A couple yeast starter questions I can't find answers to...

I've made only three batches of beer so far, the last two I made up a starter for. I used a 1L flask and mixed the water:extract per the instructions. Ive used wyeast for both, one was an activator, the other was a propagator. Both had very vigorous fermentation, and blew out the airlock. Is a whole pack of yeast too much for 1L?

No. The primary purpose of a starter is to increase the number of yeast.

Instead of an airlock, you can cover the flask opening loosely with a sanitized piece of foil (that's what I do, except that I don't use a flask, I use a large Ball jar).

You usually dont want to use an airlock on your starters. The goal is to get oxygen in there to facilitate yeast growth. Airlocks only let air out, so you arent achieving optimal yeast growth without the oxygen.

Why 1L starters? mrmalty.com has a pitching calculator that is very helpful, and I find that I usually need more than 1L starters (depending on the OG).

I'm gonna use tinfoil next time, since that seems to be what everyone uses. Is there a reason why? Also, why have my fermentations gotten so vigorous, when others say they don't see much happening?

I'm also building a stir plate before the next one, so I'll see how that helps. . .

coypoo said:

You usually dont want to use an airlock on your starters. The goal is to get oxygen in there to facilitate yeast growth. Airlocks only let air out, so you arent achieving optimal yeast growth without the oxygen.

Why 1L starters? mrmalty.com has a pitching calculator that is very helpful, and I find that I usually need more than 1L starters (depending on the OG).

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1L was what I bought at the LHBS, guess I should go get a 2L?

My starters get up as high as 2 gallons sometimes, but I don't have a stir plate and I rarely brew beer under 1.050.

Starter size just depends on the OG and how much yeast I have to make the starter. I have a 1 gallon glass jug and usually that is big enough for most ales- lagers are a completely different animal. If you LHBS has 1 gallon glass jugs get that, otherwise, the cheap gallon-o-wine jugs will work fine.

i use a bomber (22 oz beer bottle) covered with saran wrap loose (no rubber band) when i use liquid yeast

coypoo said:

Starter size just depends on the OG and how much yeast I have to make the starter. I have a 1 gallon glass jug and usually that is big enough for most ales- lagers are a completely different animal. If you LHBS has 1 gallon glass jugs get that, otherwise, the cheap gallon-o-wine jugs will work fine.

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I wouldnt use a 1 gal starter for a 5 gallon wort would I?

I save plastic milk jugs....use them once and throw away. Unless your making a lager or a high gravity beer a gallon milk jug will suffice.

Chaddyb said:

I wouldnt use a 1 gal starter for a 5 gallon wort would I?

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I made a 1.5 gallon starter recently for a barleywine. When it's anywhere near that large it's much more important to decant off as much of the clearish liquid as you can.

In regards to why you've had blowoffs with your starters and others don't seem to, I'm wondering if it might be the amount of area at the top of your starter... so, where the erlenmeyer flask gets really thin near the top of the vessel, is that where the top of your starter wort is? or is it lower down where the diameter is larger? If the top of the starter wort is in the low diameter area, that'd concentrate any krausen and make it more likely you'd have a blowoff.

Frodo said:

I made a 1.5 gallon starter recently for a barleywine. When it's anywhere near that large it's much more important to decant off as much of the clearish liquid as you can.

In regards to why you've had blowoffs with your starters and others don't seem to, I'm wondering if it might be the amount of area at the top of your starter... so, where the erlenmeyer flask gets really thin near the top of the vessel, is that where the top of your starter wort is? or is it lower down where the diameter is larger? If the top of the starter wort is in the low diameter area, that'd concentrate any krausen and make it more likely you'd have a blowoff.

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Just like any fermentation, each one will be different even if it is on a very small level.

I have had starters that have blown off like mad:


(the foil cap was on the floor after this one.)

And I have had starters that have done nearly nothing other than smelling nice and yeasty. Either way, all of my starters regardless of their visual characteristics have given me short lag times (as little as 3-4 hours on some instances), and full attenuation ranges for the style (in some cases slightly higher AT's than listed).

Regardless of activity rate, you should see co2 bubbles in the starter, and it should smell yeasty/doughy/bready, using those two senses together (sight and smell) will give you a clear indication of a healthy starter. Even if you use a stirplate, close inspection will reveal little bubbles of co2 swirling about the flask, or container.

