Yeast starter question

Hello I started a yeast starter with a 1332 Northwest Wyeast after I smacked the pack and waited 3 to 4 hours the pack expanded but not as much as my other Yeast packs I have smacked get.The date is 10 Nov 10 on the pack.It has been in a frig since Jan.
My question is the pack to old and in my starter how will I know my yeast is good in the starter. I am using a 6 ounce wort which has been chiller in a 1000 ml flask. I am using a foam starter. This is my first starter.
Thanks

you want to let the starter ferment at normal fermentation temps, not in the fridge. Not sure what a "foam" starter or a 6 ounce wort are. Do you mean 6 oz of dme in 1 litre????

Somebodys been into the homebrew!!!

More than likely your yeast has very low viability. (10%) If your going through the trouble of making a starter than my suggestion would be to dump what you have and start with a more recent pack of yeast. Anything over 2 months is pushing it... using a different yeast that is fresh is better than the right yeast that is old.

Geez I just proof read my question and it sounds like I drank the starter , But yes I used 6 oz of DME to a 1000 ml of water.also I have a foam stopper, WHYB yes I am thinking of just ordering a new pack, I do have a dry yeast I can use but I like the Wyeast better.

WHYB said:

More than likely your yeast is has very low viability. (10%) If your going through the trouble of making a starter than my suggestion would be to dump what you have and start with a more recent pack of yeast. Anything over 2 months is pushing it... uUsing a different yeast that is fresh is better the right yeast that is old.

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It's going to be well below 10%. The calculators I'm aware of don't calculate below 10%, but you will get that kind of low viability in about 4 months - and this is older than 9 months.

Obviously, there's SOME viable yeast if the pack swelled. But it will be very small.

If I didn't want to just buy new yeast, I would start it off in a 100ml starter - that's about 10g (or 1/3oz) of DME. Then I would step it up 10-fold, which is a 1L starter with 100g (or 3.5oz) of DME. That should bring the viability to about 50billion cells, or basically equivalent to a 50% viable smack pack. I have a stirplate though, and this is all assuming the use of one. The 50B cell count is a very rough estimate, but with a basic idea of the very low initial viability (I'd say under 1%) and the two step-ups (multiple step ups of appropriate sizes actually produce increasingly consistent cell counts), it should be a good enough estimate.

From that point, you can use MrMalty or another calculator to figure out what to do with 50% based on the gravity of the wort you're ultimately pitching into.

Drank the starter... nice...

Sorry to say but, if you want to brew soon and your only options are the dry yeast vs the starter you have, then I would go with the dry...

WHYB said:

More than likely your yeast has very low viability. (10%) If your going through the trouble of making a starter than my suggestion would be to dump what you have and start with a more recent pack of yeast. Anything over 2 months is pushing it... using a different yeast that is fresh is better than the right yeast that is old.

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Save the yeast! Yeast have rights too!

The worst case scenario is you will have to do a two stage starter.

To communicate more easily with other forum members it helps to speak in terms we use to describe starters. Usually you will say I'm using 1000ml or 1qt or 1L starter referring to the amount of liquid not the size of the flask/container. If you want to be specific you can spec the gravity of the wort you are using ie 1040 or 1 cup per 1000ml water etc. That might be why people are confused with your question.

What you might want to do to guarantee you have enough yeast is do a 500ml starter, then crash cool (aka fridge for two days), decant and then do a 1000ml starter and pitch when it is at high krausen (about 12- 24hrs).

You mentioned this was your first starter... keep in mind each time you do a starter you run the risk of contamination and if you don't have a stir plate you could be looking at 3 step ups to get to 100 b. (Your 1L flask limits your growth potential)

Thanks for the great advise ,I looked this morning and my starter has the cake on the bottom.
I will order some more, but I am going to play with this one.I will test the gravity when I get home from work tonight ,what should the gravity run about?
I love this strain in other kits.This is my first step to go all grain.

Are you asking about the gravity of the starter? I normally don't check this, if you keep the temp up (75-90) you should see everything completed with in 36 hours.

The final gravity will depend on quite a few things. Most notably, yeast health, the OG of your starter and the attenuation potential of your yeast strain. I estimate your OG to be around 1.070ish, multiply this by the attenuation rate 69% for your strain. Your looking at around 1.022ish (24-36hour mark) if all goes according to plan.

Let us know what you come up with ...

