I haven’t brewed in about six months and now white labs has this new pure pitch which they say is twice the amount of yeast and it doesn’t need a starter. I’ve always done a starter and still inclined to do one but I don’t want to over pitch. What are people doing with these? Thanks.
There are 2 main things to look at…
Viability of the yeast - the fresher the better
Starting gravity, and batch size - I like using brewers friend pitch rate calculator… https://www.brewersfriend.com/yeast-pitch-rate-and-starter-calculator/
My train of thought is that it is easy to under pitch and difficult to over pitch. I like to err on the side of doing a starter - I aim to give my yeast the best head start it can get.
but you can certainly get away without doing a yeast starter
I haven’t used one yet, but I will be doing so in a couple of days. I plan to directly pitch the whole package, which has a “best by” date of mid-September. I would only make a starter if the yeast was nearing or past its expiration date, or if the beer had a very high OG.
I looked at the QC numbers for my package and it was 2.15 billion cells per milliliter. Multiplied that times 70 mL which is what is in the package. And then plugged it into my used calculator for a starter that I usually use. Said it was 60 days old and 53% viable and definitely needed a starter. So unless its viability is somehow different than the prior pure pitch, guess I’ll be doing a starter .
The viability at 60 days should be much higher than 53%, even for the previous generation of Pure Pitch packaging. White Labs doesn’t give much quantitative information on viability vs time, but Brad Smith supposedly got aging information from them for their Pure Pitch packaging and incorporated it into BeerSmith 3. At 60 days BeerSmith estimates 77% viability. BeerSmith estimates my yeast’s viability at 60% even after 130 days.
If the yeast is only a month old, I wouldn’t use a starter. If it’s three months old, I would start thinking about doing a starter. If it’s four or five months old, yes definitely I would like a starter. Pretty much the same as I ever did with the previous packaging. Old yeast is old yeast, at least when liquid. (Dry yeast is a different beast altogether, no starters needed, ever. Which is why I use dry almost all the time now.)
I just used WLP001 in the new Pure Pitch packaging yesterday in my Brown Ale. I made a starter since this was an 11 gallon batch. Before making the starter, I used the White Labs pitch calculator to determine that the starter volume agreed with what Beer Smith was telling me for 100B cells in the package. I had good agreement and made a 3.5 liter starter. Had active fermentation in about 6 hours. I always err on the side of caution here by making a starter due to the fact that there is shipping involved to get the yeast from White Labs to my LHBS. The yeast best by date was 11/4/2023 so it was really fresh.
FWIW, I like the new Pure Pitch packaging much better than the last iteration.
FWIW, I’ve reached the conclusion that pitching active yeast makes much more difference than cell count does. For that reason, I say make a starter.
I used them in my last 4 beers without a starter and have been happy with the performance. They’ve all shown visible signs of fermentation pretty quickly and have attenuated fully. For reference, these were 5.5 gallon batches of moderate gravity ales, and 3 out of the 4 beers were pitched with STA1 positive stains. I do tend to get pretty fresh pouches, maybe 4-6 weeks old, being in Southern California.
Based purely on numbers, it’s a slight underpitch. I think making a starter with liquid yeast is always good but haven’t been able to bring myself to do it recently.
True! But making sure that I don’t over-pitch is why I use the calculator. I have always heard that slightly under-pitching is better than over-pitching and I always have really good results with that method.
I make SNS starters so I don’t have to worry about cell count
I thought it was really hard, impossible, for homebrewers to over pitch?
Here is how to overpitch: Take a fresh package of an ale yeast with 150 - 200 billion cells and make a 2 liter starter with it (a 1 liter starter would be too small for that number of cells). Pitch that whole 2 liter starter into 5 gallons of wort of OG 1.035. You would have something like 5 times the number of yeast cells you need. I think that would count as an overpitch.
Maybe. Keith recently posted info indicating that a large amount of yeast into a small amount of wort doesn’t result in significant cell growth.
Exactly. There is no need for any more cells, so no growth. Many of the flavor compounds are generated during the growth phase, so they will be lacking.
That’s the theory and it’s what I found in practice.
“Here is how to overpitch: Take a fresh package of an ale yeast with 150 - 200 billion cells and make a 2 liter starter with it (a 1 liter starter would be too small for that number of cells). Pitch that whole 2 liter starter into 5 gallons of wort of OG 1.035. You would have something like 5 times the number of yeast cells you need. I think that would count as an overpitch.”
This is theoretical. Correct? Similar to “If we stop our car by crashing into a wall this is not good for the car or us.”
My question, as homebrewers, whom does such a HUGE step up?
Lots of people do.
“Lots of people do.”
How is this known?