Help: Dr Smurto's Went Wrong

[mr_wibble]

Hi-yas,

This is my 3rd all-grain batch. I figured on making Dr Smurto's Golden Ale.

So I had my trusty HB shop mill the grain for me to a 24 litre batch recipe (was aiming for 20ish litres with a bit for the kitchen floor).
My recipe (generated out of BrewMate) said to mash 5.05 kg of grain with 12.6 litres, and then sparge with 19.7. (32.3L)

I started at 05:30 this morning, and everything went perfectly. Except I did have to rush out and buy some ice for the chill, so I ended up boiling for 70 minutes instead of 60. In a 30 litre pot too, FWIW.

But now I've put it into the fermenter, and (at a guess) there's probably only 16 litres wort in there. (WTF?!)

So I figured that perhaps I'd boiled it a bit to much, thus I checked the SG, and it's 13brix / 1.051 SG, which closely matches what the recipe says -> 1.049

I guessed I left a few litres in the pot along with all the hop slurry so I measured it -> 3 litres exactly.


But even including all the hop slurry leftovers, I'm down about 5 litres! Where did it go?

Any sage advice ?

-kt

 

[warra48]

You mashed with 12.6 litres, and sparged with 19.7 litres.
That's a total of only 32.3 litres, as you point out.
Allowing, say, 1 litre per kg retained by the grains, you will only start your boil with about 27 litres.

Don't know what your boil of % is, but for a 70 minute boil, you may well lose at least 15%, so you are now down to about 23 litres.
You left 3 litres in your kettle, so you are down to 20 litres.

Where did you lose an extra 4 litres? Among the possibilities are:
1. Maybe your boil was more vigorous than average, and you lost more to evaporation.
2. Your measurements are up the *** and not accurate.

I generally brew 25 litre batches, and I need to start with 35 litres pre-boil to make sure I end up with that volume. I think your will need to start with more than 27 litres at the start of the boil for a 24 litre batch. However, you seem to have only a 30 litre pot, so you will need to do a higher gravity boil, and then dilute to get your volume, or get a bigger pot!

I never take any notice of the volumes from brewing software. I know with my system to heat my strike water about 8C above my mash temperature. I just run the water in until I hit the right temperature, then stop. I do a mashout, only because I have only a 25 litre mashtun, and then drain. I measure what I've drained to the kettle, and the difference between what's there and what I need is the volume I need for my sparge. Too easy.

Will be interesting to see other responses.

 

[drsmurto]

The OG should be 1.047.

24L at 1.047 isn't too far off 16L at 1.051 allowing for some extra losses along the way.

Your mash and sparge volumes look fine so I'd suggest you may have just boiled more vigorously this time and got a higher boil off. Using a 30L pot for a post-boil volume of 24L sounds like some form of brewing houdini.

You can add a few litres of boiled, cooled water to up volume and dilute it back to the desired OG.

 

[Nick JD]

24L at 1.047 isn't too far off 16L at 1.051 allowing for some extra losses along the way.

A lot of extra losses. 16/24ths of 51 is 34.

1.034 is not 1.047.

 

[mr_wibble]

Using a 30L pot for a post-boil volume of 24L sounds like some form of brewing houdini.

I don't understand - so it shouldn't fit into my 30 litre pot ?

I mash with 12.6 litres of water, and get about 9 litres back
I sparge with 20 litres of water, get about 20 back

that fits into my pot with about 5cm to the top ... hmm, maybe my pot is a bit bigger, must check.

cheers,
-kt

 

[Brad Churchill]

I don't understand - so it shouldn't fit into my 30 litre pot ?

I mash with 12.6 litres of water, and get about 9 litres back
I sparge with 20 litres of water, get about 20 back

that fits into my pot with about 5cm to the top ... hmm, maybe my pot is a bit bigger, must check.

cheers,
-kt

What the Dr was getting at is that 24L in a 30L pot doesn't allow much room for boiling without having a boil over particularly as initially your problem seemed to be your boil is more vigorous than your volumes have allowed for.

Looking at what you have posted here though I would say that whatever you are using to measure your volumes may be out.
A 30 Litre pot would be roughly 31 cm x 31 cm meaning each cm equals almost exactly 1 litre.
So if you are putting 29 litres in it should be only about 1 cm from the top.

My guess would be that your pot is 30 Litres (but yeah check that also) and that when you are 5cm from the top you only have about 25 litres pre boil.
I get a similar boil off rate as Warra48 when making this volume using a 2.2kw heating element. So now you only have I think about 2 litres unaccounted for.
Now say you are 6 or 7 cm from the top of your pot pre boil which is probably likely as you haven't mentioned boil over issues then that is your other 2 litres accounted for.

Only your 3rd all grain you said so probably only your 3rd full volume boil yeah?

This is a good learning exercise then and I am sure if you check all these volumes you will find that yeah you were out a couple of litres here and a couple of litres there and they soon add up.

Measuring to the top of your pot pre boil and then post boil is a good way to check your boil off rate and provided you always use the same heating source and volume this shouldn't change much. You will also loose some volume as your brew cools.

Keeping very accurate records of all stages is the key to solving these kinds of issues and it enables you to hit your targets easily.

Good luck. Should still be a tasty brew.

Cheers
Brad