Yeast starter (when's it ready)

[peebee]

This is a hint post rather than a question (unless I have it wrong!).

I've always been puzzled why some people have trouble getting a fermentation going. For me I chuck the yeast in and 6-18 hours later it's fermenting; it just happens that way. This might be one explanation?

Today was to be a brew day. Everything ready and the yeast starter has been clattering away (magnetic stirrer) for the past 36 hours. But I was suspicious about the starter so brew day is postponed.

I'd had this before with a near best-before date WLP002 (Whitelabs) yeast, hence I left it 36 hours. All the starter calculators are great at telling you volumes, step ups, malt extract amounts, etc. but gloss over another important factor … time. You can get the impression that 24 hours is enough, and for a reasonable "fresh" pack it seems to be. But a less than fresh pack? How do you tell the starter is ready? Foam and bubbles isn't a good indicator if using a stir plate because they quickly knock the gas out making it less of an indicator. If using a stir plate there won't be a sediment forming either. What I do is obvious, but perhaps some folk just put too much trust in the calculators and "24 hours"?

I'm suspicious of my starter because WLP002 is famous for creating large flocs, but the starter hasn't taken on its "snowstorm" appearance. If I was using other yeasts I wouldn't expect flocs anyway. So sterilise a pipette and take a wee sample. Stick a couple of drops on my refractometer and take a reading (if you use a hydrometer this is going to be more involved). Put the reading into a correction calculator (fermented wort, OG 1.037 or 100g dried malt extract in 1L) and out comes … 1.037. Clearly this starter hasn't even begun to "start"; if I'd chucked it into my day's hard work I'd be waiting a week for it to start before ditching it 'cos its gone off.

So I don't start my brew day, I contemplate what folk do it they treat their older liquid yeast packs as "direct pitch" (Wyeast) or even just not give it adequate time in a starter, and I unexpectedly get free time to bore you all with this drivel.

 

[strange-steve]

I haven't read the yeast book yet but the co-author JZ in his BCS book says that a 2L starter made with healthy yeast will reach maximum cell density within 12 to 18 hours, however if you are starting with low viability yeast then it could take 24 hours or more, which is essential what you're saying.

I'm one of those people who gives it 24 hours and dumps it in, but I suspect that even if the starter isn't complete it won't matter all that much. Have you read anything on vitality starters?

 

[foxbat]

I've had one that was close to the best-before take 36 hours to start showing any signs of fermentation. I find it quite obvious when it's done as it changes colour to a light cream and you can see all the little particles being whisked around (or big egg-drop soup particles if it's White Labs 002). Other symptoms like a krausen tidemark are giveaways too.

 

[F00b4r]

It depends on how old your yeast pack is. You might even be looking at 72 hours or longer for a first step if the pack is out of date and you are starting with an initial small step, something you should be looking to do with low viability.

 

[matt76]

I've had one that was close to the best-before take 36 hours to start showing any signs of fermentation. I find it quite obvious when it's done as it changes colour to a light cream and you can see all the little particles being whisked around (or big egg-drop soup particles if it's White Labs 002). Other symptoms like a krausen tidemark are giveaways too.

I'm still quite new to brewing and even newer to making starters on a stir plate - but yeah, that's something I've noticed, it goes from a kind of strong tea colour to a more milky tea

 

[ACBEV]

My yeast starter method is non-scientific and I have no idea how much yeast I'm pitching, but it seems to work well. For Me!!

I buy a pack of Wyeast and a jar of Meridian Malt Extract (370g)

I mix the malt extract with 4L of water and bring to a boil, cool and pitch yeast into a demijohn with liquid. Leave for 3 days, give a good shake, bottle and put in fridge. This gives me 8 x 500ml bottles of yeast for pitching into my brews. Brews over 1.050 get two bottles of yeast.

 

[peebee]

Thanks for all the input everyone. But you're all missing the point of my post; you're all well experienced brewers with sound management techniques of their yeast starters. I'm aiming my post at new comers to yeast starters. I too have loads of experience but not much with liquid yeasts and starters so I'm well aware of the uncertainty they can cause or the attraction of putting (misplaced) faith in many of the documented practices around starters.

24 hours ago I'd got a suspicious looking starter so I applied my usual "trick" and took the gravity. It was 1.037 and it began 36 hours earlier at …. 1.037! If I'd gone blindly ahead with that starter I'd be waiting into next week for any activity and probably lose the brew to some bug or other. Instead, having taken an inarguable and simple (especially so if you have a refractometer) gravity reading I postponed brewing for a day. Now look at the starter (now 50 or so hours old):

Okay, for this yeast (WLP002) the flocs (lumps!) are indication enough, but I take a gravity reading and it's 1.014, i.e. it's ready and there's no relying on experience to tell me that.

