# Cube questions



## Noodlebrew1984 (2/11/20)

Hello! I have just joined up to the forum because alot of you over in Australia use the No-chill method 

I've just done my first attempt at No-chill. I decided to use my bittering hop at the start of the boil, but then left out all the additional flavour/aroma hops.

Then when the boil ended I let it cool down in the kettle to 80°c (it took 30 minutes) before transferring to the sanitised cube. I did this because I didn't want to pull too much bitterness from the cube hops.

I'm aware some of you will disagree with that  but my question is this... I took a gravity reading after the boil ended and it was 1060.

Then i didn't take another reading until the next day when I transferred to my fermenter. And it read 1066! So did that 30 minutes of slowly cooling actually continue to condense my wort? 

Thanks for your help in advance!

Nick


----------



## MHB (2/11/20)

No chance you got enough evaporation in that time, at least not with the fire off.
Much more likely you haven't allowed for the temperature correctly, you really need to cool the sample to 20oC (or what ever your hydrometer is calibrated at) or apply the proper corrections which is a less accurate.
Lots of online calculators, I find this one easy and has lots of other useful features Vinolab
They all depend on you knowing the temperature you are reading at accurately, always measure the temperature of the sample as well as the density.
Mark


----------



## Noodlebrew1984 (2/11/20)

Cheers mark. I forgot to mention that I use a refractomer during my mash, sparge and boil! The readings are in BRIX but I convert them over. It's an ATC refractometer, so a few drops of super hot wort are meant to cool down rapidly when you drop them onto the glass slide. 

Or am I still meant to let it cool much longer before doing that? I just wondered if the wort would continue to condense as it drops down slowly to 80°c? If not, then it has to be me taking a rubbish reading 

Who'd be a brewer hey?


----------



## kadmium (2/11/20)

Also may have been stratification when you took the cold sample. It is possible that the wort stratified when it cooled, and when you poured it into fermenter you were left with a higher gravity part at the bottom which you then checked. 

I have seen the wort separate in the fermenter pre fermentation but then the convection currents formed by the yeast mixed it all up. Just a possibility. 

Also, to gain 6 points you would have needed to evaporate another few litres. Wouldn't happen in 30m not on the boil, I don't think. 

Did you use a refrac or hydro?


----------



## Noodlebrew1984 (2/11/20)

Ah ok, that's interesting. 

I guess when you do a rolling boil, the wort is pretty well mixed given how vigorous the boil is. So any readings from the kettle during the boil or just after should be accurate depending on how accurate your hydrometer or refractomer is.

I can understand stratification occuring in the cube overnight however as its sat there for hours and hours.

However, I then poured the cube into my fermenter through a sieve, you'd think that would give it a pretty good mix prior to me then taking the OG reading? 

I used a hydro and a refrac for my OG. 

Cheers


----------



## kadmium (2/11/20)

Did you take a sample from the cube or from the Fermenter when you did the second check?

Yeah it does sound strange. A refrac needs no temp correction generally in general.


----------



## Noodlebrew1984 (2/11/20)

I took my OG sample from the fermenter straight after I had transferred it from the cube, so it should've given it a fair mix when I poured it.

The only other thing I can think of, is maybe my post boil reading of 1060 wasnt an accurate reading after all.

That was taken from the kettle at flame out with a refrac.  it's a mystery


----------



## philrob (2/11/20)

As far as I know, ATC on a refractometer doesn't mean it automatically compensates for the wort temperature you place on it. I believe it means it compensates for the ambient temperature of your environment. 
When I take my wort sample I allow it to cool down before I place it on my refractometer, to ensure I get a reasonably accurate reading.


----------



## Noodlebrew1984 (2/11/20)

Good to know. Thankyou. In future I will take a sample and let it cool down I think. I generally use my refrac for the mashing, sparging and boiling just to make sure I'm hitting the numbers, then I use a hydrometer for my OG reading.


----------



## TheAussieBrewer (2/11/20)

Be careful when transferring below boiling, the temperature at 80c isn't enough to sanitise the cube and if you plan on keeping the wort for any period of time it will have a high chance of spoiling.


----------



## sp0rk (2/11/20)

TheAussieBrewer said:


> Be careful when transferring below boiling, the temperature at 80c isn't enough to sanitise the cube and if you plan on keeping the wort for any period of time it will have a high chance of spoiling.


