BIAB - first go NQR

[NigelP]

Hi All,

I have finished my first BIAB using a 30 Litre Crown urn and wasn't able to get anywhere near the volume expected into the fermenter and the gravity was way higher than expected.

I would appreciate any assistance I can get for my next go.

Before this BIAB attempt I have been modifying 1 Gallon receipes to give me enough to fill a 5 litre Demijohn.
My first 6 goes of this went really well, but the volume wasn't worth the effort hence the urn.

With these brews I used about 1.7kg of grain, 60 mash, 60 min boil and 9 Litre of water total that boiled down to give me 4.5 Litres in the Demijohn at an OG of around 1052.

I used my recipes and just doubled them hoping to get enough to fill my two Demijohn's from one session.

So the figures I used were:

3.5kg grain bill
9 Litres for the 60 minute Mash
9 Litres for the Sparge
60 Minute boil

I expected this to leave me with about 12 Litres at OG of 1052, of which 9 Litres would go into the fermenters.

What I got was barely 7 Litres of useable, clear(ish) wort.
Split evenly across the Demijohn's and then topped up with water I recorded an OG of 1062.

I assume I need less grains as the BIAB is getting more out of the grains than my previous method.

How do I work out the required amount of water I should use in order to get 9 Litres of clear wort into my fermenters?
I have since boiled the urn with just water as a test and on both ocassions recorded 3 Litre's of evaporation.

Thanks

 

[Stouter]

What's your method of sparging?
Aside from evaporation you'll have to allow for water that's taken into the grain and hops, trub and dead space below the tap.
Best to do a search for a calculator for this. I've got one from this site (Brewers friend), and another from else where which is a BIAB specific spreadsheet which deals solely with water.
Dial the software into your urn measurements and enter your grain bill size, etc, and they do the rest to give you starting water totals and such.

 

[Rocker1986]

Pretty much what Stouter said. Software will also help you work out your efficiency, a figure that will make it a lot easier to work out how much grain you need to use to hit your target OG in your target volume. I also BIAB in a Crown urn but I have the 40 litre size brewing either 21 or 25 litre batches, and I don't sparge so all the water goes in at the beginning of the brewing process.

I also no-chill my wort in plastic cubes. Over time I've worked out with my 75 minute boils that I need about 10 litres more than the intended batch size at the beginning of the boil, to get the targets in the fermenter. I boil off about 3L an hour as well (3.75L for the 75 mins), so that 6-7L extra allows for trub and other losses as well as the cube taking a couple of litres more than its nominated capacity.

I normally start with 11L more water than the intended batch size, but this is room temp water so even though it appears the grain is only soaking up 1 litre (ridiculously low), it's probably more like 2 litres due to the expansion in volume when the pre-boil wort is around mash temps. It's a pain the arse to try to explain, but after brewing with it for a few years I've worked out what volume markings the wort needs to line up with at those temperatures to achieve intended outcomes.

 

[wereprawn]

Changing your method probably gave you a more normal efficiency. 3.5 kg is a ****-load for 9 ltrs. As a comparison , to get 20 litres of 1052 out of my 30 ltr urn, I use around 4.2-4.3 kg of base malt (malt type dependent ), and my efficiency is within what most biabers consider normal . So you should really follow the above advice and use some brewing software to know exactly where you're at IMHO .

 

[Droopy Brew]

All the above is worth looking into. My bet is your evaporation was higher than expected so you got less volume and higher gravity.

 

[NigelP]

Thanks for all of the responses, I really appreciate the advice.

Stouter - I ended up having to mash with a bit more than 9 litres as it was really dry, probably 13 litres. I reckon the element cover I put in took up too much space for a small brew. After the mash I lifted the bag and placed it on top of the urn on a trivet and sparged with 5 litres of fresh 75 degree water from a jug straight onto the grain. I then poured about 5 litres from the urn and sparged it over too.

I have had a great play with Brewersfriend tonight and it is a fantastic resource.
I reckon I would have moved into AG brewing 10 years ago if I had of found it and this forum back then.
I used to do Coopers kits but got bored and AG seemed way too complex to start off so I gave it all up.

I have worked out I was getting about 55% efficiency with my Gallon brewing and I think I got around 70% with my BIAB.
I found a dilution calculator that suggests I had an OG of about 1.080 before I diluted down into the Demijohns.

If I have figured it out correctly, wereprawn are you getting 80% efficiency?

For my next brew I will brew the same recipe again but lower the grain bill to just under 3kgs and work on 10 litres of loss.
I have put some markings on the sight glass so I can watch the volume changes better. It is strange that they don't come with markings.

If I get the desired volume and my OG is too high again, I guess it means my efficiency it getting better.
It seems like a good problem to have as it means cheaper ingredients!

Thanks again

 

[wereprawn]

Yep. That's what I use in my software. 70's - low 80's seems like common biab efficiency from what i have seen. Good on you for having a go and refining your process. AG can seem a bit daunting with all the information overload new ag brewers often experience ( I know I did), but it's not really that difficult. Use the KISS principle when starting and it's hard to go too far wrong.

 

[ianh]

Another resource is my BIAB spreadsheet on this forum, I use a Crown 40 litre urn so not sure on 30 litre urn dimensions. Also I get 3.5 litres per hour boil off and run 80% efficiency, but I make mid strength beers so 70% is probably a got place to start, keep good records.