I'm hoping newbies to liquid yeast starters (and a few experienced?) can use this simple but seemingly undocumented method to avoid anxiety and potentially failed fermentations.

 

[foxbat]

WLP002 flocculates into such thick clumps I've had it kick the stir bar off the magnet before!

Good luck with your (postponed) brew. This yeast does make a tasty brew especially when fermented at English not American temperatures.

 

[peebee]

WLP002 flocculates into such thick clumps I've had it kick the stir bar off the magnet before!

Good luck with your (postponed) brew. This yeast does make a tasty brew especially when fermented at English not American temperatures.

Brew boiling at moment, I'll be writing it up (or the next brew) 'cos it's a "trial" of a "full boil mash" ("full volume mash", i.e. no sparge) in a Grainfather. No drop in efficiency despite "no sparge", odd that but told to expect it from the BIAB crew. But creating a strong bitter (SG 1.055) using this "no sparge" method is pushing it a bit (too far!) for a 30L Grainfather (21.5L batch). I'm doing it because arranging sparge water for a Grainfather is a pain in the butt.

Cheers!

 

[F00b4r]

PeeBee the idea of a starter (steps) is growth not fermentation so gravity measurements is probably not the best guide. I see there seems be be some other references to advice found on Jim's forum, you might be better asking the question there as there are members there that work with yeast for a living. Following advice from one of them on an out of date smack pack, I had one of the quickest and strongest ferments I have ever had and given that we just make wort and the yeast makes beer it would seem to worth refining this part of the process.
I don't want to mangle his advice so would ask the question there but some of the takeaways were that people make starters/steps much quicker than is optimal, are not optimising for growth over fermentation and with less viable yeast it is better to start small to get it back to its best (the latter will give you better year than a very fresh snack pack).

Edit: I agree that most of the advice out there isn't great and/or vague and isn't helped by people claiming bad processes that "work for me".

 

[foxbat]

PeeBee the idea of a starter (steps) is growth not fermentation so gravity measurements is probably not the best guide. I see there seems be be some other references to advice found on Jim's forum, you might be better asking the question there as there are members there that work with yeast for a living. Following advice from one of them on an out of date smack pack, I had one of the quickest and strongest ferments I have ever had and given that we just make wort and the yeast makes beer it would seem to worth refining this part of the process.
I don't want to mangle his advice so would ask the question there but some of the takeaways were that people make starters/steps much quicker than is optimal, are not optimising for growth over fermentation and with less viable yeast it is better to start small to get it back to its best (the latter will give you better year than a very fresh snack pack).

Edit: I agree that most of the advice out there isn't great and/or vague and isn't helped by people claiming bad processes that "work for me".

I think what you are referring to there is the pitch rate and the online calculators do take that into account in conjunction with the estimated viability.

 

[peebee]

PeeBee the idea of a starter (steps) is growth not fermentation so gravity measurements is probably not the best guide. …

That's right, and perhaps I give the wrong impression?

What I look for is: Gravity same as what it was at start -> there's nothing happening yet. Gravity less than it was at start -> things are getting going.

It's about avoiding putting in a dud starter based purely on faith: "It'll be alright" (because the guides say so), but it doesn't have to be.

When the measurable sugar in the starter has pretty much gone, there wont be significant further fermentation or growth.

So my advice is dodgy? But it's 100 times better than blind faith. Because of that, I'm happy to be recommending it.

 

[matt76]

That's right, and perhaps I give the wrong impression?

What I look for is: Gravity same as what it was at start -> there's nothing happening yet. Gravity less than it was at start -> things are getting going.

It's about avoiding putting in a dud starter based purely on faith: "It'll be alright" (because the guides say so), but it doesn't have to be.

When the measurable sugar in the starter has pretty much gone, there wont be significant further fermentation or growth.

So my advice is dodgy? But it's 100 times better than blind faith. Because of that, I'm happy to be recommending it.

I think what you are doing is good - you are taking reasonable steps to ensure a healthy starter before pitching.

And I mean reasonable in the sense that you could write down a list of reasons why you did it this way.

Are there better ways? Maybe. But your way is at least methodical, systematic and repeatable - useful to help trace faults and indeed improve in the future.

It strikes me as a much better approach than blind faith!

