How long does everyone typically let a starter go for before pitching? I’ve usually waited a day and try to pitch than the krausen is up but was thinking about pitching one around hour 14 tonight.
Depends on the size of the starter and the style I’m brewing. For your average ale, I will pitch at high krausen, which for me is around 18 hours.
For lagers and larger ale starters, I’ll step them up and ferment them all the way out, crash in the fridge, decant the wort and pitch the yeast.
Pitching at 14 hours to me seems a little short. How long before you starter got going?
It’s a one liner starter of WLP002 thats been showing some life (made it around 9:30am this morning). Basically I’m debating if I should pitch it around midnight tonight or let the wort sit in a corny overnight and pitch in the morning (so 22 hour starter/delay pitch or 14hr starter pitched as soon as the wort hits 70f).
The beer is pretty light, 1.033 ordinary bitter.
I give it about 36 hours on a stir plate, then crash, decant and pitch. So maybe 3 days total.
I typically make my starter wort on Saturday morning while drinking coffee (I use the side burner on our grill on the back porch). I’ll let it cool and then pitch the yeast (normally wort will be cool around the same time that smack packs are ready). So… roughly sometime Saturday mid-afternoon. Sunday is then brew day, so that process is typically wrapped up around 5pm. I guess that means a little over 24 hours for 2 smack packs into ~2.5L of wort for a 10 gallon batch.
I’d wait until morning, but that’s me. For a 1.033 beer though, the vial alone would probably have been enough. So I guess 14 hours is may be ok…basically waking the yeast up. 5 gallon batch right?
Yeah, with such a low OG the vial probably would’ve been plenty (based on how old it is). As is, I think you would be fine to pitch once you see some activity in the starter even without crashing.
Yea, the vial would probably be fine with the gravity. I figured I’d error on the side of a starter since beer smith suggested more cells and I hear that a heartier pitch with 002 should reduce esters and diacytel
Esters, maybe. I’d still bump up the temps and rouse the yeast at the end to insure against diacetyl. When 002 is done it drops like a stone. If there’s diacetyl left at that point it may stick around.
You will get differing opinions on this. I either pitch the whole starter at high krausen or chill the starter at high krausen then decant the beer then pitch. Search the forum and you will find some extensive threads on this in the past year or so.
I recently pitched 002 into a mild of similar gravity to yours. A short-on-time starter is fine. I’d rouse the yeast once a day for the first three days because, as someone already mentioned, 002 drops out really easily. Makes a hell of a clear (and tasty) beer but you’ve got to goose it along a bit.
Appreciate all the advice - I ended up waiting until this morning and I’m crashing the yeast out now then will decant and pitch. My plan was to throw the whole starter in but I decided I should have more headspace in the keg.
I’m pretty excited to try out two new things with this batch, fermenting in a corny and a corny to corny transfer into the serving keg.
I think brulosophy.com recently did an experiment on this, and it showed no statistical significance either way. Worth checking out to get you comfortable with whatever approach you land on.
Fourteen hours of incubation time is more than long enough for a 1L starter that was inoculated with a vial of White Labs yeast that is less than 4 months old. Most strains take less than 6 hours to exit the lag phase (many will exit the lag phase in less than 3 hours). The average White Labs vial contains 50 billion viable yeast cells when pitched (100 billion at time of packaging). Yeast cells divide approximately every 90 minutes after the lag phase has been exited, which means that the culture will contain approximately 100 billion cells 90 minutes after exiting the lag phase. A 1L starter that was pitched with 50 billion viable cells will reach maximum cell density approximately 3 hours after exiting the lag phase, or roughly 9 hours total for most yeast strains. Given enough O2, carbon, physical room to grow, the time to reach 400 billion cells is approximately 10.5 hours, and the time to reach 800 billion cells is approximately 12 hours.
A key point to remember is that the yeast biomass grows exponentially, not linearly. The growth rate is 2n, where n equals the number of minutes that have elapsed since exiting the lag phase divided by 90. The equation for calculating the approximate number of cells at any point during incubation given an initial cell count is:
cell_count_at_time_n = initial_cell_count * 2(elapsed_time_since_exiting_the_lag_period_in_minutes / 90)
The equation shown above is bounded by O2, carbon, and media volume.