Once again, each fermentation is different, so each starter may produce different results. The image shown above is a starter of WLP400 Belgian Wit Yeast, and each time I have made a starter with this yeast I have had a "yeastcano". However, I have used many yeasts, and for example when using WLP500 and WLP001 on a couple of occasions, I have had very little signs of activity other than the scent, and co2 bubble formation, but all have made great beer!

YMMV.

So, I'm still somewhat confused as to the size of the container I need to use. Am I better off using a bigger container, just so I have more volume of wort/yeast cake, or just so I have the available space IF i need to make a bigger starter? This starter business has me all confused.

Frodo said:

I made a 1.5 gallon starter recently for a barleywine. When it's anywhere near that large it's much more important to decant off as much of the clearish liquid as you can.

In regards to why you've had blowoffs with your starters and others don't seem to, I'm wondering if it might be the amount of area at the top of your starter... so, where the erlenmeyer flask gets really thin near the top of the vessel, is that where the top of your starter wort is? or is it lower down where the diameter is larger? If the top of the starter wort is in the low diameter area, that'd concentrate any krausen and make it more likely you'd have a blowoff.

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Yeah, when I fill up my 1L flask, its up by the top, so that makes sense why they blow over.

Chaddyb said:

So, I'm still somewhat confused as to the size of the container I need to use. Am I better off using a bigger container, just so I have more volume of wort/yeast cake, or just so I have the available space IF i need to make a bigger starter? This starter business has me all confused.

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Bigger will always be better in this case because it allows you to be a lot more flexible. 1 container to do all (or most) of your starters instead of having a bunch of different sized ones.

Go to mrmalty.com and start playing around with different gravities and see how the volume changes to get an idea of what size you'll need. Also, you can toggle "larger starters/less yeast packs" and the type of aeration (stirplate, shakining, etc) that will also effect the size of the starter

Don't forget the age of your yeast. If your LHBS doesn't run through yeast that fast your starters will increase dramatically.

coypoo said:

Bigger will always be better in this case because it allows you to be a lot more flexible. 1 container to do all (or most) of your starters instead of having a bunch of different sized ones.

Go to mrmalty.com and start playing around with different gravities and see how the volume changes to get an idea of what size you'll need. Also, you can toggle "larger starters/less yeast packs" and the type of aeration (stirplate, shakining, etc) that will also effect the size of the starter

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Hit the nail on the head here...

Why have multiple containers in different sizes?

Unless you want to make more than one starter at a time, which is what I have wanted to do on occasion, but planning far enough in advance can solve that dilemma.

Use a 1 gallon growler (less expensive option), or a 5000ml flask, those will be your two best sized containers for starters.

I'm lucky in that I can get my stirbar to spin in my growler, which has a concave bottom, I attribute it to the precision in making my stirplate. However, one of the LHBS here in town sells the 5000ml flasks for $32 and I get a 10% discount through our homebrew club:rockin:.

I hope to get one soon!

Anyhow, one other piece of advice I can give is learn how to wash yeast if you haven't already looked into it. There is a sticky on it in the yeast forum.

What you can do is make a 4liter starter, and save half of it for your next brew, and then when you are ready to brew again, make another 4 liter starter, save half, and so on....out to about 5-6 generations. You can also wash the yeast cakes from your actual beers saving even more yeast and money!

One smack-pack or vial can easily pay for itslef and then some, many times over. Washing yeast is uber simple, all it requires is sterile chilled water. makes total financial sense to me.

Chaddyb said:

So, I'm still somewhat confused as to the size of the container I need to use. Am I better off using a bigger container, just so I have more volume of wort/yeast cake, or just so I have the available space IF i need to make a bigger starter? This starter business has me all confused.

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I don't know if it'd work with a stirplate (I don't have one) but I typically use one of those 1 gallon glass wine bottles (Gallo?). For that 1.5 gallon starter I used a 5 gallon carboy. My point is it doesn't have to be a big decision - if you're using a stirplate obviously you'd have to make sure it'd work with that. Those 1 gallon wine jugs go for like $8 with wine in them...

Chaddyb said:

I wouldnt use a 1 gal starter for a 5 gallon wort would I?

