Batch Sparge Intensity

[locost]

I know if I were fly sparging I can sparge to a gravity of around 1.010 before I need to worry about extracting tannins.

Is there a similar rule of thumb for batch sparging? Just how heavily can I sparge in bathces?

 

[Aussie Claret]

locost,
In batch sparging because you never remove all the sugars, so you don't need to worry you can't remove tannins. You dont creat any channeling because during the sparge you are actually diluting the sugars and there will always be some present. You only start to extract tannins when all the sugars have been rainsed out of the grain.

When you sparge raise the temperature during mash out and final sparge, I use as close to boiling for final sparge stir and allow to sit for a few mintues then drain straight into the kettle.

AC

 

[warrenlw63]

Just going by my own setup On an average of 9kg grain I sparge around 55 litres into the boiler if that's of any help. I've never had any astringency or tannin problems.

Warren -

 

[locost]

locost,
In batch sparging because you never remove all the sugars, so you don't need to worry you can't remove tannins. You dont creat any channeling because during the sparge you are actually diluting the sugars and there will always be some present. You only start to extract tannins when all the sugars have been rainsed out of the grain.

When you sparge raise the temperature during mash out and final sparge, I use as close to boiling for final sparge stir and allow to sit for a few mintues then drain straight into the kettle.

AC

Sure, but when I'm batch sprging I am diluting the sugars. There has to be a point where if I run another gayle, I'll drop below the magic 1.010 figure and produce a very tannin laden run-off.

 

[Aussie Claret]

Nope,
During fly sparging the water enters the top of the mash tun, rinsing sugars from the grain at the tops of the grain bed or where channeling is evident, hence the possible removal of tannins.
In batch sparging because you are diluting the sugars and not removing all, you can't remove any tannins.

You could only remove tannins if you did several sparges to the point where you had removed all the sugars.
I may not be describing the process very well BUT you don't have any worries of extracting tannins with normal batch sparging techniques.
AC

 

[lou]

from what I understand - if the pH of your sparge water is below about 6 -5.5
you don't relly have to worry about extracting tannins - the problem with low gravity run off isn't low gravity per se - it merely indicates that if your sparge water is alkaline at low gravity readings you are likely to have raised the mash pH to the point where tannin extraction is likely.

If you adjust the pH of your sparge water you can sparge till the cows come home because you will never raise the pH of the mash and hence not be risking tannin extraction

lou