# saflager 34/70 cold pitching method question



## JoeyJoeJoe (26/8/13)

Hi

It has been about 8 years from my uni brewing days that was all about massive quantitiy over quality as it only had to taste better that cask wine  I now want to get back into brewing but do better job.

I have been reading all over this site and others but I still have a question that I cant find the awnser to.

I want to make a lager I already have the kit and malt and have bought 2 packs of the w34/70 yeast. (I also finished setting up my stc-1000 and deep freeze today!! what a great little device!).

I have read all about dry pitching and rehydrating my problem is that I did a trial today with a half filled fermenter and the temperature is going to take a fair while to get from the 23C pitching temp to the 12C fermenting temp that fermentis recommends. Maybe 12 hours! First question is this too long???? 

So if I go the rehydrate and cold pitch method do I have to cool the rehydrated yeast down to 12C before I pitch? Also do I have to warm the yeast up before I rehydrate? (currently in the fridge)

Anyway for the cold pitch method does this sound like a plan.
1. mix up kit and malt in hotwater add to fermenter.
2. add tap water to fermenter seal up and put in freezer(set stc to 12C taped probe to fermenter)
3.Wait
4.Stc says 12C YAH!
5.Warm up yeast in my pocket for 5 minutes. then Pitch in to about 500ml of room temp water.put some glad rap on top.
6.Wait 30 minutes give a little stir
7.Put yeast mix in freezer aswell.
8.Wait 30ish minutes? For it to cool down then pitch??? 

Brew day is tomorrow help me out!!!

Thank you

James.


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## manticle (26/8/13)

Firstly rehydrate according to manufacturer's instructions.
Secondly I prefer to pitch cool but it's easy for me to do. I would prefer to pitch warmer in your situation than leave it 12 hours.

However set the temp at about 8 rather than 12. You will struggle to get that frrmenting wort down much below 15 if the fridge is at 12. Fermentation produces heat. If you have a thermometer, draw off a sample into your hydro tube and measure it.


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## JoeyJoeJoe (26/8/13)

all fermentis say is the following

　
rehydration instructions
Sprinkle the yeast in minimum 10 times its weight of sterile water or wort at 23°C± 3°C (73°F ± 6°F). Leave to rest 15 to 30 minutes.
Gently stir for 30 minutes, and pitch the resultant cream into the fermentation vessel.
Alternatively, pitch the yeast directly in the fermentation vessel providing the temperature of the wort is above 20°C (68°F). Progressively sprinkle the dry yeast into the wort ensuring the yeast covers all the surface of wort available in order to avoid clumps. Leave for 30 minutes, then mix the wort using aeration or by wort addition.

It doesn't say if I have to cool the rehydrated yeast or if taking 12 ish hours to get down to femernt temp is ok? I actually think there instructions could be a lot more detailed.....

Also the temp is the outside of the fermentor insulated with some styrafoam not the freezer temp which is much lower.

Thanks for the reply though.


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## manticle (26/8/13)

I'd just pitch it into your wort and not wait the 12 hours. Temps should be pretty close.

If it were easier to chill quickly, my answer would be different.


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## JoeyJoeJoe (26/8/13)

I could put some water in the fridge the day before to get the wort temp down ? So add half tap water and half cold water? would that be a better idea. Would I need to cool the rehydrated yeast dwon before I pitched it in? 23C to 12C seems like a biggish jump?


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## Ducatiboy stu (26/8/13)

Pitch it warm as Manticle says and let it cool down. The warm pitching should help it fire up earlier. And set your fridge lower that 12..


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## manticle (26/8/13)

Keep it simple for your first. If you don't like the results, tweak the next one.


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## djar007 (26/8/13)

Manticle is suggesting that you either wait or pitch it warm. The risk pitching it arm is you may get an infection. Or undesirable tastes. dms being the main one. here is a link fr some more info.http://www.picobrewery.com/askarchive/dms.htm
Pitching warm is the better option. Then concentrate on desired ferment temp.As suggested.


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## JoeyJoeJoe (26/8/13)

Ok will do. I will pitch it warm and see how it goes. I will also set the temp down abit say 10C because I think you are right it will be cooler on the outside of the fermenter than in the wort.

Thanks for the advice guys.


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## djar007 (26/8/13)

On a side note. I am sure I heard on the radio today that we need to produce more dms in order to drop the temperature of the ocean. But that may be related to growing more algae. Interesting nonetheless.


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## manticle (26/8/13)

djar007 said:


> Manticle is suggesting that you either wait or pitch it warm. The risk pitching it arm is you may get an infection. Or undesirable tastes. dms being the main one. here is a link fr some more info.http://www.picobrewery.com/askarchive/dms.htm
> Pitching warm is the better option. Then concentrate on desired ferment temp.As suggested.


Actually suggesting not waiting if it's a 12 hour wait.
I prefer pitching cold but I no chill and can get the wort where I want it with no risk. If I had to wait 1 degree per hour, I would pitch warm.


