Best way to batch sparge?

[WelshPaul]

Hi folks, this should be a simple question but I'm just looking for a bit of clarification.

At present, I do not have the necessary equipment to do fly sparging so once the mash is complete and I've run the vorlauf off, I simply add enough water at 80-82°C to cover my grain bed by an inch or two, leave it for 10 minutes and then drain it off slowly at approximately 1l per minute.
I've never encountered problems in terms of low gravity but I was wondering if there is a better and more scientific way of doing this rather than simply adding the remaining water and hope that the total pre-boil volume and gravity at the end are correct! I've seen some advice of stopping the sparge once its gravity reaches a certain figure but would the pre-boil wort then need to be topped up with water to reach the desired volume?
Any advice would be welcome.

 

[PD]

I use the free beer soft wear called Brew Mate.
That tells me how much strike water to add initially for the mash of 60-90 mins whatever.
It also tells me how much wort I require to make my brew length of 19/23/25 litres whatever.
Subtract your strike water from that, and then halve the amount. I then use that amount for 2 batch sparges.......it gets me bye.

 

[pittsy]

i leave mine for 20 minutes and i also don't worry about speed of run off , but make sure your mash tun/grain doesn't get warmer than 75c , as the grains will have been somewhere like 68/72c they will retain almost all of that temp so adding water for batch sparge at 80+c is most likely to hot , you will find you only have to have your strike temp a little hotter say 76/78c but trial and error are the best way to find out as each set up is different (size and type of equipment) it is easy though once you've had a go.

 

[WelshPaul]

I assume that if the grains get too hot during the sparge they can release a variety of unwanted and unfermentable sugars?

 

[pittsy]

tannins nasty after taste with a dry sharp bitterish maybe even sour ish taste .... nasty done it myself , you don't want it in your beer

 

[PD]

Pittsy...would you recommend then not raising the temp of added water to 80c as suggested in soft wear, perhaps filling up with water at the mashing temp of 67-68C ??

 

[pittsy]

i would aim to get the grains between 72 and 75c and i have found using a ss thermo pot once first runnings is empty the grain is still around 65c ish (although i would of finished mashing around 72c ) and the last few times i've just gone for it and used water at around 78c and got my second batch sitting at around 73/75c . You want to raise the temp to 75c to stop enzyme activity , all the starch convertion should be complete before end of 1st batch and once you have raised a temp then lowering it won't revert back to a protein rest for example or whatever stage .