I don't use an element cover, you need to see if you can rig up a pulley system so you can raise the bag over the wort to the mash out, then get rid of the element cover.

Rather than putting markings on the sight glass use a steel rule to measure the depth and use a formula to calculate the volume or the spreadsheet, you have to make allowance for the element and bottom, weigh the water f you have to do this.

Any particular reason you are fermenting in Demijohns as you could probably brew say 15-18 litre brews in a 30 litre urn and ferment in a 20 litre bucket.

 

[NigelP]

Thanks for the info Ian, I will find your spreadsheet and refer to it too.

I thought the element cover was a bit of a waste but went along with the suggestion. As I am only brewing small amounts I can probably suspend the bag off the bottom tied to a piece of dowl resting on top of the urn for the mash out whilst I figure out how to install a pulley.

I am just using the Demi's as I was doing small brews in the kitchen up until now but they aren't really suitable as you say.
It seems they will soon end up in my very rapidly growing pile of stuff that is no longer suitable. At this rate my wife will be getting a nice handbag to even things out!

 

[Lionman]

Use some brewing software or Ian's spreadsheet.

These will tell you what your mash volume should be and what your pre-boil volume will be.

I try not to hurt myself with maths and let computers (and their programmers) do all the hard work.

 

[NigelP]

I had another go over the weekend and many of my processes improved from the advice given, but i still ended up a fair bit off.

I lowered my grain bill to 3kgs and worked on 10 litre of loss to evap and trub in brewersfriend to aim for 12 litres post boil
I mashed with the full 21 litres from the water calc and sparged about half of that back over.
Wrapping the urn in a camping blanket kept it right on 66 degrees the whole time.

I think this went great as my pre boil gravity was bang on 1036 and things looked great.

However I ended up 15 litres at OG 1044, when I was shooting for 12 litres at 1052.

In hindsight I should have dialed in 3 litres evap into the calc instead of the default of 6 litres.
I went back and edited the recipe with the observed 3 litre evap and it gave back an OG of 1044 at 72% efficiency, matching what I got.

So I think I am almost there. Next brew I will reduce the water volume by 3 litres and hopefully be knocking out at least same quality brew as before I moved to the urn. I have also bought a bigger fermentor, those demi's were still handy on brew day.

What difference other than abv should I expect from this beer due to the low than expected OG?
Will it be thinner than expected?

On a side note my wife just told me her friend is growing hops on her farm for fun and doesnt even brew!
Things are definately looking up.

Cheers

 

[Rocker1986]

Definitely some improvement there. The beer probably will be a little thinner, and may seem a bit more bitter from the higher BU:GU (bitterness units:gravity units) ratio due to the lower OG, but it'll still be beer and it's obviously been a learning experience too which is always useful.

 

[Lionman]

If you volume is high, boil for longer.

Just be careful of late hop editions, add them once you know your volume is going to be close to target.

 

[ianh]

Just look at it this way you will have about 25% more beer to drink.

 

[Ronix81]

Not to hijack NigelP's thread but I'm also about to give biab ago for the first time. I brewed k&k for years then moved into fwk but it's time to go AG. I was hoping to make something similar to one of the fwk I've used and will be using a 50litre keg with the top taken off and a big gas burner. Just wondering if someone could give me pointers on a recipe as such. As per the attached pictures it says it's 100%pilsner. Does that mean I would only use a pilsner grain? I've got beersmith so can work out amounts and volumes no worries but a little lost on where to start with grains to make something I know I like.

 

[wereprawn]

Not to hijack NigelP's thread but I'm also about to give biab ago for the first time. I brewed k&k for years then moved into fwk but it's time to go AG. I was hoping to make something similar to one of the fwk I've used and will be using a 50litre keg with the top taken off and a big gas burner. Just wondering if someone could give me pointers on a recipe as such. As per the attached pictures it says it's 100%pilsner. Does that mean I would only use a pilsner grain? I've got beersmith so can work out amounts and volumes no worries but a little lost on where to start with grains to make something I know I like.

ImageUploadedByAussie Home Brewer1495098713.468443.jpg

Yeah, 100% pilsner. You won't know your efficiency, so using a modest 70% would be a good starting point. When your maiden AG is done you will have a clearer picture of an appropriate efficiency to plug into your software. If your beer ends up a bit stronger /weaker on your first batch, you'll still have beer and will know how to proceed in the future.

 

[NigelP]

No worries Ronix, the guys around seem really helpful to everyone.

When I went to a brew session recently at Grain and Grape the guy running it suggested swapping out 5% of my grain bill for a wheat malt in an ale will help with head retention and mouthfeel. I have done that with the last two and I think it has made a positive difference.

I was planing to check in tonight as I have cracked the beer from the start of this thread with the higher than expected OG.

It has turned out to be very drinkable American IPA style at around 7%. I really like it.
I expected the hop flavour to be missing from the watering down I did, but the Citra hops have still come out really strong.
Perhaps I got lucky with the excess yeast I pitch as I expected it to be very sweet but the US-05 yeast munched away like a champ.

The one that with a lower than expected OG is about to be bottled this weekend and tastes pretty bitter and thin from the fermenter.

I am having a crack at an Oatmeal Stout this weekend with cold steeped dark grains, so hopefully I have everything dialled in now and hit my targets.

 

[Rocker1986]

Most of my batches taste more bitter out of the fermenter than they do once carbonated and ready to drink. Not sure why this is, but I wouldn't be overly concerned about it at this stage.