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Yeast Starter Questions on Process, etc

I’ve read all of the posts and various articles along with the book on Yeast and still have some questions. I recently purchased a stir plate and a couple of Erlenmeyer flasks for yeast propagation using a starter. I had a package of some old Omega yeast (7 months old) and figured I’d use it to practice creating a yeast starter. So far, 18 hours in, the experiment is going as I’ve come to understand from my research. My questions are as follows;

  1. After ~24 hours do you place the starter in the frig so that it will floc to the bottom?

  2. Second part of question 1, do you then pour off (decant in beer lingo) the beer off the top before mixing a slurry to pitch into the wort?

  3. How long will the yeast last in this state in the frig? I’d like to make the starter a few days before my planned brew day. I’d also like to save the yeast I create from this experiment for future use (have a brew planned for next week).

  4. Comments on adding hops? I’ve read that adding hops “may” reduce chances of infections, etc. due to their inherent antimicrobial properties. Personally, I don’t see what if any gains from this if you follow good sanitation practices.

  5. I plan on using an external magnet to hold/remove the stir bar from the flask. Any other preferred methods?

I’m sure we all have our opinions on this subject and expect to hear from various camps on “how to”. Thanks in advance!

Q#1. If you are propagating to save some yeast, YES.
Q#2. NO. I’ll swirl it so its all in suspension. Even swirl a time or two as I pitch it into the wort.
Q#3. I’ve had viable yeast under a beer cap up to a year.
I take my yeast out on Friday night. Saturday make a starter, cool it, put the yeast and starter together and shake the living bejesus into it… Many times until it’s very foamy… Give it a shake when you walk by it… Sunday is brew day and the yeast is happily ready.
Q#4 I use a good hoppy brew for my “beer cap”. There are some naturally occurring bugs floating in the air that could infect even the sterilest of worts/yeasts.
Q#5. I don’t use that method anymore.

Ok, @sneezles61

Q#3. I’ve had viable yeast under a beer cap up to a year.
I take my yeast out on Friday night. Saturday make a starter, cool it, put the yeast and starter together
and shake the living bejesus into it… Many times until it’s very foamy… Give it a shake when you walk by it… Sunday is brew day and the yeast is happily ready.

Please clarify. What do you mean by put the yeast and starter together? I thought the starter contained all the yeast for the brew.

Q#5. I don’t use that method anymore.

How do you remove the stir bar?


  1. 24 hours isn’t a magic number. I wait until the yeast is done growing. Sometimes I’ll time the starter, as best I can, to pitch into a batch of wort as the starter peaks. Other times, I’ll chill in the refrig and then decant.
  2. Yes, if I have chilled it. If you decant, leave a little beer on top of the yeast, don’t pour it all off.
  3. I’ve never gone beyond a few days, but I’ve heard of others going longer,
  4. Never thought about adding hops. Never had a reason to.
  5. Yes, I use an external magnet to remove the stir magnet before pitching. But be careful with it - see this old post of mine Magnet stronger than glass

I call the mini wort a starter… and when it’s mixed together it’s called a starter too… Broad brush stroke that covers that whole process…
I no longer have a stir plate and stir bars… I use the " shaken method"…


I don’t make massive starters anymore. Mostly 1L for 5 gal, shaken not stirred, which I start the night before brew day and try to pitch at High krausen. So no chilling, decanting or much advance prep needed.

These kind of starters are generally made with fairly fresh yeast slurry that I’ve collected so I figure they’re around 2-3 B yeast sells per ml. So typically 2-3 x more yeast than you’d have in a smack pack.

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I make a starter a 24 hours before brewing. I pour off some into a 4oz mason jar to store in the fridge to save for the next time. The rest I pitch into my wort. I don’t use the stir plate if it’s warm in the house because mine adds a bit heat.
I don’t worry about the stir magnet. I just pour carefully and retrieve when empty.

Here is a classic link to shaken not stirred starters. Highly recommended.


@Steve Yes, I read that post and saw the pic a few days ago. That was pretty wild.

I had read about the stir plate adding heat. I made a few measurements while it was stirring and can’t say I saw any change in the temp on the plate surface. I did notice some change in temp on the flask, but attributed that to the mini-fermentation going on in the starter.

Me do make a starter. Few days before brewing. Leave it 30 hours on the plate. Than transfer to mason jar. Put in fridge. On brew day take out pour some out of mason jar. Think they call it decant. Let yeast warm up. Swirl. Here and there. Time to pitch. Got few starters allways ready in my fridge. Some. 5 weeks. Or longer old. Have not seen any issues so far


Mine is an old enamel baked lab stir plate. Could be it’s age and construction that makes it warm up.

Same here shake method using mason jars. For lagers I’ll make a one gallon starter so obviously pouring the beer off that as far as a standard litre/quart starter sometimes I do sometimes not. I’ve used some pretty old yeast in emergency situations but the fresher is better. I’m kinda a spur of the moment brewer so I’ll start some and leave in the fridge it’s fine. I don’t make starters slury but have been known to add a little wort to wake it up and pitch at high krausen

I’m coaching a friend, long distance, how to use the mason jar technique to harvest the Oslo yeast from a bottle I sent him.

Tossing a few hop pellets in your starter is kind of an old fashion back up plan to keep it safe from bugs. I think with sanitizers like Starsan the likelihood of and infection is much less than when we used bleach and rinsed everything.

However that small amount of hops is so cheap and you can just use a few pellets from the upcoming brew, why not? I have done starters with and without and have never (knocking on wood) had a problem either way.

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If that actually worked we would never have to worry about our beer getting infected right? I’m dumping my starsan.


When you think about it we just wash and rinse our dishes with soap and hot water, dry them and put them away. Then just take them out and put food on them. Less contact time of course but we do the same with food storage containers. Sometimes you get mold on stuff in them though :scream:

Bleach worked with glass containers but you would’t want to leave it in contact with plastic for long. The hop pellets in a starter gave you a warm fuzzy feeling that everything would be alright.

I’ve taken to just increasing my starting wort volume by roughly 1/4-1/2 gal, boiling 10 mins, then taking just over 1000 ml in my flask, chilling in my sink while I boil down to starting volume, pitch liquid yeast then tossing on my stirplate low and slow for 8 hours or so. Then I pitch the whole thing in the fermenter before I go to bed.


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@wilcolandzaat That sounds exactly like what I’d like to do. It seems the liquid yeasts at my LHBS are always a month or more old. I use BeerSmith and it usually tells me to pitch 2 pouches to hit the cell count required. I tired that on an earlier brew and it performed well. I experimented with harvesting some yeast, etc. This recent procurement of a stir plate and flask gave me the opportunity to experiment with it and have to say it was nice (with the exception of the stir bar noise :smile: The 7 month old yeast took off (which I have since stored in a boiled/sanitized mason jar).
I’m going to be using a pack of Loki by Imperial for this next brew (a repeat of an earlier ale). It’s a kviek and is dated 12/23/2019. Using the BeerSmith starter tool, I plan on making a 1000 ml starter on Monday, brew on Tuesday and pitch it late Tuesday afternoon/early evening. I could even brew on Wednesday, but the wife and grandson are at school Tuesday so I have the place to myself (along with Carly the Corgi our 6 month old puppy).

Your logic is sound. I have not used Loki but aren’t Imperial yeasts 200 billion cells per pouch? If so make sure you account for that in your starter caluculations. Good luck.

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