Boil amounts...

[SuperBroo]

Hi All,

Can you please tell me if this is correct for an AG brew...

In a perfect brew setup, you would mash the grain, and the total of your first and second runnings would be the correct pre-boil amount, including the amount of evaporation lost during the boil.

Then at the end of the boil, you would have the correct amount for your fermenter.

I know its not that easy, but is that what we are chasing with efficiency / water volumes etc, or are we supposed to be aiming at a specific pre-boil gravity, more than a preset volume ?

Also, what is the simple explanation, of how I measure my mash efficiency ?

Sorry if this is a wierd question, its just that I dunno if I'm supposed to strive for the correct pre-boil volume, or a correct pre-boil; gravity, but please dont bl00dy tell me its both

cheers,
Chris...

[drsmurto]

Beersmith does all the calculations for you. I assume you are using a program like that?

You can set your efficiency and then after the beer has been brewed type in the real numbers rather than the predicted to get your actual efficiency.

You need to measure both SG and volume pre and post boil.

Hitting your pre-boil volume/SG lets you know you are getting the right efficiency out of your mash.

The final SG and volume will help you tweak the boil off % so you hit your desired targets.

As for how to measure your mash efficiency, I don't bother with the calculations as beersmith does all this for me. There is a section in Palmer's 'How to brew' that discusses this if you are interested

[SuperBroo]

cheers for the reply Doc,

yes, using beersmith, but it takes a few brews i think to get used to it / get it dialled into my setup.

i'll be watching all the numbers real closely, and recording it all properly on my next brew, been a bit slack
(and been told off here because of it)

cheers,
Chris

[warra48]

I also use Beersmith, and let it do all my efficiency calculations for me.

Once you have done a few brews, you should be able to get reasonable consistency in mash efficiency, within a range of about 5% or so. It's not really critical to get any closer than that, as far as I am concerned.

As to volumes, again, you need to do a few brews to establish what the output of your system is.
I no longer bother with the predictions or recommendations by Beersmith. I simply heat my HLT to about 7ºC above my desired mash temperature. I underlet about 6 or 7 litres of water, dump in my grain, and stir vigourously while slowly adding more water. As I do this I measure the temperature of the mash, and when I get within 1 or 2ºC, I stop adding water and allow the temperature to settle. I can add more hot or cold water to fine tune the last º or so.

Once I've done my first run off, I measure what I have in my kettle. For my system I need about 31.5 litres pre-boil for a 23 litre batch. Assuming I have drained 16 litres, I know I need to add 15½ litres to the mashtun for my sparge to give me my total volume. Simple.

If you find you have boiled off too much, you can always add some more water during the final stages of the boil. If you have boiled off too little, either boil more vigourously , or reduce your pre-boil volume next time.

I only do two hydro readings before I pitch my yeast. The first is when I have my desired volume in the kettle. I measure the SG and temperature, adjust it, and enter it into BeerSmith to give me my mash efficiency. The second is when I have drained into the fermenter to get my OG, again temperature adjusting.

Once you've done this a few times, it really is quite easy.

[SuperBroo]

Thankyou warra, I have printed that out and will stick that on my fridge, thats exactly the info i was after.

cheers,
Chris