Simple approach to culturing existing yeast

[jonnygreenwood]

Hey everybody,

Quick question. I've been looking into trying to culture a yeast strain that I can buy at the store--maybe a basic White Labs strain, for example--and reuse it for new batches of beer. I've read through some websites on growing yeast at home, but it seems terribly complicated and appears to require a lot of equipment. My thought is that people have been brewing beer for centuries without an autoclave or glass vials, right? So short of just setting some DME/water mixture in the windowsill and hoping for wild yeast, is there some simple way to culture store-bought yeast and reuse bits of it at a time over the course of multiple batches? Thanks.

 

[Pappers_]

Jonny

Try this method of harvesting and washing yeast , so you can reuse the yeast multiple times. I do this and its not too complicated at all - https://www.homebrewtalk.com/f163/yeast-washing-illustrated-41768/

 

[bigjoe]

The washing link is great. Its not culturing, but if you brew with the yeast every couple of months (or weeks) it should be viable. I know I used some WLP002 a while back that was 3 months old. I read posts about people buying one vial of a particular strain the use frequently and not buying another until the following year. I've also read posts about people storing it for a year or more in a mason jar and using it.

I've recently took 3 more kids in my house (nieces) on top of 3 of my boys. So I'm trying to cut cost anywhere I can. Washing yeast cuts about $7 off each batch I make.

As far as culturing goes. The process of culturing is a hobby unto itself as John Palmer said in a recent podcast on this topic.

 

[jonnygreenwood]

Very cool, thanks for the info on washing.

So, are you saying that if I wash my yeast between batches (as opposed to using the leftover cake from the last batch) and brew about once per month, a single vial of yeast will last me about a year? I was thinking that if you're getting 4 jars of yeast from each wash and using 1 of them to do a new batch of beer, wouldn't you be able to produce another 4 jars from that new batch as well, which would keep your culture going indefinitely? Or no?

 

[Bobby_M]

You can keep it going for as long as you're confident it's clean. No one's process is 100% sanitary. Every time you brew you have some potential spoiling bacteria in the batch. The process of collecting, washing, restarting, pitching etc adds a few more exposure points. It can only get worse, not better, as you reuse.

If you get it right, you save 6-7 bucks a batch. If you get it wrong, you lose $30.

 

[maida7]

This is the method I have just started to do.

1) Buy a fresh vial
2) Make a 2000ml starter on the stirplate. Let starter go for 48 hours to insure that it is finished. Then cold crash the starter to make sure the yeast is fully floculated.
3) decant the beer off the starter and split the slury in to 3 small jars. The ball 4 oz jelly jars are perfect for this.

So now you have 3 jars of yeast. Use 2 of these to make starters for you batches. The last one you use to make 3 more jars. and so on. Store the jars cold in the fridge.

If you do this you should probably limit yourself to just 2-4 strains of yeast and brew very regularly to keep your yeast stock fresh. The longer the sample sits waiting in the jar in the fridge the viability drops. I have no real data but a reasonable shelf life is 4 months. Ideally, you would not have them sit even that long.

I've picked 3 strains. WLP001, WLP300 & WLP530. With those I can brew all my favorite beers.

 

[bigjoe]

Its a calculated risk for sure. SO is making a starter. If you sanitary you'll reduce that risk dramatically. Nasty yeast can happen, I've only washed about 8 batches so far. So take what I say with that knowledge.

 

[maida7]

what I don't like about it is that you could use the infected yeast in several batches before you drink one and realize you have a problem. stress! RDWHAHB

 

[EvilGnome6]

This is the method I have just started to do.

1) Buy a fresh vial
2) Make a 2000ml starter on the stirplate. Let starter go for 48 hours to insure that it is finished. Then cold crash the starter to make sure the yeast is fully floculated.
3) decant the beer off the starter and split the slury in to 3 small jars. The ball 4 oz jelly jars are perfect for this.

I have switched from yeast washing to basically the same process with smaller starters and fewer vials. It's a lot less work than reclaiming and washing it from the primary. It also seems to offer far fewer chances for contamination.

 

[maida7]

I have switched from yeast washing to basically the same process with smaller starters and fewer vials. It's a lot less work than reclaiming and washing it from the primary. It also seems to offer far fewer chances for contamination.

Credit goes to EvilGnome6 I believe, I'm copying his method.

What turns me off to the washing is getting the glop out of the fermenter. I use better bottles and you can't flame the opening. The opening usually has the nasty caked up dried on glop. Looks like a breading ground for bugs.

With the lab flasks I use to grow up the yeast starters I can flame the opening and everything is super clean. Also no yeast washing is needed as there is no hops and very little trub in the starter wort :fro:

 

[bigjoe]

I like maida7 and Evil's method. I can see it being less.

maida7 You should know at the time of washing the yeast if its infected. Taste the beer. If it tastes like green uncarbed beer keep it. If you have any doubt dump it. Otherwise its a fairly safe bet your going to be OK. Don't get caught up in the hype. Practice good sanitation and I think everything will be fine.

I know there is an exposure potential with washing and getting an infection, but I think yeast is either far more robust than when I started brewing in the 90's, because you didn't hear anything about people washing yeast. I think its over played, but for good reason. I've only had one batch that was dumped due to infection. That was because I dropped my siphon hose on the kitchen floor and reacted by grabbing it and putting it back in the bottling bucket. In the 90's everyone I knew that reused yeast dumped it on a cake from a previous batch. I never did it I just sucked it up and bought more yeast.

 

[EvilGnome6]

I think the other benefit of propagating with starters is that you're always using a nice 1.040'ish wort. No worries about coming from a high gravity brew to a low gravity one, from a dark stout to a blond ale or from a hop bomb to a lightly hopped session beer.

The first starter gives you a chance to make sure the yeast is viable and clean. I take a gravity reading and a sip of the decanted starter beer to make sure I'm getting good attenuation and that there are no funky flavors.

The second starter takes off like gangbusters since the newly propagated yeast is so fresh.

Oh, yeah... I generally start the process about 6 days in advance of a brew day. That gives me plenty of time to make sure I have a viable culture and make alternate plans if the yeast is dead.

 

[bigjoe]

I think washing the yeast pretty much takes away the worry about going from an bigger to smaller beer or hoppy to sweet.

Point taken though. I'm getting a free smack pack of Wyeast 1214 today. I'll probably use the method with the starter and decanting to multiple jars.

Generally how much yeast are you getting from a a 2000ml starter spread across 3 jars? As usual I'm thinking of complicating the process and making a bigger starter so I don't have to use 2 of the jars on the first go around. Just pitch what I need to that day and save the rest for maybe 2 more starters.