My 1st Ag

[Guest Lurker]

When you recirc, you might find it better to have the tube on the tun outlet, and use 2 jugs. Then you arent splashing the runnings as much which isnt likely to be a problem but might as well avoid it if you can. And you can have a continuous outflow, instead of turning the tap off after each jug, and turning the tap off to put the tube on, which I find helps to clear the runnings faster.

 

[raven19]

Nice early start for that first brew! Well done!

Welcome to the world of AG Brewing.

(If its any concilation, I have left out false bottoms in the esky before...!) :icon_cheers:

 

[Greg Lawrence]

2nd brew I was aiming for 19L @ 1.057.
Got 14L @ 1.065.
Dont really know where I am going wrong.
Might have to do the next one sober.

 

[Screwtop]

2nd brew I was aiming for 19L @ 1.057.
Got 14L @ 1.065.
Dont really know where I am going wrong.
Might have to do the next one sober.

Add 2L of boiled water and your grav will be spot on , vol 16L.

What volume did you have preboil?

Screwy

 

[schooey]

Calculated evaporation at 10% per hour (90 min boil) so about 3.75l evap.

I'd say this is where you are going wrong... The old using the percentage instead of the actual l/min boil off rate of your kettle and burner combination... It looks like you are using a Toohey's type keggle, I find with my Rambo burner at a moderate boil rate, I'm losing close to 5.5 l/min, so on a 90 min boil, thats close to 8 litres..

Maybe do a test run with water for an hour and see how many actual litres you lose, not %, then adjust the percentage in your brewing software of choice to reflect that number, dependant on batch size

 

[Greg Lawrence]

Add 2L of boiled water and your grav will be spot on , vol 16L.

What volume did you have preboil?

Screwy

Not too sure of the preboil volume as I havent worked out an accurate deadspace in the mash tun. Also need to do some measurements in the keg to work out aprox volumes.

Now to really throw a spanner in the works I have just taken some SG readings of a couple of brews in the fermenters (partials) and got completly different readings with my hydrometer and my refractometer.
I was using my (new) refractometer for the readings during the AG brews.
When testing my brews in fermenters I got 1.014 with the hydro, but 1.030 with the refract.
Sample was at 20deg (out of fermenting fridge).
Which one do I trust?
Refract was calibrated to 0 with boiled water.

 

[Greg Lawrence]

I'd say this is where you are going wrong... The old using the percentage instead of the actual l/min boil off rate of your kettle and burner combination... It looks like you are using a Toohey's type keggle, I find with my Rambo burner at a moderate boil rate, I'm losing close to 5.5 l/min, so on a 90 min boil, thats close to 8 litres..

Maybe do a test run with water for an hour and see how many actual litres you lose, not %, then adjust the percentage in your brewing software of choice to reflect that number, dependant on batch size

Good idea schooey. Ill do some evap testing at the same time I will put some litre markings on the kettle.
I dont think a few scratch marks are going to harbour bacteria on the inside of the keg.

 

[eric8]

Good idea schooey. Ill do some evap testing at the same time I will put some litre markings on the kettle.
I dont think a few scratch marks are going to harbour bacteria on the inside of the keg.

Have you still got the dip tube? If you do, you could use that as your gage and cut some marks into that rather than the keggle.

 

[np1962]

Not too sure of the preboil volume as I havent worked out an accurate deadspace in the mash tun. Also need to do some measurements in the keg to work out aprox volumes.

Now to really throw a spanner in the works I have just taken some SG readings of a couple of brews in the fermenters (partials) and got completly different readings with my hydrometer and my refractometer.
I was using my (new) refractometer for the readings during the AG brews.
When testing my brews in fermenters I got 1.014 with the hydro, but 1.030 with the refract.
Sample was at 20deg (out of fermenting fridge).
Which one do I trust?
Refract was calibrated to 0 with boiled water.

With fermenting beer you can't just use the refrac reading as is. You will need to do an adjustment.
The formula is on here somewhere, you may need to do a search.
If you have beersmith I think that has an adjustment tool.

Cheers
Nige

 

[Greg Lawrence]

With fermenting beer you can't just use the refrac reading as is. You will need to do an adjustment.
The formula is on here somewhere, you may need to do a search.
If you have beersmith I think that has an adjustment tool.

Cheers
Nige

Thanks for that Nige.
That would explain alot.

 

[crozdog]

Congrats on the 1st AG. Well done.

To work out your tun dead space, pour a few litres of water in then drain. measure whatever is left - that's your dead space enter it into your software.

You can mark up a diptube or scribe the kettle or use this method:
- measure the internal diameter of the keggle in centimetres.
- Using pi r^2 calculate the volume (ml) per cm.
- Wack this into a spreadsheet, print it out you have a handy lookup table.

All you need now is a cheap steel rule to measure the depth - refer to the sheet & there is your volume.

Note this may not be accurate if the keggle has a dished base...... but it does work on any flat bottom kettles ;-)

 

[Jazzafish]

Doing well Greg!

congrats mate and can't wait to taste them/brew along side. we are due for another group brew in the club

 

[Greg Lawrence]

Doing well Greg!

congrats mate and can't wait to taste them/brew along side. we are due for another group brew in the club

A group brew sounds like a good idea. I would probably learn alot from it.
Bring it on.