Usefulness of yeast starter

Hello homebrewers,

I've been brewing for a while now and I recently decided to harvest my yeast. Since everytime I saw someone using harvested yeast, he was using a starter, I decided to do as so. I had never use a starter before and frankly, I don't really know why I should. I've been brewing several beers, a lot over 1.070 OG and even over 1.090 OG and I never had a problem. My beers always turned out good and I could see the krausen appear after 24 hours or less.

So, I know a lot of you use starter everytime, but is there a reason other than :"I just want to make sure that nothing goes wrong" ?

BTW, I normally use white labs yeast that I buy at my local homebrew store.

Putting a small number of yeast into a large volume of wort causes the yeast to be stressed out. There are far too many sugars for their liking and they go crazy trying to reproduce. Often times this works out fine in the end, but you run the risk of off flavors (depending on style) or a slow-starting, perhaps stalled beer. The off flavors are esters produced during reproduction and while the yeast try to clean these up, if they are stressed and in the presence of a ton of alcohol, they don't always get the job done.

Again, you may never have a problem, but chances are it will bite you at some point.

Start thinking in terms of cell count.

I have X gallons of beer at 1.0XX gravity, therefore I need X billion number of cells.

I estimate my harvested yeast or yeast vial has Y billion cells therefore I need to build a starter to grow Y billion cells to X billion cells


yeastcalc.com will do all the math for you. Shoot for +/- 20% recommended cell count

Yeah, worst case just make a 1L starter for every vial of liquid yeast. If your gravity get's into the higher range (50's+), make a 2L starter.

Of course, you can also take half of your beer and pitch into it, then after a few days when it's krausening, add the second half.

Both of these suggestions are an "inexact" way to "get close" if you don't want to bother with specifics.

I make starters for all my beer regardless of the gravity and it is for several reasons:

1. To ensure the overall viability of the yeast
2. To ensure proper pitch rate for the beer in question
3. To reduce lag time
4. To ensure my yeast is not in a stressed condition to perform its job

It is true that starters can be considered not necessary and that your beer will still ferment and turn out well however, for the above reasons it is beneficial to make them.

In using starters I see most of my fermentations begin in earnest within 8 hours or less. The reason for this is due to using the proper pitch rate for the given beer. Lag time is when the yeast begin consuming oxygen to replicate and multiply so by pitching more yeast you reduce this time considerably.

Here is a practical example: You have a construction project to complete and have the option of having 2 men on site daily to complete the project or you can have a crew of 6 perform the same job. The crew of two will get the job done but it will take longer and most likely the labor will endure some stress due to the size of the project at hand. The crew of 6 will perform the job quicker and there will be less stress on each laborer because there are more hands on the project to aid in its completion. The project will be done in a more efficient manner and with a greater chance of less problems occurring.

Stressed yeast have a greater potential to produce off flavors in your beer and the chances of experiencing a stuck or stalled fermentation are greater than had a starter been used.

IMVHO and experience it is a very beneficial addition to your process if you continue to use liquid strains of yeast regardless of how fresh the package is.

Make beer is easy. Making good beer takes some effort. Making great beer is difficult and requires attention to many factors. One of the most important factors is the appropriate environment for the intended result based on the yeast strain and beer style/target flavor. This means pitching healthy yeast and the right amount. A good starter ensures that your yeast are at their peak viability and best approximated population at pitching time. You could think it's about making sure nothing goes wrong, but I like to think about it in terms of making sure everything goes great. Underpitching can cause esters or other off flavors that are undesirable. You may have achieved good results with your previous method, but I think you would be surprised to do a side-by-side comparison with the same wort fermented with a fresh starter.

Edit: A little slow on the trigger, but I think you are probably seeing a bit of a consensus here.

Lastly, if you harvest your yeast cake into 4 jars (after swishing it around and mixing it up well), each one is plenty to pitch into the average 5g batch without a starter. Refrigerate them, then just let them warm to room temp (loosen the lid a bit) for a few hours on brew day, then shake and pitch.

As far as i understand you don't need a starter if you harvest enough yeast. Correct me if I'm wrong but the Mr Malty calculator gives an amount of harvested yeast and does mention a starter. This is for washed yeast though.
As others have said you could pitch on top of an whole yeast cake, especially if you are doing high grav.