72c for 15 seconds is common in the dairy industry, I'd dare say 80c for a few minutes with our wort should be pretty ok, but that's just my experience with basic microbiology at uni so far


----------



## TheAussieBrewer (2/11/20)

sp0rk said:


> 72c for 15 seconds is common in the dairy industry, I'd dare say 80c for a few minutes with our wort should be pretty ok, but that's just my experience with basic microbiology at uni so far


I take it you are you referring to HTST pasteurization? In theory that should work, but in my experience transferring wort after an 80c whirlpool into a cube hasn't kept well. I have a fairly rigorous sanitation regime and still ended up with swollen cubes that where infected with an unknown bacteria/yeast (after 6 months storage mind you). I have never had an issue cubing straight off the boil.

@Noodlebrew1984 if you don't want to impart too much bitterness, try adding at flame out and transfer to the cube while they steep. Another option is to cube hop and strain the hops out when transferring to the fermenter.


----------



## Noodlebrew1984 (2/11/20)

Cheers for the replies. Yeah I have seen many of you guys talk about transferring whilst it's still almost at billing point for sanitizing the cube.

Couple of things- 

1. I was concerned with the bitterness. I did read that hop isomerization occurs above 85°c, so figured I'd go abit lower to pull the flavours and aromas and not any more bitterness?

2. The other thing is, surely if you clean everything nicely and then use starsan prior to transferring, combined with 80°c wort, the chances of bugs surviving that are quite low? 

But I definitely am still learning, so am taking everything you all say seriously. 

Cheers


----------



## TheAussieBrewer (2/11/20)

Noodlebrew1984 said:


> Cheers for the replies. Yeah I have seen many of you guys talk about transferring whilst it's still almost at billing point for sanitizing the cube.
> 
> Couple of things-
> 
> ...


Keep in mind that there is only an estimated 10% conversion of alpha acids to iso-alpha acids for flameout hops that will be put through a hop stand prior to cooling so you will be extracting very little bitterness compared to a 60 minute addition. If you are finding that your beers are turning out overly bitter (I haven't found it an issue in my experience) you can delay the 60 minute hop addition to either 50 minutes or 40 minutes depending on your preference.


----------



## Noodlebrew1984 (2/11/20)

All useful to know. I'll see how this first cube attempt goes and take notes!

As for my gravity issue. Do you think you need to take multiple readings with a refractometer to get a better overall idea? I'm wondering if only taking 1 tiny sample of wort at each stage isnt a true representation of the whole batch? 

If its the case that you're meant to take several readings and take the average and also cool it down each time, i may as well go back to the bloody hydrometer again


----------



## Noodlebrew1984 (2/11/20)

I just did an experiment by boiling up some sugar in some water and taking a refractometer reading at near boiling temperature.

I tried to look through the lens as quickly as possible, and it said 15 brix. I then let it cool for a little while longer and had another look and it was still 15 brix! 

And to be fair even when I put boiling water directly onto it, it cooled to luke warm almost instantly. So I dont think it's a temperature issue. I reckon you need to take several readings and use the average. That's my guess anyway.


----------



## TheAussieBrewer (3/11/20)

Noodlebrew1984 said:


> I just did an experiment by boiling up some sugar in some water and taking a refractometer reading at near boiling temperature.
> 
> I tried to look through the lens as quickly as possible, and it said 15 brix. I then let it cool for a little while longer and had another look and it was still 15 brix!
> 
> And to be fair even when I put boiling water directly onto it, it cooled to luke warm almost instantly. So I dont think it's a temperature issue. I reckon you need to take several readings and use the average. That's my guess anyway.


I don't think its necessary to take a lot of SG reading for every step of the process, the main readings you need are pre-boil SG and volume, post-boil SG (OG) and volume, and post-fermentation SG (FG). The volumes will help analyse you extract and brewhouse efficiency and as long as you calibrate the refractometer with distilled water prior to use (you should do this every brew day) and you are comfortable relying on the reading you shouldn't have to check more than twice if you think you got a bad reading. Just make sure the pre-boil wort is mixed well.

If you can't trust the refractometer you can always use the hydrometer, keep in mind that if you use a refractometer for any SG readings after fermentation has already started you will need to adjust your reading to account for the alcohol (Refractometer Calculator - Brewer's Friend)

The thermal mass of the refractometer will do a great job of cooling the ~0.5ml sample


----------



## Noodlebrew1984 (5/11/20)

Yeah, eventually I'd like to not have to worry. Trouble is, I'm finding I've been overshooting my OG each time. So I'm trying to measure at each step to make sure I'm on course. 

