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You are here: Home --> Forum Home --> Brewing Forum --> Brewing Discussion --> starter duration?

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homebrewdad
Charter Member
Birmingham, AL
2480 Posts


I routinely see people talk about how starters are "done" in 24 hours (or less). And while I completely understand the concept of a vitality starter, I believe that's a different thing as opposed to building up the traditional way to hit a certain cell count.

What I'm wondering is this - how is it that so many people report that starters are/should be done in 24 hours or less?

I have a starter going for this Frankenyeast that is approaching hour 40 on the plate, and currently has at least two inches of krausen on top. A day ago, there was a very small krausen.

I get very similar results across yeast strains.

My procedure:

Boil starter for ~5 minutes in a stainless pot. Cool the pot in the sink via ice bath until the starter wort is 70-75 degrees F.

Sanitize erlenmeyer flask with star san. Drain, leaving some foam behind.

Pour starter into flask.

Add yeast nutrient (1/2 tsp for 2 liters, scaling for starter size).

Add stir bar.

Loosely cover starter with sanitized aluminum foil.

Run starter at a fairly fast spin.

Starter is running in ambient 68 F - 72 F temperatures.

I know that krausen isn't the end all point, but it's a pretty reliable sign of active fermentation. Why do I seldom see a great krausen until the second day or so?




Posted 34 days ago.

KidMoxie
Charter Member
San Elijo Hills, CA
405 Posts


Generally speaking, I believe White et al claim that starters will finish in about 18 hours. I'm sure this assumes a baseline vitality and dosing rate, so low vitality or low pitching rates might extend the duration. However, 24+ hours you're getting into the range where you're actually exhausting the yeast's energy reserves and leaving them "tired" for when you eventually pitch them (this is the same reason they don't tell you to make a starter for dry yeast).




Posted 34 days ago.

KidMoxie
Charter Member
San Elijo Hills, CA
405 Posts


Also, 1/2 tsp of yeast nutrient is the dosing rate for 5 gallons of beer, you really only need a few dashes for a starter.




Posted 34 days ago.

homebrewdad
Charter Member
Birmingham, AL
2480 Posts


Well, the label (Fermax yeast nutrient) says to use 1 tsp per gallon, hence my usage rate of ~1/2 tsp in a 2 liter starter.

Let's look at this particular starter. Yeast was harvested on 4/2/2016. I kicked the starter off on Thursday night (4/21). 24 hours later, I had a very small krausen. It was huge anf fluffy by ~40 hours.

This is not at all unusual for me.






Posted 34 days ago.

ingoogni
nl
314 Posts


How much yeast do you add to the starter?
I add the yeast, then spin for a while to get some oxygen in to it, then I stop and wait until there is visible activity. Spin for ~12-16 hours, scale up if needed.
Don't look at the krausen, look at the colour, should look cream / off-white.
For the yeast nutrients, I put into the starter what is advised for the whole batch. Growth exhausts nutrients fast.

Excellent presentation on yeast propagation:
www.mbaa.com/districts/Northwest/Even...




Posted 34 days ago.

vinpaysdoc
Charter Member
High Point, NC
321 Posts


It's done when the krausen falls, it smells like beer (not wort), and it's cloudy from the yeast.




Posted 34 days ago.

testingapril
Charter Member
Atlanta, GA
595 Posts


I'm sure mchrispen will pop in with some Mark VD info on cell divisions and timelines that will be more accurate than what I'm going to provide, but it'll still be fine.

Zainachef and White have reported that yeast have completed the vast majority or even all of the cell divisions they are going to do in 12-18 hours. So pitching when anaerobic fermentation begins (or just after) in 12-18 hours will give you max cell density and as Kid said, there is still plenty of yeast nutrient available in the wort so they should be at max vitality at that point.

There are some reports that finishing fermentation and then crashing and decanting is actually resulting in a good bit of cell death and loss of vitality. Again, mchrispen can probably provide more info here.

But in any case, this sort of info is most of the reasoning behind why I started harvesting wort from the beer I was brewing to make a starter. That way I wasn't diluting the wort too much with gross extract wort that had been fermented completely and might have off flavors. I pitch the next day anyway so no reason not to use "real wort."





Posted 34 days ago.

homebrewdad
Charter Member
Birmingham, AL
2480 Posts


As for how much yeast I pitch - I typically start with ~100 billion cells, minus the inevitable death over time. I seem to get pretty consistent results, though, whether I start with a fresh vial, a partial harvested vial, whatever.




Posted 34 days ago.

testingapril
Charter Member
Atlanta, GA
595 Posts


BTW, why are you adding yeast nutrient after cooling? It's supposed to go in the boil IIRC. I never use it though. I figure if malt and water doesn't have what yeast needs then we're all screwed anyway.





Posted 34 days ago.

testingapril
Charter Member
Atlanta, GA
595 Posts


Sorry, that sounded rude or accusatory. I didn't mean it that way at all. Just curious. Maybe I don't know how it's supposed to be used since I don't use it.