One last thing, starters should be incubated at room temperature.
If the goal is to crash or pitch at max cell density without letting it get too far past that, how can you tell it’s there when the starter doesn’t necessarily form a krausen?
Should you just assume that as soon as you have activity that they are past the lag phase, then calculate the time from there to max cell density based on the estimate of starting cells and the size of the starter?
Is it really bad if you crash or pitch prior to reaching max cell density?
Is it better to crash a little too soon or a little too late?
Thanks!
If you are not seeing a krausen start to form within 12 hours after inoculation with a Saccharomyces strain, then you doing something wrong. Failure to see at least the start of a krausen within 12 hours after inoculation is usually a sign of a low viability culture, low dissolved O2, not enough carbon or too much carbon (sugar is carbon bound to water), and/or the incubation temperature is too low. Most of the time, long periods of time between inoculation and the onset of high krausen with a Saccharomyces strain is the result of low culture viability, which can be a problem during the summer months on the East Coast. Liquid yeast cultures do not like being shipped in the summer heat.
Are you making your 1L starters using 100 grams of DME? Are you incubating your starters at between 22C (70F) and 25C (77F)? How are you obtaining your cultures? Are they stored in a refrigerator until use? How are you aerating your starters? If using a Wyeast smack pack, are you waiting until the package swells completely before inoculating your starter?
Finally, you do not need to crash a starter. The wort from a non-stressed starter does not taste or smell foul. All you need to do is to compensate for the dilution by boiling the wort down approximately 0.002 below your target gravity when pitching a 1L starter into a 19L (5-gallon) batch.
If a pack of yeast is suspected of having low viability, what’s the best approach? Make a smaller starter and step it up once or twice?
Yes
I used a brand new (iirc, 2 to 3 weeks old by manufacturing date) Wyeast smack pack obtained at my LHBS the same day I made the starter. I smacked it as soon as I got home and it started to swell within the hour. It was fully swollen by the time I pitched it into the starter about 3 hours later.
My starter was 100 grams light pilsen DME brought to 1100 ml in distilled water, then boiled back down to 1000 ml and cooled to 70o F and oxygenated with pure O2 for 10 seconds before pitching. I used a 3 piece airlock on the flask. (2-liter flask as marked but it holds more like 3.5 liters and has a fairly large surface are when the volume inside is only 1 liter.) The room temp was 71o maintained by air conditioning.
It had signs of activity within a few hours. I could see the white-ish layer of yeast near the top of the liquid, started getting airlock activity, etc. Within 5 hours it had a very active airlock, a thin layer of yeast on the surface but only covering about 50%, and it smelled great. I was expecting a krausen to form in the near future.
It continued to actively ferment for several more hours but no real krausen ever formed. At hour 10 I noticed a nice white layer of yeast start to form at the bottom of the flask. At hour 11 I decided to crash assuming it had progressed beyond the height of activity. Funny thing is the next morning in the fridge there was a “krausen like” formation on top of about an 1/8" covering 100% of the surface. When I put it in the fridge the top just had a wispy yeast layer on it.
It ended up forming a layer of yeast between 1/8" to 1/4" on the bottom of the flask. I decanted, warmed, and pitched a couple of days later and had one of the quickest blast offs that I’ve experienced. (Only have about 50 batches of experience so far, but still…) Everything about the fermentation seems to be very healthy so far.
From all the clues, I collected a good quantity of very healthy yeast. Just for some reason it didn’t form a krausen. I watched it fairly closely, at least every 30 minutes putting an eyeball on it.
The only reason I want to maintain the practice of crashing is due to being nervous about timing it to be able to pitch into wort at high krausen. Since the timing of when it might be ready can vary, unless it makes a huge difference in performance, I would rather have it ready a few days ahead of time. Is that bad?
This is great info, thanks Mark.