On this occasion I appeared to have my pre-boil numbers right. Then some witchcraft happened and the next day I go to pitch and my OG is 6 gravity points higher! So I was trying to retrace my steps and was concerned my refractometer measurements were wrong. I may end up ditching it and just using a hydrometer at this rate!

Then the final variable is yeast! I've been using US-05 on each of my last few brews. I am finding it waaayyyyy too efficient at eating the sugars! I mean take this current batch... it's meant to be 1060 OG and 1014 SG... but I had 1066 and it's currently now sat at 1012. 

So another 7% + beer for me to try and session


----------



## fdsaasdf (5/11/20)

If you are having issues going over gravity, you can try diluting (on brew day or at pitch time). On brew day you can then run off enough to collect wort for starters; and at pitch time you can get a larger batch size for your efforts.


----------



## Nullnvoid (6/11/20)

Currently fermenting a cube that is 4 years old. Smelt as fresh as the day it went into the cube.

Can't wait for all that botulism!


----------



## kadmium (6/11/20)

Nullnvoid said:


> Currently fermenting a cube that is 4 years old. Smelt as fresh as the day it went into the cube.
> 
> Can't wait for all that botulism!


It's fine. Pretty sure you'll only know when you don't wake up....


----------



## Noodlebrew1984 (6/11/20)

fdsaasdf said:


> If you are having issues going over gravity, you can try diluting (on brew day or at pitch time). On brew day you can then run off enough to collect wort for starters; and at pitch time you can get a larger batch size for your efforts.



Yeah I actually did dilute pre-boil. I took it above 27 litres (which was my target volume) to hit my numbers, then mixed it well and took another reading. When I got the pre-boil numbers right, I scooped out the excess to bring it back down to 27 litres. But like I say, something is amiss with my readings  

As for my issue with US-05. It makes no difference if I re-hydrate the packets or if I just sprinkle them in, it always over ferments! 

Is this just what US-05 does, or am I pulling too many fermentables from my mash? Should I mash nearer to 70°c next time? 

Cheers


----------



## Noodlebrew1984 (6/11/20)

Nullnvoid said:


> Currently fermenting a cube that is 4 years old. Smelt as fresh as the day it went into the cube.
> 
> Can't wait for all that botulism!



That is cool as ****. It excites me about being a fellow cuber now


----------



## fdsaasdf (7/11/20)

Noodlebrew1984 said:


> Yeah I actually did dilute pre-boil. I took it above 27 litres (which was my target volume) to hit my numbers, then mixed it well and took another reading. When I got the pre-boil numbers right, I scooped out the excess to bring it back down to 27 litres. But like I say, something is amiss with my readings
> 
> As for my issue with US-05. It makes no difference if I re-hydrate the packets or if I just sprinkle them in, it always over ferments!
> 
> ...


I have never had an issue like you describe with US-05 over-attenuating - it's the most consistent yeast I've used and I stick to it for anything needing a clean neutral flavour. 

I wonder if you might have a calibration issue somewhere with volume or grain weights; or a process issue with your brew design / efficiency calculations...


----------



## Paddy Melon (31/7/21)

Hi guys, I couldn't find what I was looking for so here I am. My question is when a wort is made and placed into a 20 litre cube then stored for a month until ready for fermentation, can additional water be added to the fermenter at that time to bring it to 25 litres? I don't see a problem with this but have no idea if it may affect the brew.


----------



## MHB (31/7/21)

Sure, in fact many if not all the fresh wort kits on the market say they can be brewed as is for higher alcohol/flavour or diluted. There really isn’t any difference between a homemade "cube" and a FWK.
Just remember that your water needs to be clean, chlorine free and ideally sterile, if you wanted to dilute post fermentation add oxygen free to the list.
Mark


----------



## Paddy Melon (31/7/21)

Thanks Mark, much appreciated.


----------



## blacktop™ (12/8/21)

MHB said:


> Sure, in fact many if not all the fresh wort kits on the market say they can be brewed as is for higher alcohol/flavour or diluted. There really isn’t any difference between a homemade "cube" and a FWK.
> Just remember that your water needs to be clean, chlorine free and ideally sterile, if you wanted to dilute post fermentation add oxygen free to the list.
> Mark




Oxygen free H2O? Is there such a thing?
It kinda…wouldn’t be water?


