Fermenting Double Batch By Adding Batch 2 After A Day Or Two?

[BjornJ]

Hi all,
hoping for some feedback around brewing and fermenting a double batch.

Considering getting a 60 litre fermenter and make a big batch of lager for summer.

Will this work?

1.Brew 25 litres of beer, cool and pitch yeast.
2: Brew 25 litres of beer the next day, cool and add to fermenter.
-straight away?
-after a couple of days?


My thinking is that rather than have to double the yeast starter size which is already 3-4 litres as well as stress with brewing twice in a day while the first batch is in the fermenter, can I just add another batch after a day or two?

I think this would work, just like adding sugar after some days.

Is this a good idea or are there problems I haven't thought of ?

thanks
Bjorn

 

[manticle]

I won't comment on the brewing science aspect of it but I have added various things to my fermenting beer over time and it's worked more often than it hasn't. These include sugars like malt, candi or lactose, yeast and wort.

It seems to make sense that if you are trying to avoid stressing the yeast that you would wait until it kicks off and has grown before adding in more wort rather than just chucking in the next day.

Obviously avoid oxidising your already fermenting beer.

 

[Zwickel]

No worries mate, that certainly will work. :icon_cheers:

 

[BjornJ]

thanks guys, but as Manticle touched on,
is there a danger of letting the beer ferment for a day or two, then add another airated batch?
(thinking the yeast has gone through the growth phase and really not appreciate the airated wort)

Guess I am not sure if this will make the yeast grow more or just oxidise the beer.

Will it be better to add the second batch the next day to add it as fast as possible while the yeast possibly still can use the oxygen, or better to wait several days/a week and then add the the second batch to let the yeast continue eating.
If waiting I could even just add it from a No Chill cube without airating it?


Lots of questions, I know, just thinking out loud here

thanks
Bjorn

 

[manticle]

Just don't aerate the second batch. Aeration is to help the yeast grow - you've already done that and she's away so add the next lot in gently.

 

[MHB]

I remember putting nearly the exact same question to a brewing consultant yonks ago, was strongly advised not to.

Even un-aerated wort contains lots of fractions we want the yeast to metabolise; during the reproductive phase the yeast stores lipids and glycogen (among other things), removing them from the wort, which improves the beer and prepares the yeast for the job of fermenting the sugars in the wort we both win.

If you keep introducing fresh wort the yeast can sort of re-boot, switching back to vegetative state then back to making alcohol.

It ends up very stressed and generally fails to do any of its jobs well

Much better to get the right sized pitch into the wort at the start.

MHB

 

[Zwickel]

thanks guys, but as Manticle touched on,
is there a danger of letting the beer ferment for a day or two, then add another airated batch?

No problem, oxydising is only an issue when the wort is hot. The yeast is going to consume the oxygen immediately.

(thinking the yeast has gone through the growth phase and really not appreciate the airated wort)

no, no, the yeast will be very happy about the oxygen and will boost its growth as long as there is sugar available.

Will it be better to add the second batch the next day to add it as fast as possible while the yeast possibly still can use the oxygen, or better to wait several days/a week and then add the the second batch to let the yeast continue eating.
If waiting I could even just add it from a No Chill cube without airating it?

Id recommend you to add the second batch within 3 days.

Cheers :icon_cheers:

 

[manticle]

Have you tried it though MHB? I was under the impression from one of the brewing network shows that at least one trappist brewery follows exactly this method (brew pitch, brew again and add).

I must admit when I've added wort to fermenting beer it's been in much smaller amounts than suggested above (might have missed target gravity or felt the beer was too thin or whatever) but in my (limited) experience it can work.

Not trying to question your expertise - brewing has many answers and not 100% of them seem 100% right or 100% wrong, 100% of the time. Hence why I'm interested in it.

Personally I agree - if doable get the starter right in the first place but you have to factor in that his system will only do one batch at a time so he's trying to brew over a couple of days.

