Biab - Maximum Grain Bill For A 40l Urn?

[Newbee(r)]

I have been starting to brew some higher gravity beers recently, (7% +) using biab, and was keen to know if I reduce the water volume (usually 34L starting, resulting in 22L at 6% with trub remaining in the urn) and instead go for 15-18L final volume can I increase the grain bill to hit the desired abv with grain alone?

The maths seem to work but wondered in practice if there was too much grain to water for the method and efficiency would diminish as the level of grain to water increased.

At the moment, I am putting up to 5.5kg of grain for the 6-6.2% abv or so for the volume, and making up the difference for the target abv with LDME or can of extract for my scotch ales. These are coming out very tasty and to style, no hot alcohols etc but wonder if they could be even better still if they were all grain?

Keen to try some of the 8-9% plus beers to put down for winter (eyeing off a pliny) and also interested to see the difference between a complete grain and a grain/extract beer at this alcohol level, but don't particularly want to waste a batch worth of grain if people have tried and learnt better of it.

"every grain is sacred, every grain is good... if a grain is wasted.."

If there is little gain in flavour given the current 5+kg of grain already, I figured I will stick with current way of doing things and go for volume...

Thanks in advance

J

 

[Mr. No-Tip]

I am sure those with more expertise will weigh in, but I thought I'd give you an experience I had by accident.

Brewing a SMASH Blonde Ale with 4.5kg of pale ale malt in my 30l urn, I meant to have 19l go into my cube but it was more like 17l. I hadn't done any research into the impact of watering down pre ferm at that point, so I decided to go with it as is. Was expecting about 5.2 ABV, but post ferm, I calculated an ABV of about 7.2-7.5% (depending on if I trust my hydro or refractometer).

In the meantime I did some reading on watering down pre and post ferm - I would definitely water down pre-ferm next time, but I did water down some post ferm this time...it's still quite drinkable and more appropriate for style. I kept a few as 'Imperial Blondes', but haven't tried them yet....

I don't really have enough experience to suggest I could do this on purpose, but it seems it can be done!

 

[stux]

With 11.6KG and 32L or so of Strike you should be able to get 22L End of Boil with 1.090 for 20L into fermenter with a 90 minute boil but that's a woeful efficiency. 52% or so. Any more grain and you will actually end up with a lower gravity due to dropping efficiency!


Alternatively if you sparged with 10L you would only need 8.7KG and 25L of strike, and then you would have 71% efficiency into fermenter.

The same 11.6KG of grain with with 27.5L strike and 10L sparge would then get you 20L of 1.110 into fermenter.

If you didn't want to sparge, and you wanted to do 1.110, then you could aim for 16L into fermenter. You would still use 11.6KG of grain, 32L of strike and no sparge. Final result, 52% efficiency into fermenter again.

Assuming 5.83L/hr evaporation and 90 minute boils.

View attachment CE_BIABcalc_2012_02_24_2.xlsm.zip

 

[Phoney]

The biggest grain bill I have tried so far has been 9.2kg.

What you need to do is fill your urn with the desired strike volume, eg: 33L.

1. Then drain 10L - 15L into a stock pot.
2. Mash in as per usual.
3. As you raise the temp to mashout temps, put the stock pot on your stove and raise that to your mashout temp also.
4. Lift the bag out and drop into a clean bucket
5. Turn the urn on to boil and while you are waiting for it to boil....
6. Pour stock pot water into the bucket and give the grain a good mixing through.
7. Lift the bag out of the bucket and squeeze/drain. Get all those sugaz outta there!
8. Tip the bucket contents into the urn for boil.

Doing this should achieve your desired gravity / efficiency without spilling precious wort onto the ground. I should imagine that the process should work for any beer up to a barley wine if want to give it a go and kindly report back the results!

 

[Brewman_]

Newbee®,
Here's what I do, which is a little different from what your doing but might help with higher gravities.

I have a 47L kettle and my brew method is BIAB. Without checking exactly the numbers here's what I normally do. The main thing is to work backwards from what you want to get out. My aim is to achieve 2 corny kegs of between 4 to 7% alc, depending on the style of the beer. I no chill, so that means I knock out 2 x 15L cubes, (In reality that is actually 2 x 17L). So I brew to a higher gravity to allow the dillution of the cube into the fermenter to make it up to say 21L, just enough for 1 Corny per cube.

Mash in up to 11Kg, probably could do more, of grain in say 34L. Seems to fit OK. Mash and then pull bag. I found that with the higher gravity you really have to sparge or otherwise you will get poor efficiency. The volume of sparge water needs to be calculated carefully to allow the sparge to work well and to provide the right volume that does not exceed your kettle and does not overly dilute your boil. Need to consider, kettle loss, boil loss, and what you final knock out volume is.

So I sparge with 18L of waterat 7 8Deg.C . This provides the remaining total water required for the brew. This works for me, and then I just monitor the knock out volume at the end of the boil and the SG using a refractometer.

Efficiency should be at least 75 to 80%.

Hope this helps

Fear_n_loath

 

[Fat Bastard]

Newbee,
Here's what I do, which is a little different from what your doing but might help with higher gravities.

