Mild/bitter - Batch Sparge Only?

[Trent]

Gday all
Just coming into fly sparging, and had a few questions last one I did, that everyone helped me out with. It was mentioned more than once that you should be able to get around 6L wort per kg grain safely, without extracting tannins, which makes sense. I will be doing another ordinary bitter (1032 OG) soon-ish, and seeings as there is only about 3.5kg grain in there, and I will be requiring 30L preboil, does that mean that I wont be able to fly sparge, and only batch it, as I believe is the British way anyway? If fly sparging, that will be about 9L wort per kg of grain, and it sounds a little too much. Just wondering for future reference, really.
All the best
Trent

 

[vlbaby]

seeing your making such a low gravity beer, dont send all your sparge water thru the grain. Otherwise you will extract excessive tannins. Just sparge your grains as per your normal 6L wort/ kg grain rule , then top up the kettle with water to make your desired preboil volume.
You might want to plug in your figures to promash or the like to make sure you hit the right OG.

If you over sparge the grain with water too much , even batch sparging wont save your from astringency.


Cheers

vl.

 

[Trent]

Thanks for that vl
I batch sparged my last bitter, and it turned out fine, though I must admit, there is a slight hint of astingency I put down to the small amount of black malt I used. Maybe I should try your method on my next one, see how it goes. I figure that no matter what, if I get decent efficiency, and sparge to the 6L/kg, then I should hit my gravity, even if I have to add 10L of water to get to boil volume.
All the best
Trent

 

[Stuster]

I'd be very interested in the thoughts of other batch spargers on this 6L/kg wort to grain ratio. I certainly use more water than this and have not noticed any astringency.

 

[vlbaby]

stuster,
I must admit i hadn't heard of this 6L wort per kg thing, so I checked my brewing records to see what i had used on past brews. My last 15 AG brews ranged from 5.5L to 6.5L for each kg, so to me 6L/kg seems a fair rule of thumb if your not sure.
So maybe a fixed ratio isn't a bad thing.

cheers

vl.

 

[Stuster]

Not that I wasn't sure, that was just a point PoL made in another thread that I had never seen anywhere and I was wondering if anybody else had any experience with this. I batch sparge, with ratios more like 7-8 and have never tasted any astringency. Perhaps more a fly sparge issue. :unsure:

 

[goatherder]

The two OBs I made were at around 8L/kg, I didn't notice any astringency. I batched sparged.

Isn't the rule of thumb for fly sparging to sparge until the gravity hits 1.008, the point where astringency becomes a problem?

Applying the same principle to batch sparging, if the 2nd runnings have SG greater than 1.008, there shouldn't be any astringency problems. How does this logic sound?

Has anyone got any 2nd runnings readings from an astringent brew to confirm/debunk this theory?

 

[vlbaby]

The two OBs I made were at around 8L/kg, I didn't notice any astringency. I batched sparged.

Isn't the rule of thumb for fly sparging to sparge until the gravity hits 1.008, the point where astringency becomes a problem?

Applying the same principle to batch sparging, if the 2nd runnings have SG greater than 1.008, there shouldn't be any astringency problems. How does this logic sound?

Has anyone got any 2nd runnings readings from an astringent brew to confirm/debunk this theory?

That figure changes depending on who you believe. I've seen references that state 1.020 is the minimum SG that won't produce astringency. I have had astringency from a brew that had 2nd runnings of 1.025, but it could have been the hops. I can't be sure.



vl.

 

[Ross]

With fly sparging it's always a balancing act between extraction & astringency, as the top grains are flushed of all sugars quite early in the sparge. With batch sparging i've never known this to be an issue & my house amber is only 3%...

cheers Ross

 

[Trent]

This turned into a very interesting discussion
I have only ever made 2 low alc beers, one had quite a firm astringency, and my second one had a very slight taste of it, I batch sparged both times, and had around 9L water per kg grain, but could very well be hop astringency. Next time I will try fly sparging, and then do an equivalent brew batch sparging. Having a general rule of thumb L-kg seems like a pretty good idea to me though.
All the best
Trent

 

[Millet Man]

The two OBs I made were at around 8L/kg, I didn't notice any astringency. I batched sparged.

Isn't the rule of thumb for fly sparging to sparge until the gravity hits 1.008, the point where astringency becomes a problem?

Applying the same principle to batch sparging, if the 2nd runnings have SG greater than 1.008, there shouldn't be any astringency problems. How does this logic sound?

Has anyone got any 2nd runnings readings from an astringent brew to confirm/debunk this theory?

I used to get astringency when I first started mashing, would collect about 8 lt/kg, fly sparging and not adjusting pH of sparge water. Never recorded SG of last runnings back then.

Now I collect 5-6 lt/kg, fly sparging, sparge water pH is 5.7 and last runnings are around 1.006 to 1.008. No astringency any more.

In Brewing by Lewis and Young pp 213-218 there is some discussion on sparging, they state that 1.5P (1.006 SG) should be the final cut-off. Here's a quote that goes with the following diagram; "When gravity reaches about 5P, wort pH rises rather significantly (except with calcareous water, ----). Wort fermentability goes down and nitrogenous, fatty acid, mineral and tannic material increase dramatically per unit of recovered extract."



Cheers, Andrew.

 

[Peter Wadey]

Trent,
vlbaby's on the right track in terms of sparging. Aim to get the same efficiency from your system, then top up with water to target pre-boil.

Ross & others,
There won't be a dramatic increase in pH if you've already acidified your sparge water.

Rgds,
Peter

 

[Stuster]

In Brewing by Lewis and Young pp 213-218 there is some discussion on sparging, they state that 1.5P (1.006 SG) should be the final cut-off.

Thanks for the info Andrew. Just shows there should be absolutely no problem with batch sparging unless you use massive amounts of water, even without acidifying your water. 8L/kg should be fine.

Edit: On reflection, for batch sparging the aim is to have two equal volumes of water drained. The first half will have 58% of the extract, 42% in the second half. (See Mosher's writings on parti-gyle brewing.) So for the second runnings to be 1.006, the first runnings would be only 1.009 roughly, giving a pre-boil gravity of 1007 to 1008. To get such a low gravity, you'll need about 26L/kg, rather unlikely IMO. Another reason to batch sparge. h34r:

 

[JasonY]

Gday all
Just coming into fly sparging, and had a few questions last one I did, that everyone helped me out with. It was mentioned more than once that you should be able to get around 6L wort per kg grain safely, without extracting tannins, which makes sense. I will be doing another ordinary bitter (1032 OG) soon-ish, and seeings as there is only about 3.5kg grain in there, and I will be requiring 30L preboil, does that mean that I wont be able to fly sparge, and only batch it, as I believe is the British way anyway? If fly sparging, that will be about 9L wort per kg of grain, and it sounds a little too much. Just wondering for future reference, really.
All the best
Trent

Fly sparging should be fine. For a beer > 1.045 I just sparge to my required boil volume (27L) however with low grav beers like that I would keep an eye on the gravity of the runnings and stop when it hits 1.010 and top the kettle up with water as vlbaby says.