New to liquid yeast

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Hey guys, I've been lagering for so long with just 34/70 dried yeast that I continue to reuse over and over again by taking a litre of slurry from bottom of my fermenter at kegging, keeping in the refrigerator until next brew day and things have been fine

I purchased a few different lager strains the other day, all which only have a couple months left until use-by mind you. White labs instructions said pitch one vial straight from the packet without a starter for my particular wort so I did this at 12 degrees. A whopping 4 days later and I'm only just (barely) seeing any sign of fermentation at all. Took a hydro tube sample this morning and was watching it thinking maybe I could see the slightest movement of particles but wasn't sure if I was just imagining it. Coming home now a few hours later though there's a small krausen forming

So, going forward is it fine if I just continue taking slurry and repitching that a few weeks later into new wort, or does this need a new starter each time? I'm guessing this first fermentation will build numbers up to an acceptable level from what was a big underpitch

Thanks all
PS, Krausen in hydro tube that is (which could be leftover 34/70 that dried after washing tube a few days ago).

Fermenter still looks dead as a doornail..
Reusing slurry is a very popular way of reusing yeast Doc and it saves a few dollars too. I know Wyeast have a slurry rep itch calculator so Whitelabs may also have one. Whitelabs
To keep taking repeated slurries and expecting good results you would need to be using very clean techniques Doc, it may well be that this last slurry has run out of steam. How many times have you repitched consecutively?
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Thanks mate, all my previously dried yeast slurries have always been ok. This one is my very first liquid pack from White Labs, WLP833 German Bock Lager apart from a WLP300 I've been using for almost two years now.

I don't think they run out of steam, they keep breeding as others die off. It may mutate after a while though
I've generally been replacing the dried yeast slurries after about 5-8 uses as a preventative practice. Probably should really get myself a new 300 too come to think of it, it's been a long time. Could probably patent and sell as a new hipster strain by now 😂
Depending on your batch size, a single pack of liquid yeast pitched directly is probably quite an under-pitch for a lager, especially if you pitched at a rather cool 12 deg, and especially if the pack is approaching its use-by date. I'm sure you will produce enough yeast to ferment the batch once it gets going, and create more than enough yeast slurry for your next brew. But be prepared for some off flavours for this batch due to under-pitching, and don't be put off this yeast strain if it doesn't turn out great this time.

I know you're not using W-34/70 for this batch, but as an example Fermentis published this:
Rediscover the SafLager W-34/70 • Fermentis
Apart from showing that W-34/70 works at a wide range of temperatures, the results indicate off flavours with under-pitching, and that at cooler temperatures you'll need more yeast cells.
Once your beer has fermented, the slurry from either dried or liquid yeast will behave the same.

I strongly suspect you have underpitched, and probably should have cultured up the White Labs yeast on a stirplate (or similar) to give you enough volume of yeast.

I have a brew lagering at present, and although I used a Wyeast smakpak, I cultured it up twice to end up with the equivalent of about 4 or so smakpaks which was pitched into 25 litres of oxygen injected wort. It fired up within about a day or so at 9ºC. It's difficult to overpitch lagers cold fermented on a home brew scale.
So it's morning on the fifth day since pitching and still no activity in FV.

Peering in with my lid off I can see the odd tiny bubble rise to the surface if I wait long enough, have given it a rouse and raised temp to 17. This is officially the longest lag I've ever experienced. Not sure why my hydro sample got going so quickly, it's as though all the yeast were sitting at the tap waiting to be poured out
Unless you give your hydro tube an industrial strength cleaning and sanitise, it’s no surprise it’s fermenting. I’ve often left post boil samples in mine overnight and found it fermenting the next day without any yeast, but it’s had fermenting beer in it many times and I generally just rinse it, so god knows what kind of hybrid yeast lives in the plastic
True, true. I used to think it was wild yeast just blowing in but this is probably more likely
I've been brewing lagers for 20 years and mainly use the W34-70/S189 dried yeasts, with the odd occassion I use a liquid yeast. With either whitelabs or wyeast (cant remember which one), they've recommended to pitch a vial straight into the fermenter at a higher temp first, then when you see activity, slow the temp down to your recommended range. I've used the budvar strain and pitched at 20-24c and left it there for 12-24hrs from memory until I saw krausen, then slowly drop down a few degrees per day. I wasnt fussed getting some esters for the first batch (As this could occur with a warm temp and yeast growth stage), becuase Iiked the esters it produced anyway, but then when I reuse the slurry, I'll pitch colder.