 

[F00b4r]

I think what you are referring to there is the pitch rate and the online calculators do take that into account in conjunction with the estimated viability.

Nope, pitch rate and the online calculators just refer to numbers of cells, it has nothing to do with how healthy they are or what state they are in (important too). You then can get a knock on effect on subsequent repitches.

 

[F00b4r]

That's right, and perhaps I give the wrong impression?

What I look for is: Gravity same as what it was at start -> there's nothing happening yet. Gravity less than it was at start -> things are getting going.

It's about avoiding putting in a dud starter based purely on faith: "It'll be alright" (because the guides say so), but it doesn't have to be.

When the measurable sugar in the starter has pretty much gone, there wont be significant further fermentation or growth.

So my advice is dodgy? But it's 100 times better than blind faith. Because of that, I'm happy to be recommending it.

I think what you are doing is good - you are taking reasonable steps to ensure a healthy starter before pitching.

And I mean reasonable in the sense that you could write down a list of reasons why you did it this way.

Are there better ways? Maybe. But your way is at least methodical, systematic and repeatable - useful to help trace faults and indeed improve in the future.

It strikes me as a much better approach than blind faith!

I am not recommending blind faith, pretty much anything is better than that but something being methodical/repeatable does not necessarily make it any better. In my initial reply I mentioned where proper advice, from people who have spent decades of their professional life working with yeast, could be obtained. Anyone can make wort, there is a reason why most brewers start to focus on the fermentation aspect as they expand their knowledge. Just following some basic advice and getting some more clarity on the process improved my fermentations significantly and better to get that advice from the source direct rather than my interpretation of it with the likely small errors in understanding (that would undoubtedly get magnified with each retelling by others). There are some people in the hobby with a wealth of experience and knowledge who are generous with it so why not take advantage of it.

 

[peebee]

15 hours after pitching this "once considered dead" starter has got an active fermentation going (been going for a few hours).

Don't listen to "distractors", they'd prefer novices are kept in the dark so they can stay as novices. Just ignore them … I do.


Before I go, I'll give a sneak notification of another yeast starter trick I use. It's quite advanced and uses a technique called "transmutation". Basically it means you'll never use yeast that isn't absolutely fresh. The "transmutation" changes any lead you have into gold. Well "it works for me".

 

[F00b4r]

15 hours after pitching this "once considered dead" starter has got an active fermentation going (been going for a few hours).

View attachment 18601
Don't listen to "distractors", they'd prefer novices are kept in the dark so they can stay as novices. Just ignore them … I do.


Before I go, I'll give a sneak notification of another yeast starter trick I use. It's quite advanced and uses a technique called "transmutation". Basically it means you'll never use yeast that isn't absolutely fresh. The "transmutation" changes any lead you have into gold. Well "it works for me".

Who are the distractors?

 

[peebee]

I haven't read the yeast book yet but the co-author JZ in his BCS book says that a 2L starter made with healthy yeast will reach maximum cell density within 12 to 18 hours, however if you are starting with low viability yeast then it could take 24 hours or more, which is essential what you're saying.

I'm one of those people who gives it 24 hours and dumps it in, but I suspect that even if the starter isn't complete it won't matter all that much. Have you read anything on vitality starters?

Thanks @strange-steve . I've read through that article on "Vitality Starters" a few times so to get it sunk in. It's all a bit high-brow for what I wanted of this post, but interesting. I particularly like that you can treat a liquid yeast "vitality" starter like dry yeast, i.e. don't bother aerating the wort (but info on not aerating dry yeast pitches applies to <1.050 worts, I'll have to guess this applies to "vitality" starters too?). I might be tempted to give it a go, but only with a very fresh yeast pack; the article ends with a paragraph which I'll take as a warning.

But the rest of your post: Yes, it was essentially what I was saying. But taking out the guess work or experience observing starters to judge when the starter is as ready as it's going to be. I'm pretty sure "my" technique (looking for shifts in SG) wont help for "vitality" starters, or even register the end of "growth phase" 'cos I know growth will demand less sugar than just basic gluttony. But the main purpose of the technique was identifying when a starter isn't ready ("vitality" starters aside!) and perhaps save some soles from inadvertently pitching a dud starter.

 

[strange-steve]

Well this is a starter of WLP530 which is coming up on 24 hrs now and as you can see it's as still as a millpond, but I'm not brewing till Wednesday so plenty of time to go. The calculators estimated this yeast at 50% viability which isn't all that bad, I've used much worse, so I was a little surprised to see no activity as yet.