Mash volume to large for kettle

Post #1 made 9 years ago
Hey guys my mate and i are going halves in some ingredients for a brew but i have a problem, Biabacus tells me that i can't fit all of my liquor & the grain in my keggle for the mash. The last time i did a large batch (35ltrs)i substituted some base malt with some DME to make it all fit, this time i want to make it all grain though. My brew pot is a keggle on a gas burner and i will be no chilling into 2 x 16.3ltr cubes.
I have come up with 2 options of doing it so far which are as follows;

option 1; withhold about 10-11ltrs of strike water, dough in and then top up the keggle with as much as will fit for the mash then add the remainder after the 90 min mash before the boil.

option 2; withhold about 16-17ltrs (in my Big W pot) and mash with the rest in my keggle. When the 90 min mash is finished i could have the 16-17 ltrs heated to mash out temp and placed into my esky with ball valve (no false bottom or braid). Then transfer the grain bag into the esky for a dunk sparge (if thats what it is called), a good stir and a little rest then transfer the sparge water to the keggle via silicon hose attached to both ball valves and on to the boil.

I can try to post both Biabacus files if it helps. At the moment i'm thinking that option 1 would be the best as it would require less work/time during the process/clean up and it seems that Biabacus compensates with more grain in order to hit the same OG anyway.

Any thoughts guys?

Post #2 made 9 years ago
Seeing your BIABacus would definitely help.
10-11 litres sounds like a lot to hold back, but without knowing what else you are doing makes it difficult to advise.

I presume you have used section W (Full Volume Variation) to calculate your volumes?
G B
I spent lots of money on booze, birds and fast cars. The rest I squandered
I've stopped drinking, but only when I'm asleep
I ONCE gave up women and alcohol - it was the worst 20 minutes of my life
    • SVA Brewer With Over 100 Brews From Great Britain

Post #4 made 9 years ago
Hi Dazzbrew,

Sorry I haven't replied sooner, been ill.
Anyhow, I have looked at option 1 (only) at the moment. Is your kettle really 47 Litres?
If so, you may be able to dilute with less water here. Ideally you want to get your mash volume as close to maximum as possible with a little headroom & breathing space that is safe to operate.
Doing so will expose your grain to more water, increasing your kettle efficiency, & thereby reducing the amount of grain required.
As an example, your 10.95 Litres added after boil means you need 8146g of grain. If you change this to 9 Litres you will now require 7970g of grain. 8 = 7891g etc. etc.

6.35L added after boil is your minimum addition by having a mash volume right at the lip (which you wouldn't want to do by the way). If you are confident of your kettle volume, then 8L added after the boil seems sensible to me, as this equates to about 20% dilution, any more than this and you may have an adverse affect on the beer (who knows)?

The only other thing worth mentioning is get yourself a hopsock. Basically just use another brew bag or make your own out of voile.
If you look at section G - Hopsock (y/n), change your "N" to "Y" and see how much more headspace you will have now. Using a hopsock means there will be less water loss when you remove them (advanced trub management). By using a hopsock you could reduce the water addition from 8L to 4L (& your grain bill is 7258g) a saving of nearly 1 kilo! :shock:
Although this is pretty close to the lip so probably better to up that a little.

So in summary; How confident are you of your kettle volume? can you use a hopsock?
Finally, you have also made some alterations to section X for kettle shape adjustments. I have never used this so have no experience here, but I just wondered how accurate these were?
Last edited by mally on 12 Dec 2014, 03:29, edited 1 time in total.
G B
I spent lots of money on booze, birds and fast cars. The rest I squandered
I've stopped drinking, but only when I'm asleep
I ONCE gave up women and alcohol - it was the worst 20 minutes of my life
    • SVA Brewer With Over 100 Brews From Great Britain

Post #5 made 9 years ago
mally wrote:Hi Dazzbrew,
Ideally you want to get your mash volume as close to maximum as possible with a little headroom & breathing space that is safe to operate.
Doing so will expose your grain to more water, increasing your kettle efficiency, & thereby reducing the amount of grain required.
Hey Mally, I hope that you are feeling better mate.
I totally agree with your comment above and if you re read my initial process described in option 1 (original post) you will see we are on the same wavelength :thumbs:

I was intending to add the grain and as much water as possible then add any water that doesn't fit into the mash to the keggle straight after the bag is pulled BEFORE the boil.
Last edited by Dazzbrew on 12 Dec 2014, 16:18, edited 2 times in total.

Post #6 made 9 years ago
Yep Dazzbrew, I was merely pointing out the calc side of things as knowing how much you can add before the grain goes in will allow the software to calculate your strike temp more accurately.
It probably wouldn't make a huge difference but there would always be a slight risk of missing your desired mash temp otherwise.


:luck:
G B
I spent lots of money on booze, birds and fast cars. The rest I squandered
I've stopped drinking, but only when I'm asleep
I ONCE gave up women and alcohol - it was the worst 20 minutes of my life
    • SVA Brewer With Over 100 Brews From Great Britain

Post #7 made 9 years ago
Ahhhh, righto Mally, i only mentioned it because you said after the boil,thanks for clearing that up :) I never considered the strike temp and I new that the grain bill changed depending on volume of water in the mash. My thinking was that if I entered that I was withholding 10ltrs from the mash but in practice was only withholding 8ltrs then all that would happen was that I would maybe overshoot my OG by a smidge.