With a pitch at 12c, you probably missed that extra growth opportunity. Just my thoughts
True, true. I used to think it was wild yeast just blowing in but this is probably more likely
Hey mate,

Not to flog a dead horse or anything but i'll give you my thoughts (I have a Czech Pils going at the moment) on liquid yeast and W34/70.

I am not a fan of W34/70, and that's just my personal opinion. I don't like the flavour, and find it is not as crisp as a good WLP802 Czech Budejovice that's properly treated.

If you are serious about reusing yeast, then I would suggest investing in a stir plate, flask etc and overbuilding your yeast then harvesting from there. I build my own stir plate (could have probably bought one for less in the end) using a computer fan, some rare earth magnets and a tupperware (don't tell my wife). Essentially, my process is simple for preparing any form of liquid yeast, and it goes as follows:

Work out how much I need to pitch, for most Ales I go for 1L and for most Lagers I go for 2L. This is a rule of thumb for me, and makes it easier for my simple brain. I then overbuild by 500ml. When the starter is done, before crashing it I pour off 500ml of the liquid into a clean canning jar (the ones you get with the two part lids) Kleiner I think they are.

I put the lid on loose, and pop it in the fridge with the date and strain on it. Then, next time I need to do a starter I just pour off about 450ml leaving a little liquid to slosh in the bottom and use that. It means clean, non 'fermented' yeast being re-harvested. The issues with slurry is that you get hop debris, proteins, lipids and all sorts that have fallen out of ferment. Not much of it is viable yeast. I have found anecdotally that 10 generations from one packet have not mutated, but I usually dump and restart after this as an insurance policy. It also brings the cost down to about $15/10 ($1.50) per generation plus DME being $2 call it, making it $3.50 per pitch. This lets me use any strain I want, and I always have a packet or two of dry stuff in the freezer for emergencies.

Just a thought, but with a little investment, some time and patience you can get a good yeast harvesting system going. It let's you open your horizons into different strains too. I have German Kolsch, London Ale III and Czech Budvar as my main ones, but also experiment with others. Oh and Dennys Fave 50 for porters and stouts.
My 2c worth, agreed with the yeast harvest and propagation.

I did use white labs high pressure lager yeast and found it really hard to get clear. Got there in the end but needed cold, gelatine and Super F.

Wouldn't use that again if I wanted a quick lager. Taste was ok.
Thanks man, some good food for thought there. It would be nice to keep a few more strains handy. I just can't justify paying $13 per pitch
If you can pressure ferment I've just done a pilsner, hot fermented with Kveik Opshaug 35 celsius and home brew club thought it was really good last night.
Bought one sachet , used half for one brew and half in another. Dried out the yeast from the collection bottle and then just lob in about 5cm square of flakes for next brew. No building starters and that first batch is going to do about 50 brews.
Well I'm pleased to report we finally have takeoff! 😀🤟✅🍺 Fine bubbles after rousing this AM and full krausen tonight. That's five full days lag

I also bought a Copenhagen lager yeast vial too with the same use by date. Will be making a big starter at least a few days before brew day for that one!
Good plan, I built up a really healthy starter from a yeast that said it expired 14 months before I started to culture. The calculator said no viable cells but there was. Save some of the starter after washing in the fridge so you have first generation for your next brew.
This reminds me of a similar story. I have used German Bock yeast once before which is going on 2.5 years ago now when I used to bottle condition my beers. I lost this vial in a house move and assumed it had actually been lost but found it a few months later at use by in the open door of a fridge we'd had sitting in the styfling hot shed for months!

Thought, why not give it a try.. I can't recall wether I just pitched it straight or made a starter but don't recall any problems with it at all and the end product was terrific so just goes to show how resilient yeast really can be

Interested to see how it turns out kegging because bottle conditioned beers are too unreliable but it was incredibly good so I hold high expectations