Small Batch Boil Time

[Paul Newton]

Hi forum

I am looking to brew a few smaller batches in my Grainfather. Got the micro pipe work sorted and whole heap of 20 litre recipe ideas from the GF forum which I guess should just be halved to make the 10l batches I want to play with. However what’s not clear to me is should there be adjustment to the mash, mash out, boil timings other than simply halving these as well. Any help gratefully appreciated

 

[Leon103]

Sorry confused. You half the ingredients and not the process.

 

[Paul Newton]

So same boil time etc...as for the larger batch then. That was my gut instinct however a home brew friend suggested the boil time should be less or it could lead to (eventually) a higher FG than the target. Cheers

 

[MagnusTS]

I think he might have meant that you may end up with relatively less volume due to different boil off rates with the smaller batch. Something to do with physics, and surface area, but I don't properly understand it.

You can always add more water after the boil to get your FG back down to your target if you boil too much off.

But I think quite a few people (myself included) do shorten boil times when doing small batches.
I just do half hour boils now, to shorten brew time, and haven't noticed any difference to the beer.

 

[Ben034]

Some people will do half hour boils and mashes even with 20+ litres. I prefer to mash and boil for an hour even with smaller volumes.

You could always boil 15l water (or whatever your expected pre boil volume will be) in the GF to see what the boil off rate is with a lower volume and then adjust mash /sparge water accordingly. Or top up after boil this time if needed, note boil off rate for next time and adjust water volumes for next time.

 

[Paul Newton]

Good tip!

Thanks a bunch

 

[Cwrw666]

If you're boiling in the same vessel as for a larger brew then the boil-off will be exactly the same - not in percentage, but actual volume lost. So yes that could affect OG assuming you haven't the nouse to just add back a bit of boiled water.