Just FYI, lab testing shows that the number of yeast cells in 1ml of yeast slurry harvested from a previous batch is around 1 billion cells/ml.

So for 1 cup of slurry you may have 200 - 250 billion cells. This is plenty of yeast for 5 gallon batches but not quite enough for 10-11 gallon batches. I usually harvest about 2 cups of clean slurry from my fermenters and then put 1 cup in each mason jar. If I pitch 1 cup of slurry to a 2.0 liter starter it creates about perfect yeast counts for my 11 gallon batches of session ales.

Making a starter not only allows you to about double the yeast count but it also gets them active and ready to go into your wort!

Thanks guys, I liked the answers about the off flavor esters, that make sense. Although I'd like to perform a test where I make a high OG beer in 2 different fermenters. One with normal yeast, the other one with a starter. I wonder if the taste will be that much different.

I should have done my master on that!

Jayhem said:

Just FYI, lab testing shows that the number of yeast cells in 1ml of yeast slurry harvested from a previous batch is around 1 billion cells/ml.

Click to expand...

User WoodlandBrew on here has mentioned that 2 or even 3b/ml is not uncommon in slurry. Even the calculators will show that slurries of relatively thick yeast (settled sufficiently), even with 20% non-yeast percentage have over 2b cells/ml. My cakes are probably about 300-400ML. Based on this, I can split that in 4 and pitch each directly into 5g of beer pretty confidently.

There have also been some tests showing that viability isn't as drastically reduced over time stored as previously thought. I'm not a scientist, so this is second-hand, but I hope we'll get some new info from such studies.

Really good thread, guys! good info!
I never thought of pitching into half the wort, then adding the rest @ high krausen!
Thanx tre9er!
The consensus is definately to use a starter.
I've just recently began using starters and I wish I had been the whole last year. Previously, I just pitch enough fresh, washed yeast to get it done with no problems at all. But...
Since I've dialed my system to give me an extra gallon of wort due to super high efficiency from over night mashing, I run off a bit of lower gravity wort, boil seperately w/o hops, pitch slurry, and by the time my wort has cooled to temp (no-chill) 12-24hrs later, my starter is ready & happy.
Man, I love this hobby! So many angles!

So on this topic, I would like some commentary on my procedure to save/culture yeast, I will keep the info general:

1) Using WL 400 (belgian) pitching into 1.040 2L starter in E Flask (Starter 1)
2) 24 hours later, shake and pour 1L into sanitized grwler. (Temporary "parent stock" container)
3) Cold crash growler, decant, store sluury in sanitized mason jar for future brew (Parent stock)
4) Add 1L fresh cooled wort to 1L still in E flask, 24 hours, decant and pitch into my 5 gallon fermentor.(Starter 2)

I havent actually done this yet, but am very close (about 1 hour). I figure I can repeat this procedure as requires when I want to use the yeast.

I also figured after doing the first starter would give me 200 billion cells, so splitting would give me 100 billion in storage then doing another starter so back to 200 billion for pitching.

Any thoughts?

tre9er said:

User WoodlandBrew on here has mentioned that 2 or even 3b/ml is not uncommon in slurry. Even the calculators will show that slurries of relatively thick yeast (settled sufficiently), even with 20% non-yeast percentage have over 2b cells/ml. My cakes are probably about 300-400ML. Based on this, I can split that in 4 and pitch each directly into 5g of beer pretty confidently.

There have also been some tests showing that viability isn't as drastically reduced over time stored as previously thought. I'm not a scientist, so this is second-hand, but I hope we'll get some new info from such studies.

Click to expand...

I have read up on the WoodlandBrew blogs...pretty interested work done there. Personally I would rather over pitch than under pitch because I don't like estery beers so I always estimate 1 billion/ml...this also helps me if I use harvested slurry that is a month or 2 old...the viable count is likely closer to 1 billion at that point.

Jayhem said:

I have read up on the WoodlandBrew blogs...pretty interested work done there. Personally I would rather over pitch than under pitch because I don't like estery beers so I always estimate 1 billion/ml...this also helps me if I use harvested slurry that is a month or 2 old...the viable count is likely closer to 1 billion at that point.

Click to expand...

Yeah, he's done some work on viability over time, as well. It seems that we might get better storage from our yeast than we think. I would agree on slightly overpitching when in doubt. I used to just pitch 1/4 cakes in everything.