Batch sparging is the process which rinses the grains by adding
two lots of water in batches. The brew which was used on this occasion was the pilsner version of the lager on the all
grain recipe page. The recipe was changed to assume 72% effiency because of the lower yield which has affected home
brewers recently. Here is the revised recipe.
Pilsner Malt 3018g
Carapils Malt 432g
Flaked Maize 432g
Brewing Sugar 432g
All the other details of the recipe are unchanged, it is only the grains we are concerned about
here.
The first stage is to calculate how much water you will need for each stage, including the amount
of water which was used in the mash. Fortunately there is an excellent calculator available online on Jim's beer kit
forums in the calculators section. To find it, go to the links page on this website, click on the Jim's beer kit link,
then calculators.
Here is the calculation I used for this brew. I printed a copy of it to keep handy while
the brew was in progress
The calculator is easy to use. Enter your brew size in the required
box; in this case it was 23 litres.
Enter the percentage loss in the required box, in my case it is 15% as it was a 90 minute boil.
Had it been a 60 minute boil I would have entered 10%.
Enter your estimated loss in the required box. You will need to know this from your own system,
mine is 2 litres.
Enter the total grain bill in the required box. Mine came to 3.882g, the calculator rounded
this up to 3.9 as shown. If your brew contains sugar, please remember not to add this to the grain bill as the sugar
is not mashed.
Enter your mash tun dead space in the appropriate box. To determine this is simple. Connect
the strainer to your mash tun and put some water into it. I used around 10 litres myself.
I then drained the mash tun until the water stopped running from
the tap. There was a small amount of water remaining in the mash tun.
I then poured the remaining water in the mash tun into a jug and
measured it.
The amount collected in the jug was a quarter of a litre; this
is the amount that I need to enter in the appropriate box. I entered 0.25; the calculator changed it to 0.2.
Enter the mash water to grain ratio in
the appropriate box. I used 2.5 litres of water for each kg of grain; therefore I entered 2.5 in the box.
Then press the calculate button and you will
have your water amounts calculated for you. Now I have this information it's time to start sparging.
Please go to the next page, batch sparging.
