3rd Biab Attempt

[Truman42]

Had a crack at my third BIAb tonight, A black IPA. I did a MaxiBiab so used the maxibiab calculator.

My start of boil SG was 1.076 and end of boil Sg was 1.067 the calculator said to add 3.3 litres of water to dilute down to 1.060 so I added 3.3 litres of boling water into my cube. Last time I added cooled boiling water the next day but thought it would be better to add boiling water while the wort was still hot.

I still only ended up with 17 litres in my 20 litre cube, and have a big air gap at the top because I couldnt squeeze much out.

Is this going to be a problem having so much airspace?



Also with my first BIAb I had a very succesful whilrpool and all of the hotbreak ended up in the middle of the pot so very little made its way into my cube. With this one and my last Batch I used irish Moss 1/2 tablet and did a really good whilrpool but still had a lot of hotbreak spread out all over the surface and a fair amount made its way into my fermenter.

What am I doing wrong here? Any tips on preventing this?

 

[Tanga]

Quick, flip it upside down and sterilise the top half too.

 

[Truman42]

Quick, flip it upside down and sterilise the top half too.

Thanks Tanga, just ran down stairs and did that. I left it upside down for a couple of minutes, is that enough?
Just to add I did sanitise the cube with defender and rinsed with boiling water before filling just to be safe.

 

[Tanga]

Sorry, I am pretty new too, as long as it touches all the surfaces for a few minutes it should be fine.
Sounds like you did the right thing. Don't know anything about Irish Moss though, sorry. Less can be more with flocking agents though, apparently, there was a thread recently.

 

[bignath]

Hey truman, it sounds like you may have something not quite set up properly...

Are you brewing with some kind of software?

If you are getting 17lt AFTER adding an additional 3+lt and were expecting 20lt into the cube then somethings not right.

I cant help thinking that if you are falling short of volume, but too high with gravity then you may need to do a quick sparge.

This should give more volume and help to correct the overshoot of gravity of your wort.

 

[Florian]

My start of boil SG was 1.076 and end of boil Sg was 1.067

How does that work? Have you got your numbers mixed up?

because I couldnt squeeze much out.

Why not?? Place your cube against a door frame or something similar where you can hold on to, preferably on a towel, open the lid slightly and press with one foot against the cube until almost no air is left, then close the lid. If you want to you can then tilt the cube sideways so the air bubble is right under the lid and repeat the process until there is literally no air left in your cube.

EDIT: Oh, and don't do this barefoot...

 

[Spork]

If you are going to pitch the yeast as soon as it has cooled enough / next day don't worry too much about the headspace. If you are storing for a length of time, worry about the headspace.

 

[hbnath]

Kinda OT but kinda not....

My first BIAB had a similar nice cone after whirlpool, and on my second I used Koppafloc and ended up with the same result as Truman has in his pics! :angry:
Anyone have ideas about why it happens or is this what finings like this do? If so, I won't be using them again...it caused all sorts of headaches!

 

[Truman42]

Hey truman, it sounds like you may have something not quite set up properly...

Are you brewing with some kind of software?

If you are getting 17lt AFTER adding an additional 3+lt and were expecting 20lt into the cube then somethings not right.

I cant help thinking that if you are falling short of volume, but too high with gravity then you may need to do a quick sparge.

This should give more volume and help to correct the overshoot of gravity of your wort.

Nath,

Im using the MaxiBIAB calculator and Brewmate (but mainly for the timers) The MaxiBiab was actually very close to what I got. I didnt actually expect to get 20 litres.

I did a high gravity brew as I only have an 18 litre urn and wanted to bring my volumes up afterwards. I expected to get around 1.07x at SOB. I sparged twice and added the second sparge in stages in the last half hour to top up for evaporation.

 

[user 10246]

What were your water volumes? Did you check them pre & post boil?

I know with my pot being quite round as opposed to tall & skinny, I get quite a high evaporation rate.

EDIT: Info came at the saem time as my post

 

[Truman42]

How does that work? Have you got your numbers mixed up?



Why not?? Place your cube against a door frame or something similar where you can hold on to, preferably on a towel, open the lid slightly and press with one foot against the cube until almost no air is left, then close the lid. If you want to you can then tilt the cube sideways so the air bubble is right under the lid and repeat the process until there is literally no air left in your cube.

EDIT: Oh, and don't do this barefoot...

No numbers are right. As I was advised in another thread because I had 4.7 kgs of grain it would be hard to sparge and Im guessing that my sparges reduced my Sg whilst adding volume and therefore lowered my SG during the boil. Which was fine as it needed to be 1.060 at EOb anyway. Is that what may have happened??

I did squeeze the cube up against a wall with my knee but these cubes seem to be thicker plastic than the wort cubes I usually use and couldn't squeeze all that much.

I'm pitching my yeast tonight anyway.

One thing I'm curious about is when you release the cap to let some air in then shake to aerate before pitching the yeast. Doesn't letting air in also let in some unwanted bacteria?

 

[manticle]

See Florian's post Truman. Post boil grav should be higher than preboil.

Also should be able to squeeze much more air out - just use your knees. If the cube is too hot, put towels or oven mitts between knees and cube.

 

[Truman42]

See Florian's post Truman. Post boil grav should be higher than preboil.