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## JoeyJoeJoe (26/8/13)

no chill? Does that mean you use nitros oxide? That sounds hard core because if I had acces to nitros I probably wouldn't need beer


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## Rocker1986 (26/8/13)

JoeyJoeJoe said:


> Ok will do. I will pitch it warm and see how it goes. I will also set the temp down abit say 10C because I think you are right it will be cooler on the outside of the fermenter than in the wort.
> 
> Thanks for the advice guys.


I disagree with this actually, based on my own experiences with insulating the STC temp probe against the side of the FV. Each brew I do, when I take a gravity sample I also do a temp reading to compare against what the STC is reading and it's always pretty much bang on. Just today I took a reading and measured its temp before doing the SG reading. The STC was reading 18.2C, the temp of the sample was about 64.5 - 65F (18.05 - 18.3C). I reckon if you set the temp to 10C you'll end up fermenting it at 10C or thereabouts, not that there's anything wrong with that - it'll still ferment fine.

This is the whole point of insulating the probe, so it isn't affected by the ambient air and actually measures the brew temperature. The rest of the surface area of the FV might be cooler than the wort but that area covered by the insulated probe is (or should be) pretty much the same.


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## JoeyJoeJoe (26/8/13)

Thats interesting. How far along the ferment were you? I imagine the temp difference would be larger at the start when the yeast is generating heat? Maybe I will split the difference and set it to 11.
Fermentis suggest 2 days at 12 and then5-6 days at 14 then 2 days at 15 then lager. I just worry that spendinf the first 12 hours getting down to temp will do.... But I am probably just worring about nothing I can barely tell the difference between XXXX and VB so my palate probably wont care too much. I would like to impress my mates though.....


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## manticle (27/8/13)

My experience is different. Plastic is an insulator and my wort always measures 2-3 degrees higher when actively fermenting.
Have calibrated the stc.

10 deg is good for most lager yeasts anyway.
No chill is a method for full mash or any other full volume method. Not suitable here, no nitrous or nangs involved


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## Rocker1986 (27/8/13)

It's practically finished fermenting, but I don't bother taking readings in the first few days, it's just a waste of beer. I set the temp to 18 and the differential on the STC to 0.3C. I've noticed in the first couple of days of ferment, once the fridge turns off at 18, it rises to 18.3 faster, then the STC kicks the fridge in to bring it back to 18 again, then it rises again and so on and so forth. So the fridge is being switched on a little more frequently. When it gets to the end it takes longer to rise as there is obviously less activity, and the fridge doesn't kick in as often. This is because the insulated probe is measuring the brew temp. If it wasn't insulated then you would get a different temp reading to what the wort actually is.

I might do a quick reading on my next brew though and see if it is different to what the STC is reading, while actively fermenting.


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## manticle (27/8/13)

Different story if it's not active.
Fridge is acting that way because there is a source of heat in the fridge.


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## Rocker1986 (27/8/13)

Yes I figured the active fermentation producing heat would be the cause of the temp rising faster and therefore the fridge kicking in more often. It just doesn't follow any logic to me that just because it's fermenting, the probe measures the temp differently to when it's not as active, especially when it is causing the fridge to come on more often to bring it back to the desired temperature. I'm not arguing because I haven't tested it, it just seems weird. But, as I said, next brew I will take a reading while it is actively fermenting to see if the temp of the brew is the same or higher than what the STC reads. If it is higher then I'll drink a six pack of VB cans


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## JoeyJoeJoe (27/8/13)

Well they are down gentlemen.

Did two batches both the same but one kit was Morgans Blue Mountain Lager Brand new exp date 2014 and one was a coles lager exp date 2011 (long story)
I added half a can of Morgans master blend lager to each plus 500g dextrose. The Magic spread sheet said I should have a OG of 1.041 at 23L but my hydro said 1.038 but it could have been 1.036 or 1.040 depending on how you look at it ?

I ended up addid 9L of cold water to both fermenters with the tap water and the temp pre yeast was about 16C I mixed up two batches times 2 (total 4 packs) of the w34/70 let it sit for 20min gave them both a stir chucked them in the fridge for 30minutes then added them in they looked ok like really thick bread smelling milk.

Pic Blue mountain on left Coles on right the Blue was sweet then suprisingly bitter while the coles was pretty plain bit sweet not very bittter at all. I was really suprised at the different colours!


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## jotaigna (27/8/13)

That photo is a cautonary tale for kit brewers world wide.
Anyone who asks "I found this kit in me garage from 1987, should I put down a brew?" should be pointed to it.


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## GalBrew (27/8/13)

JoeyJoeJoe said:


> Pic Blue mountain on left Coles on right the Blue was sweet then suprisingly bitter while the coles was pretty plain bit sweet not very bittter at all. I was really suprised at the different colours!


Oxidation much? Seriously +1 to the above comment. Also explains your 'sweet' tasting beer. Jebus....... :unsure:


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## Ducatiboy stu (27/8/13)

Maybe over time the hop oils have reacted with the malt.

Either that or the coles tin was misslabeled..


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## Rocker1986 (27/8/13)

I was led to believe malt extracts will darken with age. That may be part of the reason for it too, given it's a couple of years out of date.


