Wyeast Liquid Yeast Pitch Question

[andre_0101]

Hello!

I am a relatively new home brewer making small 1 gallon BIAB batches. I just recently started trying out liquid yeast instead of dry yeast in my brews.

My question is this. Wyeast says the following on their website regarding their smackpacks:

"
The Wyeast Activator Smack Pack is designed to directly inoculate 5 gallons (19 L) of standard ale wort (O.G. <1.060) at the correct pitch rate for reliable, consistent brewing.
"

However if I go to a yeast pitch rate calculator, Yeast Calculator for example, and I calculate the pitch rate for a 5 gallon, 1.050 brew it tells me I need 176 billion yeast cells.

My confusion point is the Wyeast smack packs contain 100 billion yeas cells and according to them I should be able to directly pitch their pack without a starter. But according to the yeast calculator I would be 76 billion cells short...

I know technically I could create a yeast starter but this is more to understand the discrepancy between the two scenarios and also so I can figure out how much liquid yeast I should be adding to 1 gallon batch's of medium to high gravity brews. I am thinking half a pack to a full pack for each gravity level respectively should have me covered but not sure.

Any input would be greatly appreciated.
Thank you!

 

[GoodTruble]

Your math is not wrong. It is a noted issue among home brewers. Omega increased its package size/yeast count to be closer to recommended pitch rate. I just use starters.

 

[lumpher]

If you use 1 pack, it could stress the yeast and end up with off flavors. You need to do either a starter or use 2 packs for 5 gallons. 1/2 a pack with no starter would work for 1 gallon.

 

[andre_0101]

If you use 1 pack, it could stress the yeast and end up with off flavors. You need to do either a starter or use 2 packs for 5 gallons. 1/2 a pack with no starter would work for 1 gallon.

Hi Lumpher,

My one pack/half pack comment was in regards to direct pitching to 1 gallon batches.

The five gallons part was used for the question regarding the difference between what's on the wyeasts pack as relates to their stated suitable direct pitching rate vs calulating that same (or very similar) pitch rate( 5 gallons at 1.050) through a online pitch calculator. The online yeast calculator says I am short by approximately 76 billion yeast cells yet wyeast says I should be good to direct pitch.

 

[lumpher]

Yep, and I was more or less trying to address both. Their claim that 1 pack will do 5 gallons is not right. For 5 gallons, you need 2 packs or do a starter. There are specific situations where you might use 1 pack for 5 gallons to cause a certain flavor profile, but that's down the road a bit for you, most likely.
For your 1 gallon batches, you will be ok to just use 1/2 a pack with no starter.
Maybe this clears up what I'm trying to say a little bit.

 

[McMullan]

You'll get a better fermentation if you make a starter, to pitch fresh, viable yeast cells. It's good practice to make one, because we don't know the condition of the yeast cells. If I were making a 1 gallon batch I'd make a 0.5L starter with about 1/4 of the Wyeast pack/slurry. Save the rest in a small sterilised vial. Unless you use a microscope to count yeast cells and assess viability, ignore online calculators. It's better to determine empirically what works best for you than adopting a mysterious online belief system re yeast starters and pitching rates. Simplify things down to 'small', 'medium', 'large' starters. It doesn't need to be complicated at all. A starter to confirm yeast viability and produce more cells; pitch fresh into aerated wort; done. Liquid yeast 101.

If you want to take things to the next level, repitch the yeast slurry from the first fermentation/generation. Again, no calculators needed. It's 'bucket biology'. The bigger the pitch the better fermentation. The chances of over pitching are vanishingly small.

 

[bwible]

I pretty much do 3 gallon batches of everything now, so it works for me.

 

[andre_0101]

I pretty much do 3 gallon batches of everything now, so it works for me.

To confirm, the Wyeast direct pitch works for you without a starter for your 3 gallon batches?

 

[IslandLizard]

But according to the yeast calculator I would be 76 billion cells short...

It's likely worse, she could well be another 30-60 billion cells shorter than that, due to age, and then some due to shipping, especially in hot weather, etc.

Unless you picked up a truly fresh pack at the WYeast plant, packaged yesterday, not shipped, there are far less than 100 billion viable cells in that smackpack. Most LHBS yeast is 3-4 months old already. Put the manufacturing date (6 months before the best-by-date) in your yeast calculator too, for a better estimate. Therefore making starters is not only recommended, it's encouraged, and almost always necessary, even if you pitched a whole pack into 3 gallons of medium gravity wort.

I use this yeast calculator: Homebrew Dad's Online Yeast Starter Calculator

Most of these yeast calcs aim for industry standard optimal pitches. You probably could get away with pitching half those cells and turn out just as excellent beer, all other factors being equal.