I guess the other solution is to cube both while you grow the starter.

 

[Zwickel]

This method is a common practise over here in Germany, we call that "Drauflassen", have a look here: http://www.braukaiser.com/wiki/index.php?title=Drauflassen

:icon_chickcheers:

 

[Screwtop]

Visited a NSW craft brewery in 2008 where this double batching practice was observed.

Screwy

 

[Ross]

Very common practise in breweries & no negative effects that I'm aware of...

Closer to home, Mt Brewery on Tamborine uses this method on most brews.


Cheers Ross

 

[MHB]

No its not something I have tried; I always brew to match my fermentation capacity so there has never been the need.

Will have to look into the idea further tho I have honestly never been in the situation where its become necessary.

MHB

 

[mxd]

just sounds like a nice big starter to me.

 

[jimi]

Very common practise in breweries & no negative effects that I'm aware of...

Closer to home, Mt Brewery on Tamborine uses this method on most brews.


Cheers Ross

I recall Gerard telling me this was a standard practise he used at Paddys too - check out the fermenting and boil volumes your savvy micros have and you'll see plenty of evidence for others setting themselves up to be able to do this too

 

[fcmcg]

Wow..see this is why I love AHB..this is some fantastic information .and thanks Zwickel for the link.I am going to try this for my next double brew . I'll no chill the first lot , out my 40 liter brew , and then put the rest into my 60 liter feementer and pitch a normal amount of yeast for the brew. This means I won't need to make a massive starter too !
Cheers
Ferg

 

[Thirsty Boy]

You don't want to drop the starter size too much ferg... You absolutely can start with less yeast this way...but I don't think your are talking a halving or anything like that.

If you needed a 4L starrter for the full batch, this might well let you get away with a 3L starter, but I don't think splitting your wort addition in 2 is going to let you halve your starter size.

Remember, in a starter (one designed to increase cell count) you are optimizing conditions to give you maximum growth of healthy viable yeast.... In this method, your yeast might be going into half the wort initially - But the conditions in your fermenter are about making good beer... Not about growing good healthy yeast.

For mine, this is a technique you use to overcome a limitation in your set-up. Absolutely can't grow a big enough starter? - Ok, this is an option. Want to brew and ferment a big batch, but only have brewhouse capacity for a small batch? - ok, then this is an option. But except for curiosity's sake - then there is no reason to do it if you don't have a limitation to overcome.

 

[bum]

For mine, this is a technique you use to overcome a limitation in your set-up. Absolutely can't grow a big enough starter? - Ok, this is an option. Want to brew and ferment a big batch, but only have brewhouse capacity for a small batch? - ok, then this is an option. But except for curiosity's sake - then there is no reason to do it if you don't have a limitation to overcome.

So in balance, would you say it would be better to follow the proposed method or cube the first day's brew and pitch the lot at once?

 

[Thirsty Boy]

I'd cube the first days, then pitch the lot at once. Assuming you grew an appropriate starter for the full volume. but it would depend on the beer and whether cubing itself was going to present an issue. If you were just adding the next batch of wort the next day.. I doubt it would make any discenable difference either way.

That's one of the things I really like about no-chill... It opens this sort of stuff up, and renders it unnecessary - in almost equal measures.

 

[Nick JD]

Drink Dominion Breweries (DB) products. I think adding wort to an active ferment is essentially a simple version of Continuous Fermentation.

 

[Thirsty Boy]

Case in point Nick. DB breweries is one of, in fact maybe the only - commercial brewer using continuous fermentation. Perhaps the chief reason this is so (among a bunch of reasons to be fair) is that most breweries who tried continuous fermentation, simply could not match the flavor profiles of their brands that were traditionally batch fermented.

So.. To draw a relatively long bow on the comparison.... You can add more wort to your active ferment, a lot, two lots, a dozen lots or continuously. But the beer that comes out won't really be the same as it would have been if you batch fermented normally. Not necessarily worse, not better.... Just not the same.