So I've been brewing for a little over a year. mostly your standard 5 gallon batches. Occasionally i do a smaller batch between 1 and 2.5 gallons, and never with a gravity over 1.060. So my question is, if a pack of liquid yeast is good for 5 gallons with a gravity below 1.060, could i pitch half a pack of yeast into a 2.5 gallon batch with a gravity below 1.060?
If you believe the first part of that question, then you can believe the second part, because it's the same rate (assuming a constant gravity and particular viable cell count actually in the pack). But a one-size-fits-all recommendation like one pack per 5 gallons for gravity below 1.060 ignores several things that ought to determine the rate: - the specific OG of the wort (is it 1.059, or 1.040, or ???) - the age of the yeast - beer style - yeast strain - your goals/preferences Calculators like Mr. Malty or Yeast Calc can be your friend here, as can experience when it comes to styles/strains/preferences. And if you pick a pitch rate in cells per milliliter per degrees plato, you can do a lot better than one-size-fits-all.
You could but what are you going to do with the 'leftover' half? If it was me I would just pitch the entire package of liquid yeast; it would be my guess it won't hurt anything here (unless to you are looking for increased esters, etc.). Cheers!
I'll check out those calculators. Is it saft I'll check out those calculators. Is it safe to assume that the package of yeast will tell me how many cells it should contain per millimeter? lastly, I'll probably be making a starter to boost yeast growth should i use a half a pack
The package should tell you how many viable cells it contained when new. Standard White Labs and Wyeast packs start with about 100B cells. Cells per milliliter of the yeast slurry itself isn't really relevant...the total number of cells is relevant. Where the "per milliliter (per degree plato)" comes in is the volume and gravity of the wort you'll be pitching the yeast into. The purpose of a starter is to increase the cell count. Making a starter from only half the pack would be counterproductive (and expensive). Use the whole pack and make a smaller starter (per your calculator of choice).
