Overpitching?

[drsmurto]

Sorry to double post, well, sort of. Posted this on AHB as well.

Did a google search of AHB and came up with a few threads on this. Seems that it is possible.

I collected the wyeast 1098 trub from an ESB late last year, washed it etc. Decided to use it in a porter i brewed saturday (well, truth is i didnt label it and thought it was 1056 so was making a starter for an APA but memory kicked in before i used it) so i made a 2L starter (SG 1.044) and stirred it for 4 days. I pitched this into 23L of porter wort @ 1.054. 24 hours later the krausen was climbing out of the airlock. Temp is around 20C (ferment fridge died so its inside - thermo in a conical of water next to it says 19.5).

My aeration technique is - i lift the freshly chilled wort up to a height of about 1 m. 2 hours later the cold break has settled to the bottom so i open the tap up and it drops 1 m to the bottom of the next fermenter where the starter is waiting for its food.

Am not panicking, its just i havent experienced this since the good old days of coopers kit yeast and 28C........ in fact it reminded me of those times so much i modified the airlock in the same fashion as i did 10 years ago. (see pic)

Have i massively overpitched and what will the end result be? There isnt a lot of info about this strain on the wyeast site.....

Cheers
DrSmurto

Here's a dodgy phone pic of the airlock addition.

[Kevnlis]

I wouldn't worry too much. I once did 4 consecutive toucan brews on 24g of Ross's Nottingham yeast which was pitched to the first of the series. I aerated every wort that went onto the trub. I did not wash the slurry between brews. They all came out great!

I think it is pretty hard for a home brewer to over pitch. I usually try to get 3-4 brews from every starter of liquid. Gotta get your moneys worth!

[Trough Lolly]

You'll be fine Doc - I'd much rather a vigorous ferment than a slow sleepy strained one! One point to note is that you don't have to aerate the wort when you repitch onto an active slurry. We like to aerate the wort to help the yeast adapt to the wort and grow in numbers during the adaptive phase, before the yeast moves into the anaerobic fermentation / attenuative phase, typically some 16 hours after pitching. If you have active fresh yeast in a fermenter, pitching in the wort as is, will do the job and you shouldn't notice any difference. Don't fret that you have aerated the wort - the vigorous fermentation will help push the air out of the wort anyway so you shouldn't have any oxidisation risk due to unnecessarily aerating the wort.

Cheers,
TL

[drsmurto]

Cheers for the votes of confidence Kev/TL. Its one vigorous ferment and still going strong. I made a starter of an already large amount of yeast so am beginning to see what i did 'wrong' or more correctly, unnecessarily. I had planned to top crop the krausen but remember that the magnetic stirrer went into the wort with the starter! Only have one mag stirrer bar big enough for the 3L conical.

[Kevnlis]

...3L conical.

We still don't have that drool smiley Oliver

[drsmurto]

I use the 3L conical for ales, save the 5L conical for lagers

[Kevnlis]

I use the 3L conical for ales, save the 5L conical for lagers

Yeah, yeah, yeah... your just showin off now

Geez a 5L starter, I hope you bottle the beer off the trub!

[drsmurto]

Mmmmm, unhopped maltyness?

No, i let the yeast drop out of suspensionm usually by cooling it and turning off the stirrer and then decant the 'beer' and pitch mainly slurry. Before i had a chiller i would cheat and crash chill 5L of wort and use that as a starter (which i did back in the kit days on the odd occasion) and the next day once the rest of the wort had hit pitching temp, dump the whole starter in and yes, i still forget to take the stirring bar out. Every bloody time!

[James L]

Is there a reason why you use conical flasks DrS? i was looking through the ROWE scientfic catalogue and the schott bottles are always rather cheap, plus they come with a lid... I was gonna grab a couple of 2L ones so i can make some 2L starters, and also make a bit of a yeast collection with those smack packs. I know that i can easily autoclave them at work if i need to, and i know that they are quite tough.

Also mate, do you make starters with extract? or do you use sterile wort from previous brews?

[rwh]

I use conicals on my stir plate because of the shape of the bottom. The flatter the better, right? Not sure what the bottom of the bottles would be like.