I have a 47L kettle and my brew method is BIAB. Without checking exactly the numbers here's what I normally do. The main thing is to work backwards from what you want to get out. My aim is to achieve 2 corny kegs of between 4 to 7% alc, depending on the style of the beer. I no chill, so that means I knock out 2 x 15L cubes, (In reality that is actually 2 x 17L). So I brew to a higher gravity to allow the dillution of the cube into the fermenter to make it up to say 21L, just enough for 1 Corny per cube.

Mash in up to 11Kg, probably could do more, of grain in say 34L. Seems to fit OK. Mash and then pull bag. I found that with the higher gravity you really have to sparge or otherwise you will get poor efficiency. The volume of sparge water needs to be calculated carefully to allow the sparge to work well and to provide the right volume that does not exceed your kettle and does not overly dilute your boil. Need to consider, kettle loss, boil loss, and what you final knock out volume is.

So I sparge with 18L of waterat 7 8Deg.C . This provides the remaining total water required for the brew. This works for me, and then I just monitor the knock out volume at the end of the boil and the SG using a refractometer.

Efficiency should be at least 75 to 80%.

Hope this helps

Fear_n_loath

I follow a very similar process, except I use a 36 litre ketttle and drain the bag and kettle directly into a 25l bucket and sparge through the bag with hot water, then run it back to the kettle to get the pre boil volume. Depending on the grain bill I regularly hit 75-80% efficiency for 1.075 sg and higher.

 

[Brewman_]

I follow a very similar process, except I use a 36 litre ketttle and drain the bag and kettle directly into a 25l bucket and sparge through the bag with hot water, then run it back to the kettle to get the pre boil volume. Depending on the grain bill I regularly hit 75-80% efficiency for 1.075 sg and higher.

Cool.

So what grain mass do you use in you 36L Kettle? And what is you knock out volume and what type of cube do you use? And what is your aim at the end of the process in terms of bottles / kegs with your 36L Kit?

Fear_n_loath

 

[Fat Bastard]

Cool.

So what grain mass do you use in you 36L Kettle? And what is you knock out volume and what type of cube do you use? And what is your aim at the end of the process in terms of bottles / kegs with your 36L Kit?

Fear_n_loath

I'm happy if I can get 20 or 21 litres into the primary, and fill 20 to 24 longnecks at the end. I factor in losing 6 litres or so to the plate chiller and trub, although that's only been for the last few brews I've done since using brewbrite, I prefer to leave as much of the hot break and presumably PVPP in the kettle as I can. I'm trialling an Aldi urn on the next brew to provide a lesser volume (6.25l of boiling water vs 10l of 65 degree) of hotter sparge water so will probably have to recalculate again.

I use a bag with a voille bottom and cotton duck sides so the sparge water travels through the grain rather than around it, which probably adds something to efficiency too, and I'm planning to add a pump to recirculate to aid stepped mashes at some point in the future.

Edit: I've used up to 8kg grain bills with this set up. The mash is pretty thick at this point, although I think I could probably go even more if needs be. We'l see how it goes with the hotter sparge.

 

[Newbee(r)]

Thanks to all for replies, looks like there are a few ways around it to avoid the LDME. Pliny the Elder clone now firmly on the agenda.

Cheers

J

 

[Brewer_010]

@Fear_n_loath
this method looks really good, I'm going to start double batches in my urn as I am finding it hard to get 4-5 hours time for just one brew - even contemplated ditching brewing altogether and either going fwk's or buying it...
Have you had any problems with infections in your second cube or do you just ferment both at the same time?

 

[Brewman_]

@Fear_n_loath
this method looks really good, I'm going to start double batches in my urn as I am finding it hard to get 4-5 hours time for just one brew - even contemplated ditching brewing altogether and either going fwk's or buying it...
Have you had any problems with infections in your second cube or do you just ferment both at the same time?

Brewer_010
Hey I went to double batches for the same reason, make the most of the brew day with the gear I have. And I did not want to spend any money at the time or right now, although I know there are better ways to brew with different gear, so this aint the best process going. But I am happy with it at the moment.

I used to brew single batches into a 25L Cube and more recently into two 15L cubes - all no chill, I have never had an infection out of a no chill, and yes I have had some infections. But that really is a separate issue to the brewing process I mentioned, as no chill requires all the right sanitation and good process to work well regardless of brew process. I have stored no chill cubes for over 3 months. So I fermented a cube for Bitter and Twisted last November, and just recently fermented the second cube, and tastes just the same.

Normally I try to brew both Cubes at the same time, but for some reason or another, it does not always happen but is the plan, except lagers that I just can't fit 2 in the fridge.

I had a lot of help from MHB to work out things like mass of grain, strike water volume, sparge water and the total amount of water required where and when to make it work. But it is a reverse calculation from the output you want.


Hope this helps.

Fear_n_loath

 

[Phoney]

I'm going to start double batches in my urn as I am finding it hard to get 4-5 hours time for just one brew - even contemplated ditching brewing altogether and either going fwk's or buying it...

I ditched brewing on weekends for this reason. Now I prepare my brew water the day before, set the thermostat on the urn at 70C, set a timer to turn on at 4pm, and it's all ready to dough in as soon as I get home from work the next day at 6. I'm all cleaned up, done and dusted by 10:30- 11pm that night. Beats watching telly.