland