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Help me understand the Yeast requirement/starter page


Mar 19, 2018
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I am new to the program and have yet to pull the pin on my first all grain batch.  But before I can do that I need to nail down the last issue I have.

I have a recipe and have scaled it down to a 11 L batch.  In the design page it has me listed for a half package of Wyeast 1084.  Can you do a half pack?  Are you required to do a starter?

Selecting the starter page really doesn't help me understand my requirements.

I would greatly appreciate anyone taking pity on the new guy. 

I thank you in advance.

Greetings, FEaereBrew. You do NOT have to make a starter. For a standard 20 liter batch a package of liquid yeast may not be enough, so it is recommended to make a starter to increase the number of yeast cells you pitch. If you are making a smaller batch then you can pitch the whole package with no starter, or you can pitch part of it if you wish. It depends on the beer you are making and the age of your yeast packet. BeerSmith uses a default pitch rate (changeable via Options->Yeast Starter) of 0.75 million cells/(ml-Plato) for ale, 1.5 for lager and 1.0 for "hybrid " beer. Many other sites recommend 0.75 for ale with Original Gravities less than 1.060 and 1.0 for ales with Orignial Gravities above that. If you have a brand-new package of yeast with 100 billion cells and a starting gravity of 1.040 (=10 degrees Plato) in 11 liters then your pitching rate would be 10^11 cells/(11000 ml*10 Plato)=0.91 million cells/ml-Plato, which is plenty. If your yeast have degraded until they only have 85% viability and your OG is 1.055 (13.6 Plato) then your pitching rate would be 0.57 and that is on the low side so you definitely want to pitch it all.

Look at your gravity and the number of viable yeast cells that BeerSmith predicts based on the age of your packet and decide if you want to pitch all of it or less, but I would guess that you probably want to pitch it all. Unless your  yeast is very old and your beer is very high gravity you should not need to make a starter.

You might enter the production date of the yeast packet along with the OG and volume going into the fermenter to estimate the cell count and the number of recommended cells. Aside from that, the procedure of breaking the inner pack and allowing the packet to swell up does a good job of waking the yeast up.

Unless you're brewing a very big beer, a smack pack that isn't dated should do just fine for your 11 liter batch. Be sure to aerate the wort as best you can, even if that means just shaking the fermenter for a few minutes. Many of us made some good beer before we ever even heard of making a starter or aeration.

I wouldn't split a smackpack unless you are sure what you pitch is adequate. Under pitching is much more likely to cause fermentation problems than over pitching. Until you're ready to overbuild a starter and split off some for a future batch, you're better off just pitching the whole packet.

I greatly appreciate the time and level of detail you went into to answer my question.  I do need to become better educated on the math that is required.