Newbie Yeast Question

I have a couple of questions regarding yeast. First the back story....

I have a six pack of Great Divides Colette which is bottle conditioned. I know that some breweries bottle condition with a different strand then they ferment with, however I found a clone recipe that someone did on here with harvested bottle yeast and it is confirmed that the bottling yeast is the same as the fermenting yeast.

So my question is, what's the best way to harvest it? I've seen a few different methods online and the preliminary steps have been the same, which is where I'm at. I carefully poured out the beer, left a few ounces of beer/yeast in the bottle, sanitized, and recapped, and put back into the refrigerator.

So it's my understanding that I pretty much make a small starter, let it ferment for a few days, and then make medium starter, pour the original starter into that, let it ferment for a few days, and then repeat until I have enough yeast. Does anyone have specifics on how much DME/water to use and how many steps? Should I cold crash between steps? How do I estimate when I have enough yeast to pitch at a later date?

Now my second question. How long will is last in the fridge? I want to harvest the yeast to be used in a saison (obviously) that I'll brew next March for drinking in May. Should I wake up my yeast after a few months, do some type of fermentation, cold crash it, then use it in March?

Well, I'll take a stab at this. I've made lots of starters, but I've never bottle harvested, so I don't know how much yeast you'll be starting with so this is just a WAG. Go with 3 steps to start... .25l, .50l, & 1.0l to build up the cell count. Ratio is 1g DME to 10ml water, so a .25l starter would be 25g DME to 250ml water. You have the idea right as far as process, that is make the starter, let it ferment a day or two, cold crash it for a couple days, decant the liquid, and repeat with subsequent steps until done.

And, yes, I would build another starter about midway between your first starter and brew day to build the population back up because a lot of the cells will die off in the meantime.

Now for some rough numbers, which I got from yeastcalc...

Let's assume you harvested 10 billion cells from the bottles, which seems to me to be a reasonable number. To be conservative, let's also assume they are 3 months old at this point. According to yeastcalc, that's 32% viability, so we have 3.2 billion viable cells. If you use a stir plate for your starters, you'll have the following cell counts after each step...
.25l = ~19 billion
.50 = ~67 billion
1.0 = ~184 billion

Cold crash, decant, and pour the slurry into a sanitized mason jar topped off with distilled water.

4 months down the road, viability is 11%, so out of your original 184 billion cells, only about 20 billion are still viable, so you make another starter to freshen it up conisting of 2 steps...

.50l = ~70 billion
1.0l = ~189 billion

Cold crash, decant, and save again.

This is the basic idea. Go to yeastcalc and run some scenarios to see what makes the best sense to you and your aeration method. For now, you don't need to know OG or batch size, but you will need it when planning your final starter for brew day.

I hope this is helpful. Good luck!

Those steps are fine, but it is helpful to ramp up to 1.040 wort (10:100 ratio) over the steps. For example, use 1.020 wort for your first step, 1.030 for the second, and 1.040 for all others. It helps rouse the yeast without stressing them too much.

Thanks for the help, I think I at least have a place to start. Just a quick follow up question....

How can I calculate the OG? Is there an online calc I can use that I can enter the amount of DME and water and it will determine the OG?

Also, should I just wake the yeast up every four months, do two starters and then cold crash until I'm ready to use?

As far a starting yeast count goes, it depends on the brewers methods. But as an example, my understanding is that sierra nevada filters their beer, and then adds back the equivalent of one fifth of a vial of yeast per 5 gallons. So that's 20 billion cells spread across 50 bottle, or around 400 million per bottle, ignoring whatever cell growth occurs.

I probably wouldn't start with anything bigger than maybe 100 ml for the first step.

wsender said:

Thanks for the help, I think I at least have a place to start. Just a quick follow up question....

How can I calculate the OG? Is there an online calc I can use that I can enter the amount of DME and water and it will determine the OG?

Also, should I just wake the yeast up every four months, do two starters and then cold crash until I'm ready to use?

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10g per 100mL is ~1.040. So 5g/100mL would be 1.020 and 7.5g/100mL would be 1.030.

So any have any idea of the shelf life of the yeast? So far one comment alluded to that I should wake it up every 4 months then cold crash it again. I'd love more input if it's available.

Personally, the oldest yeast I've used was about 3-1/2 months and it started back up with no problem. I haven't tried with anything older than that yet. I've read posts from others who have stated that they've had success with yeast that was more than 6 months old, and a few have even claimed success with yeast that was over a year old. You could probably just build your colony now and then do it again when you are about to brew in 9 months or so, but just be aware there is an outside possibility that there will be no viable cells remaining by then, but more than likely it'll be fine. Might be a few days lag time before the first step becomes active, but it'll problaby come to life all right. But, if you want to be sure you'll have viable cells, make up another starter halfway between now and brew day.

LLBeanJ said:

Personally, the oldest yeast I've used was about 3-1/2 months and it started back up with no problem. I haven't tried with anything older than that yet. I've read posts from others who have stated that they've had success with yeast that was more than 6 months old, and a few have even claimed success with yeast that was over a year old. You could probably just build your colony now and then do it again when you are about to brew in 9 months or so, but just be aware there is an outside possibility that there will be no viable cells remaining by then, but more than likely it'll be fine. Might be a few days lag time before the first step becomes active, but it'll problaby come to life all right. But, if you want to be sure you'll have viable cells, make up another starter halfway between now and brew day.

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Yeah probably a good idea to give yourself a week before brew day if you're stepping up an old washed yeast stock. That way if it lags or you need to do additional steps, you have time.

I just made an IPA with reused Wyeast 1450 that I had stored in the fridge 9 months. I did a 2 step starter to wake it up and get the cell counts I needed. It fermented just like it did the first time I used it. I had the yeast, which was rinsed from the primary, stored in a mason jar with boiled water(then cooled) in my fridge at 34F. As it got older you could see that some of the yeast was changing color, i.e. dying. There was still a good layer of white/creamy yeast though, so I new I still had some good yeast. I've started freezing yeast recently, and according to reports the yeast can last over a year easily.

Alright, thanks for all the help; I really do appreciate it.

One last question though. When I'm doing the initial step up, three steps starting at 1020 to 1040, how long should I do each step. I will be using a stir plate.

With a stir plate, you want to go 24 hours max or you risk stressing the yeast. The exeption to that would be on the first step with older yeast where it may take an extra day or three to wake them up from their long slumber. After you have done a few starters, you'll be able to look at the color of the wort and tell when it's gone long enough, as it will have turned from a translucent brown to a creamy tan.

wsender said:

Alright, thanks for all the help; I really do appreciate it.

One last question though. When I'm doing the initial step up, three steps starting at 1020 to 1040, how long should I do each step. I will be using a stir plate.

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I tend to not use a plate for the first step. The yeast are very fragile and stressed. Plus it really helps to be able to see the activity when a little teensy tiny krausen forms and you can see the very thin yeast layer at the bottom grow. Once you're past that step, go ahead and throw it on the stir plate. Keep in mind that first step can take a while in some cases.