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Nobody seems to have really addressed this. Yeah, you could totally use a 1 Gallon starter for a 5 Gallon batch of beer. You don't need to pour the entire thing in there, however. Once your starter has been going a few days, pop it in the fridge for another day, and the yeast will settle to the bottom in a nice cake. Then, pour or "decant" off almost all of the liquid, and slosh up the yeast really good before pitching. That way, you're pitching all the yeast propagated from a 1 Gallon starter, but you're only adding a quart or so of liquid to your wort.

vast_reaction said:

Nobody seems to have really addressed this. Yeah, you could totally use a 1 Gallon starter for a 5 Gallon batch of beer. You don't need to pour the entire thing in there, however. Once your starter has been going a few days, pop it in the fridge for another day, and the yeast will settle to the bottom in a nice cake. Then, pour or "decant" off almost all of the liquid, and slosh up the yeast really good before pitching. That way, you're pitching all the yeast propagated from a 1 Gallon starter, but you're only adding a quart or so of liquid to your wort.

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This has been addressed countless times. Do a search on it. If you research it enough you'll even get into cold pitching, yeast ranching, and tons of other topics yeast related that are way beyond the OP's original question.

In short, make a large starter, (gallo growlers will peobably work if you can get a stir bar to be stable) Make a stir plate (or buy one) stir starters, or brewers hardware have really decent deals. Make a bigger starter than necessary, chill for 48 hours, decan nearly all of your starter liquid after the yeast has settled, swirl, save some for next time, pitch the rest, done.

Don't make it more difficult than it needs to be, especially if you are just starting out, or getting into liquid cultures.

Fianlly, research, research, research.. look into it, doing a search here will provide tons of forum topics, but then you have to actually read them rather than just ask the question, and get answers you may not be completley satisfied with...

anyhow...everything you need to know is here, and there are planty of members willing to help, but start with mrmalty.com, by far the best source of starter info online!

Thanks for all the help and suggestions, to what I understand is a fairly simple thing, I just had some uncertanties, so I wanted to try to clear them up. Thanks all for your input.

I'm curious why anyone would have so much kreusan with a starter. The whole idea is to make yeast - a process that does not involve producing CO2. If there is sufficient oxygen in the solution, the yeast will grow and multiply. It is when they run out of oxygen, that they change their metabolism and make alcohol and CO2.

Therefore, I suspect lack of oxygen, too long a process (24-30 hours is all it needs) and too much food (malt) is causing yeast-making to turn into beer-making and giving the blow-off.

Brewham said:

The whole idea is to make yeast - a process that does not involve producing CO2. If there is sufficient oxygen in the solution, the yeast will grow and multiply. It is when they run out of oxygen, that they change their metabolism and make alcohol and CO2.

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Well you're correct though an oversimplifying. How would you ever know when multiplication has pretty much ended and fermentation has pretty much begun? And how would you keep the yeast from fermenting the sugars?

There are two mentalities with when to pitch a starter. I think what you're describing is pitching the starter at high krausen. The other way is to wait for fermentation to finish, let the yeast flocculate out, decant the liquid, and pitch the yeast slurry. I prefer the latter, that way I'm not pitching a bunch of nasty starter liquid into my beer.

Im starting to figure out that a lot of people like to decant the liquid and pitch the cake, I thin I will try this next time, as I have only pitched the whole thing...

Frodo said:

Well you're correct though an oversimplifying. How would you ever know when multiplication has pretty much ended and fermentation has pretty much begun? And how would you keep the yeast from fermenting the sugars?

There are two mentalities with when to pitch a starter. I think what you're describing is pitching the starter at high krausen. The other way is to wait for fermentation to finish, let the yeast flocculate out, decant the liquid, and pitch the yeast slurry. I prefer the latter, that way I'm not pitching a bunch of nasty starter liquid into my beer.

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Great rebuttal!

All I will add is that I have ptiched both at high kreausen, and chilled and decanted, and cannot tell a difference in the final product.

If you are pitching a 1-2 liter starter, wort and all into 5 gallons of beer the flavor impact will be negligeable. In addition, many of the undesireable flavors that may have been produced in the starter may be significantly reduced by the yeast post-fermentation. If your starter is kept within the recommended temperature range, and you use an extended primary fermentation, many if not all of the off flavors that may have been added to the 5 gallons of wort will be diluted, and removed to undetectable levels.

Either method makes great beer.