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## GalBrew (27/8/13)

Or it has been sitting in a cupboard or a LHBS shelf in the sun for the last 2-3 years and has slowly oxidised over time.


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## Ducatiboy stu (27/8/13)

Hard to oxidise in a vacume sealed tin...but anything is possible


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## GalBrew (27/8/13)

Ducatiboy stu said:


> Hard to oxidise in a vacume sealed tin...but anything is possible


So now we are saying that tins of goo don't oxide on the shelf? I am pretty sure they aren't vacuum sealed either. They are canned and probably pasteurised in an autoclave, but I have never heard telltale 'whoosh' of air enter a tin of goop upon opening. I will even reference 'the Palmer' on this one (I apologise for being lazy and not using the newest version but I am going home). 

http://www.howtobrew.com/section1/chapter3-2.html


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## Adr_0 (27/8/13)

from what I read, you should only really cold pitch if you are 100% confident you have the volume of yeast cells. a pack of dry yeast has viability but I would be a bit nervous about the cell count so would quietly be either pitching at fermentation temperature or a couple of degrees warmer... as everyone has suggested above.

The 'waiting 12hrs' is also more for signs of activity before you change the temperature to fermentation temp (presumably 10°C). I would agree with this with a warm pitch.

The cold pitching thing... I'm not so sure about it. What's wrong with pitching the correct cell count of active yeast at the temperature you will ferment?

I have just done a pils, which was 1.5L, 2.5L then 2.5L (to freshen it up, not so much for growth) stir-plated starters. 50L of 1.045, so that should have been about 1.5mil/°mL. I pitched at 8°C, waited until there was pressure in the airlock after swirling a few times - ended up being 12 or 18hrs... not at my computer so can't remember - then warmed up to 10°C.

Comments? The beer is ridiculously clean, but still has buttery notes - this is diacetyl, not DMS as I think has been confused above. Not a hint of ester. Diacetyl did get a bit stronger, but I haven't tasted since dropping to lagering temps.

I would say it is the cleanest lager I've done, but previous lagers have only had about 1mil/°mL and I would say this, then pitched at correct fermentation temp, is more important than cold pitching. Anecdotal a bit, but I haven't seen a lot of science about the cold pitching. Thought I would give it a go though.


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## JoeyJoeJoe (29/8/13)

I have been doing some more research on this topic and found this http://www.fermentis.com/wp-content/uploads/2012/06/TT_Booklet_En.pdf.

It is a bit of guide that fermentis put together anyway if you jump to page 6/7 it seems to indicate that they recommend rehydrating at 23C and then pitching the yeast into the wort when it gets to 12C. This seems like a big temperature change but I guess they know what they are up to.

I also found this graph very interesting. It really shows that yeast starts kicking the diacetyles ass when they lift the temp up to 14C (they recommend 48 hours at 12 then up to 14.)
The start time was pretty close to what I experienced as well about 24 hours before I saw air lock activity.


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## Rocker1986 (4/9/13)

Rocker1986 said:


> Yes I figured the active fermentation producing heat would be the cause of the temp rising faster and therefore the fridge kicking in more often. It just doesn't follow any logic to me that just because it's fermenting, the probe measures the temp differently to when it's not as active, especially when it is causing the fridge to come on more often to bring it back to the desired temperature. I'm not arguing because I haven't tested it, it just seems weird. But, as I said, next brew I will take a reading while it is actively fermenting to see if the temp of the brew is the same or higher than what the STC reads. If it is higher then I'll drink a six pack of VB cans



Well, it appears at least for my set up and equipment, that I was right. I have a brew in the FV which is in its second day of fermenting, quite a thick krausen (grav reading is 10 points below OG so it's going nicely), temp probe taped and insulated on the side measuring 18.2C, took a sample and took the temperature at 65F (or 18.3C). I don't know whether this is due to the way I insulate it, covering it with a reasonably thick layer of foam and taping it on with big thick plastic tape, but it's accurate.

Not saying it'll necessarily be like that for everyone, as obviously others have had different experiences, so obviously you'd set it up to suit your own situation, but at least now I can be happy in setting the thing to the temp I intend to ferment at and not worry about it going 2 or 3 degrees higher. And I don't have to drink that 6 pack of VB cans. :lol:


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## JoeyJoeJoe (4/9/13)

Thanks for letting us know.I have ordered a digital temp probe on ebay that I will be able to stick down the air lock so I will report back next time I have a fermenting brew (current one is 10 days in so very little activity).


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## Rocker1986 (4/9/13)

No worries. Yeah, that would be the most accurate way of measuring it if you can do it without risking infections and such.

I can't remember whether I have tested it on an actual fermenting brew before or not, but I will do it again on the next couple of brews as well to see if it is consistent. It just defies logic to me, which is why I decided to test it, that just because the brew is fermenting it'll measure differently. The probe is measuring the same way regardless. The fridge is coming on more often to keep it down. Now if the temperature when it's inactive is coming through the plastic accurately, it surely follows that it would come through accurately during fermentation as well, which it did today at least.


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