When I fridge and decant my starters, I usually will check the gravity, taste it, smell it, if I had a microscope I would probably try to use it too!.

I figure any information I can gain about how the starter is performing will help me make a better beer from it. An example of this, is if your 1.040 OG starter has a FG of 1.002 then you can bet you have an infection as your SG reading should not be that low (for normal yeast). Have not had that happen yet, cross fingers touch wood.

Clem

Day 2 my yeast starter sure has a lot of activity going on.It is bubbling and churning pretty good and a large cake on the bottom of the flask.I will check it tonight then I guess I will put in frig, decant and maybe run one more starter off this one with the cake.Does that sound correct? I am being very careful with sanitizing everything.Thanks again for your help.

gjsumm said:

Day 2 my yeast starter sure has a lot of activity going on.It is bubbling and churning pretty good and a large cake on the bottom of the flask.I will check it tonight then I guess I will put in frig, decant and maybe run one more starter off this one with the cake.Does that sound correct? I am being very careful with sanitizing everything.Thanks again for your help.

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What beer are you going to make with the starter? What is the expected OG of that beer?

I'd like to give you the best advice possible, but I'm just not sure of all the details. Have you only put the yeast into this single starter, or have you already stepped it up into a second batch of starter wort?

Also, the starter you have right now - 6.5oz DME for a 1000ml starter - is using waaay too much DME, by about double. Not only are you wasting money, but the higher gravity (and subsequent alcohol content) stresses the yeast.

Yes that is correct gjsumm. You can also go lower on starter gravity for the next step up. 4oz for 1L is plenty. I'd estimate you will have around 25 B cells at the finish of this first starter. 70 B cells at the finish of your second starter.

WHYB said:

Yes that is correct gjsumm. You can also go lower on starter gravity for the next step up. 4oz for 1L is plenty. I'd estimate you will have around 25 B cells at the finish of this first starter. 70 B cells at the finish of your second starter.

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No way he has 25B cells at this point, even if he used a stirplate.

You mentioned the pack did swell just not as much as normal. This would indicated that you do have some active yeast. I'm guessing your starting with 5B cells which is a good middle point, half way between the 10% and 1% viability that some estimators are predicting. The inoculation rate you've listed for the 1st starter gets you a growth factor of about 5.25. The nice thing here is even if the viability was lower (than 5B) this would in turn decreases the inoculation rate which then increase your growth factor, that is why I'd give out a guess of 25B. In the end it's only a "guess"

I bought a used stir plate off ebay do you leave the starter on it and turning all the time?

Yes, do you have a stir bar?

Things to remember yeast cell growth is determined by O2 and nutrient content of the wort they are in, this is why stir plates work so well they drive out the C02 move the yeast around to all the sugar that is in the wort (keep them in suspension) and provide access to lots of O2 hence why you see a massive increase using a stir plate. So if you pitch a small number of yeast into a really large starter you will see an increased growth rate but not necessarily what you would think. You could get the same growth from a smaller starter and lots of O2. As once the O2 is gone the yeast switch to alcohol production just like when pitched into a real wort. So just because you are seeing bubbles does not indicate increase in cell numbers or health.

To go even further when plating yeast and using a single colony of yeast to grow a starter you are infact growing billions of cells from a single cell and this can be done in a matter of days

plate yeast -> 48hrs single cell grows to a colony

10ml starter wort, pitch single colony only containing thousand or so cells aeration shaken -> 48hrs results 20 MYC/ml = 200MYC

100ml starter wort pitch 10ml wort aeration shaken 60 MYC/ml -> 48hrs results 6BYC

500ml starter wort pitch 100ml starter aeration O2 and stired 180-360MYC/ml -> 48hrs results 90BYC

1000ml Starter on stir plate 180-360MYC/ml -> 48hrs results 180BYC

(Info taken from Maltosefalcon website on yeast propagation & maintenance)

So my point is turning 5 BYC into 25 BYC using a stir plate is low balling it, step it up to a second starter on your stir plate and you will be fine.

Clem

Why do some people insist on detailing scenarios that don't pertain to someone’s particular question?

WHYB, I detailed a scenario as emjay doubted your numbers of 25 BYC and I believed your numbers to be correct and just gave an example of numbers I was working from on a recent plating culture I grew.

I also talked about O2 levels as the OP was asking about gravity and final gravity of your starter has little to do with cell numbers.