Since your prompting I have re measured my keggle and updated section B and section X of my Biabacus. Not only did I re measure it but I filled it using my calibrated Big W pot (calibrated by headspace measurement every 500ml). With my measured water additions I came up with 48ltrs full to the brim. When I entered my measurements into Biabacus it came up short in volume, due I think to the fact that my keggle has 2 raised ridges running around it. To remedy this I kept the diameter measurement of the keggle accurate (because this affects evaporation figures) as well as those in section X BUT to get it to read 48ltrs (as per my real life volume measurement) i increased the height measurement in section B by 17mm until it showed 48ltrs.

yes I can, and have this afternoon purchased a hop sock, I think that I will use a glass marble in it with the hops to keep them down in the wort during the boil.
Dazz.

Post #8 made 9 years ago
Ok, on to the next small problem, when I selected Y for hop sock I noticed that my most important volume has changed (decreased), that volume is VFO. This is the most important volume measurement for No Chillers and the one area that the Biabacus falls down. As you know the volumes in section K are set out chronologically (as you read down wards)for a brewer who uses a chiller BUT for those of us who no chill KFL (in our case Kettle to Cube Loss) comes before VAW as we leave HOT waste (trub and hop matter) behind in the kettle.
As a no chiller we are not concerned with the actual VIF figure in section B, what we need to do is set it so that we get the desired figure for VFO in section K. We no chillers need to make sure that this figure (VFO) is equal to/more than the volume of our no chill cube + the kettle loss to trub/hops.

Post #9 made 9 years ago
The whole issue of how to enter hops as a no chiller into Biabacus is a bit iffy for me at the moment.
The problem being that the amount of hops entered as boil hops should affect the volumes in section K, in my case i have entered some hops as 10min additions although these will actually be cube hop additions. If I entered them as 0 min hops instead (to more accurately reflect what was actually in the kettle) then it would throw out my hop quantities for the 60min addition and my beer would be over hopped as near boiling temp hops in a cube still isomerise right? until the temp drops to a certain level. :scratch:

Post #10 made 9 years ago
Im not sure I follow you on this Dazzbrew. :scratch: On your original file with 8L added;

If you select "N" to hopsock you will have 36.05L VAW (which happens to be the most important measurement) with 5.15L of KFL (trub)
If you select "Y" you will have 34.3L VAW with 3.4L KFL.
The only real difference between these 2 worts if done separately is the amount of trub (even though the "no hopsock" had to use more water and grain to get there).

If your cubes are solid I can see why you might want to get your VFO value exact to remove headspace. But with normal cubes, as long as the VFO is less than the cube, you can just squeeze the air out and cap it.

I have only just noticed your hop query too. This hss been mentioned before, see here. Or maybe Mad Scientist or Rick and comment on that for you?
Last edited by mally on 12 Dec 2014, 19:12, edited 1 time in total.
G B
I spent lots of money on booze, birds and fast cars. The rest I squandered
I've stopped drinking, but only when I'm asleep
I ONCE gave up women and alcohol - it was the worst 20 minutes of my life
    • SVA Brewer With Over 100 Brews From Great Britain

Post #11 made 9 years ago
That's ok Mally, thanks, i'm all sorted now, I just freaked out :o because my volumes dropped when I selected Y for hop sock and I wasn't sure that there would be enough wort left at flame out to fill my 2 x 16.3 ltr cubes and leave the trub/hot break etc behind in the kettle. Obviously when using a hop sock there wouldn't be as much waste left in the bottom of the kettle :idiot: .
To me it seems much easier to leave all the waste in the kettle (even if it means a little more grain and water is needed) than drain the kettle completely (tranfering trub to the cube). That way i can empty the entire cube into the fermenter and not have to worry about syphoning off and leaving trub (taking up space) in the cube. Maybe my process is a little different from other no chillers so i should apologise for speaking on their behalf in previous posts, sorry about that.

And yes i do understand the importance of VAW when copying a recipe from another source, i understand the interplay of a certain volume of wort made from a certain grain and hop bill will result in a certain volume of wort with a certain gravity and bitterness level.
However once that recipe (or one of my own design) is entered into Biabacus, with my no chill process from flame out to fermenter i really don't need to know what my actual VAW figure would have been. And i use the term `would have been' deliberately because of what that term actually means for my process, it means a volume of (measured at room temp); whatever volume the contents of my cubes shrink down to the next day + whatever the volume is of the wort i collected in a glass jar for hydrometer sample shrinks down to + whatever the waste trub/hop filled wort tipped down the drain or into the garden shrank down to.
What's more important to me for my process is that i hit my VFO target and that at that target volume there is enough to fill my cubes without transfering any trub with it. That was my point with the comment about there being no `kettle to cube loss' field, Biabacus cant tell me how much volume of hot trub/hops will be left at the end of the boil. All i can do is make a guess based on past brews or take the KFL figure and plug it into the `Water/Wort Expansion and Contraction' tool on the unit conversion page of Biabacus.

Thanks for the link about the hop question also, it looks like I was pretty close by entering my cube hop additions as 10mins. Thanks for the tips Mally :thumbs: i'm looking forward to brewing this weekend and using a hop sock for the first time, it should be good.

Post #12 made 9 years ago
The volumes/grain amounts drop when using a hop sock, simply because you don't need to make as much beer to hit your volumes. The end VFO result is the same.

We calculate VAW exactly how you described, adding up the individual volumes is the most accurate way we know to measure. I also generally ignore this, once I get repeating VIF for a new recipe. Estimated VFO is generally what I pay most attention to, when I'm comfortable with a recipe.

12 minutes is what I have been using for 0m hop stand additions, but lately over time I am convinced that 10m(or less) might be a bit more accurate. Not very important anyway, really ... as IBU formulas aren't really supposed to be accurate anyway. I'm going to keep using 12m, myself ... simply to keep everything as it has been. Over time, if other brewers widely accept that say ... "8 minutes" is the most accurate, I might switch for ease of communication. Right now though, I know what I'm getting with that 12m value.
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