But... we merely use estimates, so a 50% margin of error can be expected, and it's usually better to err toward overpitching by some amount rather than underpitching by the same amount.

Now yeast vitality is actually much more important than gross cell count (or estimates thereof). So if you make a 1 - 1.5 liter (vitality) starter, and pitch that, you'll be a lot closer to that target than pitching 2 packs of unknown vitality (due to age, shipping, etc.) directly from the homebrew store.

Look up "shaken-not-stirred" (s-n-s) starters.
Easy to make, just use a gallon jug with a screw cap.

 

[bwible]

To confirm, the Wyeast direct pitch works for you without a starter for your 3 gallon batches?

Thats what I normally do. I typically always re-use yeast several times. And the first batch I will brew is usually something lower gravity. I brew weak to strong, light to dark. Same way judges judge.

- Except for lagers. I make a starter for lagers.

 

[Bobby_M]

It's all based on the age of the pack. Other than the White Labs "purepitch", the viability of a pack drops substantially with time. Use the "calculate viability" checkbox in the calculators.

 

[jdauria]

I think Wyeast and White Labs both have used the 1 pack for <1.060 beers as a marketing thing to not turn off people who do not make starters from having to buy 2 packs or more. I mean if I was a new brewer and had to pay $20 for two packs of their yeast vs $6 for a pack of a competitor's dry yeast, I would be buying the dry. Even if a LHBS got the yeast from the labs the day after it was packaged, it still does not have enough cells for a 5 gallon batch, let alone packs that are older. That's why I am a proponent of Imperial and Omega yeasts, as they are 200 billion cells, which still may not be enough in some cases, but a lot closer. I think White Labs may be coming out with 200 billion cells packages too, they have a tease on Instagram about "Pure Pitch 2.0", picture is all shadows but it looks like a larger, almost bottle like container.

 

[mashpaddled]

What I do with those small batches is just pitch what I need in the fermentation vessel and put the rest in a mason jar with a small amount of starter wort. Let the mason jar sit with the lid lose for a few days and then seal it up and put it in the fridge until you need it. If you're worried about the pitch rate, make a small starter before you pitch it. You can even keep some of the original pitch in the mason jar and repeat the process so you always have a clean culture.

 

[Bobby_M]

I think Wyeast and White Labs both have used the 1 pack for <1.060 beers as a marketing thing to not turn off people who do not make starters from having to buy 2 packs or more. I mean if I was a new brewer and had to pay $20 for two packs of their yeast vs $6 for a pack of a competitor's dry yeast, I would be buying the dry. Even if a LHBS got the yeast from the labs the day after it was packaged, it still does not have enough cells for a 5 gallon batch, let alone packs that are older. That's why I am a proponent of Imperial and Omega yeasts, as they are 200 billion cells, which still may not be enough in some cases, but a lot closer. I think White Labs may be coming out with 200 billion cells packages too, they have a tease on Instagram about "Pure Pitch 2.0", picture is all shadows but it looks like a larger, almost bottle like container.

I've speculated the same on wyeast and white labs before. If the packs were literally one day old, I can see direct pitching in sub 1.060 and "getting by".

Omega has moved up to the same pitch rate as Imperial about a year ago, approximately 200B cells. Both of them are still subject to aging out of viability. The White Labs Purepitch is a pretty significant upgrade in long term shelf life. Even though you start with 200B cells, the viability is down to 12% or 24B cells in 4 months. The same 4mo pack of purepitch whitelabs is 85% viable for 85B cells. Essentially age matters for all yeast labs except for WL.

The Purepitch 2.0 starts at 200B cells and is currently rolled out for WLP001 only and will grow from there. What that means to me as a brewer is that I will only be buying WL if they have the strain I want.

Omega continues to be quite innovative on strain variations so I won't be quitting them anytime soon.

 

[KeizerBrewr]

Most all liquid yeast offerings are not the promised cell count is by the time you get to brew day. That is why I got into making starters after my third batch of beer I ever produced and it really helped with decreased/minimal lag phase, stronger fermentation and more consistent beers. On top of that, I would over build and pour off the excess into a jar to save that slurry for later for future starters, this helped ensure healthy, happy yeast. My yeast bank is of four strains, WY1388(Belgian Strong), WY1968(London ESB/Fullers), WY2565(Kölsch) and WY2633(Octoberfest Blend). I use the first three often with the lager strain late winter/early spring, but all four see near consistent use. I will likely be increasing the bank size to five since I need a kveik strain in there.

 

[andre_0101]

Thank you everybody for the feedback, incredibly insightful! Sounds like at the end of the day a starter is the way to go to ensure you have what you need and take the unknown out of the equation. Thank you!

 

[KeizerBrewr]

THIS is the stir plate I use and works great! Glad everyone could help you out, feel free to reach out if you have any questions.