Sorry you missed my point, perhaps it was a long winded way of saying it.

Clem

WHYB said:

Yes, do you have a stir bar?

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Yep sure do on the stir bars ,so I guess I need to put this one in the frig decant then make my second batch but this time use the stir plate all the time.

Do you plan on brewing with this yeast or are you experimenting? Both?

emjay said:

What beer are you going to make with the starter? What is the expected OG of that beer?

I'd like to give you the best advice possible, but I'm just not sure of all the details. Have you only put the yeast into this single starter, or have you already stepped it up into a second batch of starter wort?

Also, the starter you have right now - 6.5oz DME for a 1000ml starter - is using waaay too much DME, by about double. Not only are you wasting money, but the higher gravity (and subsequent alcohol content) stresses the yeast.

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Well the OG suppose to be 1.052 on my Brown ale kit.About the DME amount I used what I saw on a you tube video.

Both on the yeast ,but mainly experiment to see what I can accomplish with it.Next batch calls for the same yeast.

gjsumm said:

Well the OG suppose to be 1.052 on my Brown ale kit.About the DME amount I used what I saw on a you tube video.

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All you have is a 1L flask? And I'm guessing you don't have a stirplate?

emjay said:

All you have is a 1L flask? And I'm guessing you don't have a stirplate?

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Yes I have a stir plate and only a 1 L flask I also have a stir bar.

The stir plate should really help things along... if you did a full 1 L on the next step you'd probably be over 100B, but if you wanted to brew a 1.052 with this yeast you'd still need another step up to get to approx 190B. Have you decanted yet?

gjsumm said:

Yes I have a stir plate and only a 1 L flask I also have a stir bar.

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Okay, well having a stir plate is good. If you had no stir plate and only a 1L flask, building up a proper starter would be totally unrealistic.

With a stirplate, it will still take a bit of time, but 2 more steps happens to create an almost perfect amount of yeast, if you're up to it.

Basically, you have to chill your current starter in the fridge so that the yeast crashes to the bottom. Pour out all the liquid on top, and use that yeast to pitch into another 1L starter (make sure you don't boil the yeast!)

Then make sure this new starter ferments completely, stick it in the fridge, and basically repeat so that you make another 1L starter with THAT yeast. But this one, you pitch into your batch when it's at the peak of fermentation (24-48 hours after pitching the yeast into it).

Essentially, you should build up that yeast with 2 more starters. Both the starters should be 1L, and made with 3.5oz of DME.

emjay said:

Okay, well having a stir plate is good. If you had no stir plate and only a 1L flask, building up a proper starter would be totally unrealistic.

With a stirplate, it will still take a bit of time, but 2 more steps happens to create an almost perfect amount of yeast, if you're up to it.

Basically, you have to chill your current starter in the fridge so that the yeast crashes to the bottom. Pour out all the liquid on top, and use that yeast to pitch into another 1L starter (make sure you don't boil the yeast!)

Then make sure this new starter ferments completely, stick it in the fridge, and basically repeat so that you make another 1L starter with THAT yeast. But this one, you pitch into your batch when it's at the peak of fermentation (24-48 hours after pitching the yeast into it).

Essentially, you should build up that yeast with 2 more starters. Both the starters should be 1L, and made with 3.5oz of DME.

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Thanks again for the help.

No problem. Let me know what you end up doing!

Ok so I decant the yeast from the frig and I added 1 liter of 3.5 oz DME wort. It is now on a stir plate.How long should I keep it on this step? Also when I took it out of the frig it was chilled I decanted it then added the 70 degree new wort,will it shock the yeast? Thanks again.

It might cause a bit of shock (but it won't kill them), if I'm decanting I will put the wort in the fridge also then add the wort when it is at the same temp. I figure this is like breakfast in bed for the yeast. They wake up and the food is right there!

Time to stir, stuff I have read conflicts with what I have observed so... reading says 24 hrs minimum anything over 36-48hrs ideal anything else is a waste of time. That said I have notice some starters stop showing any signs early than other and it is normally when pitching on smaller steps that they get the job done quicker others take longer. I'm still testing this theory but my thought is if you have the time wait the 48hrs even if nothing more appears to be happening.

Clem

Give it a good 3 days at least, actually.

Time for another lesson, LOL!