[James L]

they do have a little bit of a bump... so it could effect the stirring, but not a great deal. It would also depend on the length of the stirring bar.. the longer the more stable.

I'll make some inquires...

to store the cultures in the fridge, do you just fill and seal sterile beer bottles?? or have you since found something more effective?

[rwh]

I tip off the beer and then pour the slurry into a few sanitised stubbies and cap. I wish I had test tubes or something though because stubbies are a waste of space in the fridge.

[Kevnlis]

Get some hop extracts from Ross and use iso-hops to bitter in the bottle. Problem solved

[drsmurto]

Damn it, i wrote a nice big reply but hit preview instead of submit. Muppet!

Schott bottles have curved bases and will be no good for starters. If you try and stir the stirring bar will likely not be happy and try and bounce around. If you stir too fast you risk smashing the flask. Trust me, 12 years working in synthetic labs, i have seen this done far too many times, never by me of course

I use 50mL centrifuge tubes to store yeast samples.


Also, heres the 3L conical with a 5L demi-john on the left. It also has a curved bottom so i cant use these for my 5L starters. They are for experimental beers!

[James L]

Yeh i use those 50ml centrifuge tubes.. mine arent the lovely sartstedt ones that you seem to have, they are rippers though... and they're already sterile....I have managed to get some nice foam centrifuge tube holders that you can stack... cheap as chips...

So do you ever just culture the smack pack just in extract, pour into centrifuge tubes then store, or do you always use the yeast in a brew first, then harvest the trub then store?

[rwh]

Cool just got myself 100 centrifuge tubes with caps for $27 incl postage off ebay. Mine have flat bottoms so I'm hoping to just be able to chuck them in the fridge. Don't think they're sterile tho, so I'll have to sanitise with iodophor; I'm assuming heat's out of the question due to plastic being rather meltable (as is flaming the entrance... tho the caps seem to cover that so I'm hoping it's not too much of an issue).

I normally make a starter from the smackpack and split six ways and store, slurry only, in the fridge in capped stubbies (soon to be centrifuge tubes). I've been able to keep them for months and they still fire up really well. I usually make a starter in 1.5L water with 150g LDME boiled up in a little water and topped up with cold. If I'm starting from a culture that's been in the fridge for a while or if I'm making a high gravity beer or low temp lager, I might step it up a couple of times to build a nice high population.

[James L]

sounds good...

I have tried to "farm" my trub when i used the 3068 liquid yeast... and it waspretty straight forward, i have had them in the fridge since about august last year, and i cracked one open just the other day and made a starter no worries at all....

If those centrifuge tubes are sterile, they are usually sealed in packs of 10 with the lids already attached to the tubes... If the lids and tubes are separate, they'll need spraying..

those tubes are so much tidier than bottles, and if you get racks, you have no chance of knocking them over whilst they are in the fridge, and you can store them in rows of 4-5... easy to lable and disposable...

For some reason, i just thought that it was a little more involved that what i was already doing... but it doesnt seem so.

[drsmurto]

So far i have only farmed the trub. The smack packs i have been getting are less than 2 weeks after manufacture so swell up in 30-45 mins. Think i will try and make starters first as washing trub can be a pain altho i am trying hard to let the cold break settle first and then pitch yeast onto a clean wort. That helps. Also contemplating top cropping at high krausen. So many different methods.

[James L]

how many 50ml lots do you usually end up getting from the one trub? I try to stick to 5...

and also, if i was to try to make cultures from the smack pack. what sort of a volume should i be looking at growing it in? 1.5L? then let it settle, pour off supernatant, and collect in 6ish tubes? 10 ish?

[drsmurto]

I get between 5-8 tubes per trub altho they are only half full.

If i was to make a starter out of a smackpack - 1.5-2L aiming with 100g LDME per L. As rwh said, build it up a few times if you want a bigger population, particularly if brewing lagers. The one i pitched into the porter was a 2L starter built up from the entire trub of another beer. The yeast was in the fridge for 4 months. In theory i could have just pitched all 7 vials but i chose to make a starter out of them all and then pour off one vials worth to keep for next time.