First BIAB brew completed, some questions re water volume & scaling?

[SteveH]

Hi all!

Newbie here having just attempted (last night!) my first ever brew using BIAB in a 17litre stock pot on the kitchen hob.

Overall it went OK for a first attempt, but I got a little confused re the necessary volumes and ended up with a post-boil OG that was higher than planned.

I used https://www.themaltmiller.co.uk/product/robs-english-esb/ for ingredients, but due to the size of my equipment divided all the grain/hop/water quantities in half.

So the grain bill was:

2600g Maris Otter
113.5g Caramalt
60g Dark Crystal

The instructions said to mash in 2.5l/kg but since I was BIAB-ing I needed to mash with more water (I can only currently heat about 3l extra for sparging), so I mashed for 90mins at 67c with 11l of filtered tap water.

Then I squeezed the bag to get as much wort out as possible, and did a small rinse/dunk sparge (poured a pan of water over the grains, swished it round the bucket then drained/squeezed again) in the FV bucket with another 3l of 67c water.

This gave me about 14l in the kettle, which is exactly half the 28l suggested in the full recipe for pre-boil volume, so I went ahead and boiled for an hour adding hops (half quantity at the same schedule).

I forgot to take a pre-boil gravity reading (and there's no estimate in the recipe), but when I took a post-boil reading it was off the scale of my 1000-1060 Hydrometer - I estimate about 1065 and the recipe estimate was 1055. There was some trub in the sample jar but I'm pretty sure it wasn't obstructing the movement of the hydrometer.

Can anyone help me figure out where I went wrong, should I perhaps sparge more as I assume I've lost more than expected during the boil? Is there any way I can better estimate this next time?

Also wondering how this may affect the end result - I pitched just over half the packet of the supplied yeast and it's now fermenting OK by the look of the airlock, fingers crossed I guess! :)

 

[RichK]

I'm very new too. Today I did (just) my second kit free brew.

I'm not convinced you have 'gone wrong' - you've made wort that's now fermenting into beer. You may have had a better efficiency that the prediction. If you think you're getting a stronger beer than you want, then there's nothing stopping you adding water to the FV.

 

[simon12]

what was the volume that went into the fermenter?

 

[The Baron]

I think you have basically done it correct but you have boiled half the amount suggested but will have still roughly the same amount of boil off as if you had done the full quantity which will have concentrated your final amount hence the higher gravity reading me thinks.
just dilute the wort with boiled water to your required gravity if you do not want it to be too strong in alcohol. Brewers friend has a calculator for this but you would need the reading as it is now so a normal hydrometer is required with a larger scale - wilkos sell them

 

[SteveH]

what was the volume that went into the fermenter?

Ah, that leads to my second rookie error, neither the pot or plastic bucket have any markings so I don't have an accurate volume into the fermenter.

I just boiled, cooled then tipped the lot in (including most of the trub as I've not yet got a way to filter and it was past midnight by this point...).

Next time I'll use a different bucket or mark this one with volume on the outside, lesson learned!

I think you have basically done it correct but you have boiled half the amount suggested but will have still roughly the same amount of boil off as if you had done the full quantity which will have concentrated your final amount hence the higher gravity reading me thinks.

Thanks, this makes sense, I'd not considered that the boil off would be the same for the half batch.

I'm not too worried if it's stronger than planned for this batch, I just wanted to understand why so I can be more accurate next time :)

 

[The Baron]

no silly questions on this forum thats how most people learn but you are correct for a more consistent brew and to be able to understand where you have gone wrong and right you need to be able to quantify so a bucket with volume marks a hydrometer that will read above what you would normally brew also try brewers friend for recipe calculations may seem a bit daunting to start with but you will soon get the gist

 

[Portreath]

Sounds like you had a good brew day. The great thing about brewing is that you learn and improve at every attempt, and as @the baron said, their are no silly questions.