Cube questions

[Noodlebrew1984]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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

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]

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]

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]

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]

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]

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]

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!