----------



## fdsaasdf (12/8/21)

blacktop™ said:


> Oxygen free H2O? Is there such a thing?
> It kinda…wouldn’t be water?


I am no scientist but I presume MHB is referring to the water being free of excess Dissolved Oxygen, or having oxygen in the headspace of the container.

Not all water is equal - unless completely demineralised it contains various other elements like calcium - and the proportion of oxygen varies greatly which has significant impacts to chemical and biological applications. For example, boiling is a technique used to reduce the oxygen content in water. Doing so reduces the DO which is a key factor in avoiding/slowing the spoiling of beer (and preserving food, and scientific experiments, and many other things).


----------



## blacktop™ (13/8/21)

I totally agree.

I just didn’t know that diluting post fermentation was even a thing.
It’s risky to say the least lol


----------



## MHB (13/8/21)

Not all that uncommon in commercial brewing. There are issues with brewing at too high a gravity (yeast stress for one) but you can make more beer in the same sized equipment.

As fadsaasdf said we are talking about "Dissolved Oxygen" in post fermentation dilutions. Boiling will reduce DO but bubbling Nitrogen through the water is cheaper on a large scale (just like an Air Stone for adding O2 to wort pre ferment), for all the reasons he gave above. N2 doesn’t sterilise like boiling would.
Mark


----------



## chrisfromperth (13/8/21)

blacktop™ said:


> Oxygen free H2O? Is there such a thing?
> It kinda…wouldn’t be water?


LOL. Yes, it would be hydrogen 

They mean dissolved oxygen. Water that comes out of the tap has about 5 parts per million oxygen. Well-aerated water, up to 15ppm. It doesn't sound like much, but it's enough to react with beery good things and let them start to taste stale. Unless of course we're about to pitch a starter. Yeast will consume all of that oxygen and more as they go through their growth phase.


----------



## mynameisrodney (13/8/21)

I've only diluted post fermentation once, but it was the fastest oxidising beer I've made by a factor of about x10. Will not be doing again.


----------



## yankinoz (13/8/21)

MHB said:


> Not all that uncommon in commercial brewing. There are issues with brewing at too high a gravity (yeast stress for one) but you can make more beer in the same sized equipment.
> 
> As fadsaasdf said we are talking about "Dissolved Oxygen" in post fermentation dilutions. Boiling will reduce DO but bubbling Nitrogen through the water is cheaper on a large scale (just like an Air Stone for adding O2 to wort pre ferment), for all the reasons he gave above. N2 doesn’t sterilise like boiling would.
> Mark



There's always Campden tablets. Added after bringing water to a boil the needed amount would presumably be 1/5 of that needed to deoxygenate cold water. See How much disolved oxygen is removed by boiling water? 

Obviously more would be needed if chlorine is also present.

Re commercial brewers I read that Coors brews to 7 1/2 percent and dilutes to reach either their main brand (4.6% abv?) or their Lite.


----------



## MHB (13/8/21)

To save 1000 words





Link Engineering Tool Box
All brewing liquor should be pottable water and Chlorine free, take that as a given. 
Mark


----------



## Coalminer (14/8/21)

Why not dilute pre-fermentation?


----------



## yankinoz (14/8/21)

MHB said:


> To save 1000 words
> View attachment 120961
> 
> Link Engineering Tool Box
> ...


Point taken. Cancel the Campden tabs, though they might be useful to take up oxygen if one cools the water and then pours it in an aerating fashion.


----------



## MHB (14/8/21)

Perhaps, would be pretty silly thing to do.
Just no-chill any diluting water, if you treat it like a no-chill wort it will be fine. Would be worth finding some Jerries around the size you expect to use as obviously once opened it wouldn’t be sterile or O2 free for long.

Coalminer
It isn’t something I do often or recommend, but for commercial brewers if you took the example Yankinoz mentioned. Diluting from 7.5% to say 4.6% means you can make 63% more beer in the same fermenter and big SS fermenters aren’t cheap... The big boys are using antifoam agents to cram even more into their fermenters; some are filling to 90%. Have to think it's more about $'s than flavour.
If you have the fermenter volume, for sure I think you will make better beer and more of it by diluting before fermentation. You are taking les risks with oxidisation, infection or contamination to, so feck yes dilute first if you can.
Mark


----------