Even though all the yeast should be produced within about 12 hours, chilling and decanting has some significant differences from pitching without chilling/decanting that make it very important to be a fair bit more patient. You're putting the yeast into dormancy. When yeast goes into and comes out of dormancy, it is a pretty stressful time for it, and it depends on its stores of energy and nutrients.

Because of this, if you're going to chill and then decant, it is important to optimize yeast health by allowing it to build up reserves of glycogen and trehalose. It only starts building up glycogen reserves when it detects dormancy is imminent - that is, it waits until the remaining food supply is very low before even beginning to build up its reserves. Glycogen is not just a good source of energy for the yeast when the come out of dormancy, but it's also critical for cell maintenance during during that time. So it's critical that you let the starter ferment 100% *completely* before beginning to cool it.

Trehalose is an important stress-protectant that mostly begins to be made when the yeast is chilled. It starts quickly and builds up to optimal levels in about 48 hours. So after putting the starter in the fridge, you want to let it chill for at least two full days. It also ensures enough time for almost all the yeast to settle out.

Then, when you make one more 3.5oz/1L starter, do the same thing you already did with the 70° wort. In fact, it's the trehalose that makes this MORE than okay! Once the yeast warms up, it starts consuming the trehalose, and it won't take too long to use up almost all of it. But since THIS starter is the last step, and it's only 1L, you are best off skipping the chilling/decanting and pitching the yeast (with all the liquid) at peak activity - about 12-36 hours in. If you miss this window of time, you're best off letting it ferment completely and doing things the long way again.

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So to summarize:

1) Ferment this starter out COMPLETELY. Give it at least 72 hours (3 full days), although if you can wait an additional day or two in order to be 100% sure, that's even better.

2) Place in fridge (ideally 35-40°) for at least 48 hours.

3) Make one more 1Liter/3.5oz starter. When you're ready to add it to the yeast (at 70° is a good temperature), take the yeast out of the fridge, decant the liquid, and add the new starter wort .

4) Ferment on stirplate for 12-36 (ideally 18-24, IMO) hours, and then pitch the whole starter into your batch of beer-to-be!

5) If you miss the 36-hour window, do steps 1-3 again, except this time pitch the yeast into your batch in the fermentor. When you decant the liquid, it'll be much easier to pitch if you keep a bit of the liquid and swirl the yeast back into suspension, and then pouring that slurry into the fermentor.

That will be perfect. I am finally off this weekend.That will give me time on Saturday to start batch.

With respect to adding the whole starter to your fermentor. I've had some starters have a really sour smell to them, only ever noticed this when using a stir plate. I've been hesitant to add the entire starter in these instances and instead decanted and let the yeast rise to 65-70 on brew day then added a bit of the wort to the flask (to get the yeast back into solution) and pitching that into the fermentor. Seems to work well...

That's normal, especially on a stirplate, due to heavy oxidation. Since it's only a single liter, it won't contribute anything noticeable, and pitching it at peak activity is optimal anyways. With a much bigger starter though, I'd recommend the chilling/decanting method though.

Ok I had it on the stir plate for 3.5 days and have place it in the fridge will keep in there for 2 days then friday I will add my DME and third step.There is definitely more yeast now.
Here is a question,I can get pharmicutical grade glucose ,where I work will a small amount help it any ,also I do have some yeast nutrients will adding them help?

gjsumm said:

Ok I had it on the stir plate for 3.5 days and have place it in the fridge will keep in there for 2 days then friday I will add my DME and third step.There is definitely more yeast now.
Here is a question,I can get pharmicutical grade glucose ,where I work will a small amount help it any ,also I do have some yeast nutrients will adding them help?

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Don't use the glucose... glucose is really easy for yeast to eat, and if they're given too much it can even cause them to lose their enzymes that allow them to break down more complex sugars such as maltose. Even a relatively small amount can cause the yeast to go through a different kind of fermentation. Either way, you are already using the ideal amount of sugars with the 3.5oz of DME, and even if somehow the glucose can't hurt, it can't help either, so there is really no point. Also, if you ever need to use glucose, the corn sugar/dextrose that is sold to homebrewers is also glucose, and it's good enough (as long as it's boiled first!)

As far as the nutrient... yes. It is always a good idea to use nutrient, especially in an all-extract wort, and *ESPECIALLY* in a starter. Don't bother with it right now though. But when you boil the DME for your final step-up, definitely put some in there while its boiling, which will also help disinfect it.

Good to hear that everything's going so smoothly