Also should be able to squeeze much more air out - just use your knees. If the cube is too hot, put towels or oven mitts between knees and cube.

Could the sparging have reduced my EOBG as I added it during the boil to allow for evaporation? It was hard to get a good sparge with the 4.7 kgs of grain I had and as Nick commented in another post that I wouldn't get very good efficiency with this much grain. So all I can think is that my sparge water added more water than sugars and thinned out my wort which lowered my EOBG.

Does that make sense? I checked my Sg in the cube after adding 1.5 litres of boiling water just to make sure that the figure maxibiab calc told me to add of 3.3 litres was on track, and it had dropped to 1.063. (Adjusted to 20C)

 

[Truman42]

Also...When I was draining into my cube I lifted the lid on the urn and noticed what looked like vapours rising from the wort in various pockets on the surface.

It wasn't steam, it looked more like cigarette smoke, if that makes sense, and it was just sort of rising slightly in small pockets around the surface of the wort.

Ive never seen this before.

 

[esssee]

Trueman,

I think your right when you say that adding the Sparge to the boil in stages has reduced your Post Boil Gravity to below that of your Pre Boil Gravity.

One of the problems I can see doing it this way is that your hop additions will be off, and you could UNDER hop compared to what you are expecting.

 

[QldKev]

You measure pre boil gravity once all the water/wort is in the kettle.
Nothing wrong with measuring first runnings etc, but they are not a pre boil reading.


If you ended up under volume at your target gravity, then you have not hit your target efficiency.



QldKev

 

[beerdrinkingbob]

Hi Truman,

I would say the difference from the reading is because you actually increased your volume when you topped up.

All things being equal, if you were able to boil it back to the exact same volume you would have a higher gravity reading.

Cheers BDB

 

[RdeVjun]

It looks like a fairly typical MaxiBIAB to me, so I'll explain how I see that it unfolded. The start of boil SG Truman mentions was actually the first runnings at 1.076, that's about right for the grainbill and mash volume you can get in the 18L urn, while the volume should've been around 10 to 12L. During the boil Truman added some sparge liquor, depending upon the sparge volume it usually has an SG of about half the first runnings, maybe less and I'd say at least 4L of that went in, then some boiling water was added to the cube upon filling. So it has been diluted to the precise target OG, this is normal with MaxiBIAB/ high- gravity brewing where the kettle volume is limited, although I dilute in the fermenter at pitching as pouring the water in vigorously helps aerate the wort.

Truman, one reason to have the kettle full as possible at draining is that the kettle trub losses in terms of proportion of fermented beer volume are lower, that is achieved either by adding more sparge liquor during the boil or by adding boiling water prior to flame out. You ordinarily leave a fixed volume in the kettle, by diluting as much as possible that remaining wort is of a lower concentration, hence less mass of sugars lost to kettle trub. Its not a huge difference but with this method every bit adds up.

As noted, these larger grainbills aren't earth- shatteringly efficient with MaxiBIAB, however I think this was a great job on Truman's behalf, I myself did an English IPA a few weeks ago with 5.3kg in a 19L pot that yielded 21L of 1.058 in the fermenter (74% efficiency), although it was triple mini- sparged*. Here's the data if anyone is interested:
Step Volume(L) SG
1st Runnings 9.9 1.084
1st Sparge 3.8 1.053
2nd Sparge 4.2 1.034
3rd Sparge 2.4 1.034
Post- boil ~17L 1.072

As far as questions in Truman's OP go, I'd be careful with kettle flocculant such as Irish Moss, Whirlfloc, Koppafloc etc, don't be tempted to overdo it as less is often more. But don't be overly concerned if some hot break (or any kettle trub for that matter) makes it into the cube/ fermenter, it isn't quite the big bad beer- wrecking bogeyman as is often made out. IMO so long as the majority of hot break and hops debris is excluded from the fermenter then all should be well. Cold break is effectively harmless.
The airspace in a partially- filled cube is no problem, should be fine.

Pardon the essay but I hope that helps! :icon_cheers:

* Tip for MaxiBIABers- a double mini sparge seems to work quite well if you can be bothered, around 3 or 4L each time, it also helps to make sure it is slightly acidic too. I also find the quasi- batch sparge, i.e. placing the still- bagged lautered grain in a bucket, pouring in the hot (i.e. near boiling) sparge water and stirring it through, then lifting the bag to lauter, works a little better than plain dunk sparging, but there's really not that much in it. For a 4-5kg grainbill if your sparge vessel is <12L then you may have to do it in two steps anyway.

 

[pk.sax]

You measure pre boil gravity once all the water/wort is in the kettle.
Nothing wrong with measuring first runnings etc, but they are not a pre boil reading.


If you ended up under volume at your target gravity, then you have not hit your target efficiency.



QldKev

what he said. Don't know of much wrong with adding the sparge water late into the boil as long as its not that much volume. But the bre-boil gravity is what you have after all the sparging is done. If you are amending a set process you have to discount set formulae and figure the changes out.

 

[Truman42]

Trueman,

I think your right when you say that adding the Sparge to the boil in stages has reduced your Post Boil Gravity to below that of your Pre Boil Gravity.

One of the problems I can see doing it this way is that your hop additions will be off, and you could UNDER hop compared to what you are expecting.

The maxibiab calc gives you your hop additions based on your expected volume into fermenter including water additions.