Posted 34 days ago.

homebrewdad
Charter Member
Birmingham, AL
2480 Posts


Nah, I didn't take that as rude, just as a legit question.

Why do I add it after cooling? Perhaps because I'm a ninny? I seem to recall reading that it as supposed to go in after, so I have always added it after the boil. I have zero other reason for doing so.




Posted 34 days ago.

mchrispen
Bastrop, TX
485 Posts


Lol @ TestingApril... of course I have an opinion.

If the purpose is to build cell count, that is finished as yeast replication leaves the exponential cycle, has taken up and metabolized both O2, zinc and Mg resources. Crabtree limits cell count by volume. The traditional homebrew starter takes yeast through lag and exponential to the crabtree limit (which is why starter volume matters), through anaerobic respiration and fermentation, and finally into dormancy, where hopefully there are sufficient trace minerals to allow it to prepare for a dormancy period. In theory, the optimal pitching time is at the beginning of high krausen, assuming the pitching temp and starter temp are the same. This presumes the yeast are fully hydrated, have sufficiently taken up necessary respiratory-required nutrient, and biomass is equivalent to your fermenter volume requirements. Tempering the yeast starter to pitch temperatures (IMO) is important to not shock the yeast into dormancy. From a yeast count perspective, I like to be within 50% of the required pitching cell count. This contradicts the Yeast book recommendations, aligns with the B&Q fermentation book, and aligns with Kaminski's viability starter theory... with a few caveats.

Jamil's starter calculator focuses on estimated biomass/cell counts in dormancy, with the proper increases required for wort gravity and volume. It only accounts for estimated cell death over time and doesn't account for potential viability. The goal is to limit lag and get the yeast up to exponential, which requires O2 or proper nutrient charges (both must be added by the brewer somehow).

If the yeast is active, during the next replication cycle in pitched wort, the daughters should take over and will go through shortened lag, exponential (aerobic) and anaerobic fermentation reaching the crabtree limit within 2-3 replication cycles. Yeah, yeast ranching.

The yeast from White Labs is dormant, as is Wyeast, however the latter's nutrient pack helps to prepare the yeast for another lag phase, and causes any not-so-dormant daughters to start anaerobic fermentation - swelling the package. For what it is worth, I still use my stirplate, but at the lowest possible speed to barely keep the yeast in suspension but absolutely no whirlpool dimple during the lag and exponential phase. I turn it off after any krausen shows, and with the slow speed it piles up just like a shaken starter. This replaces my random shaking thing. However, I preference viability and activity. The starter wort smells just like sweet beer wort and I happily pitch the whole starter without crashing and decanting.

I guess the question is:
1. Are you using a starter to grow biomass?
2. Are you using a starter to ensure viability?
3. Are you looking for proof that a vial or package of yeast is viable?

Olan, I guess to answer your question, it depends on your goals. Might be a fun side by side evaluation.

Using my method, I have seen as little as 30 minutes lag in a 55 point ale, pitching to cell count, but erring on the side of viability, pitching at start of krausen. I am also tempering the starter to temps - I am beginning to believe the data that yeast are very sensitive to temperature changes > than 5-10F a day. Not sure about the so called off-flavors, but certainly yeast can fully floc out leaving before cleaning up off flavors.






Posted 34 days ago.

Necropaw
Charter Member
Central WI
608 Posts


That was a lot of reading for a Monday....




Posted 34 days ago.

homebrewdad
Charter Member
Birmingham, AL
2480 Posts


Great reading, Matt.

I run my starters to completion, usually 3, sometimes 4 days. I cold crash, decant, pitch what I want to pitch, save some yeast for next time. I hate to pull up yeast for storage when fermentation is incomplete, as I'd prefer to not have exploding vials (though, I suppose the the cold of the fridge should curtail that).

For what it's worth, I can't recall the last time I had an ale - even my typical mid 60s to upper 70s gravities - lag longer than 3-4 hours.




Posted 34 days ago.

mchrispen
Bastrop, TX
485 Posts


>For what it's worth, I can't recall the last time I had an ale - even my typical mid 60s to upper 70s gravities - lag longer than 3-4 hours.

Seems like your process is solid. I would encourage you to pitch one at the start of high krausen when you can observe any differences. If you still have the brew bug, it might provide some telling data.

I have NO idea if this provides a flavor advantage or disadvantage. I just had an incredible IIPA that was fermented with a single vial of WLP001 and fermented at room temps. Despite some aging hop flavors, the ester profile was lager like - super clean and crisp, I swear I had a clear notes of 2-row graininess and C-40 (I was right, but didn't write that specifically). I was shocked when the test coordinator said he thought it would make a great Tasting exam beer, and was disappointed when it was really good. So he aged it for 3 months before serving it to us yesterday.

I really should stop being lazy and steal Brulo's blind triangle tests (and format and logo and tshirt memes and fanny pack) and do a few blind triangles with this method.




Posted 34 days ago.

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