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

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

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

IslandLizard

It's likely worse than that, 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 factory 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 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 much more important than actual 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 directly from the store.
Look up "shaken-not-stirred" (s-n-s) starters.
Easy to make, just use a gallon jug with a screw cap.

bwible

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.