37 replies to this topic

[positiveContact]

so what does it mean when bicarb goes negative?

[neddles]

Im sure there is a technical reason however I never bother to look at that number. If the pH is correct and the flavor ions are where I want them the bicarb number is pretty meaningless to me in practical terms.

[matt6150]

Is there a situation where bicard is desired? I thought for stouts and really dark beers you actually wanted some bicarb?

[positiveContact]

Is there a situation where bicard is desired? I thought for stouts and really dark beers you actually wanted some bicarb?

 

in my water generally no.  if I do nothing to my water stouts are in the right pH range.  if I wanted to add gypsum or calcium chloride I'd have to add some baking soda to counter-act them to maintain my good pH.

[mabrungard]

A negative bicarbonate value doesn't really exist in reality. That negative value is essentially a placeholder that is used to tabulate the overall acidity and alkalinity of the various brewing components. Don't worry that the value is negative. It is often negative for paler colored beers. 

 

I'm not sure that I can characterize silicate harshness as anything more than 'harshness'.  If there are harsh tasting components in your beer, maybe this is a factor that you should being trying to avoid with your sparging procedures. While pH and temperature are widely reported to be factors in leaching tannins and creating harshness, I suggest that the most important factor is the gravity of your final runnings. Both tannin and silicate extraction rise rapidly as the wort gravity falls. I stop runoff at about 3 or 4 brix to avoid this problem. The popular recommendation is to stop at 2 brix, but I found that I still had a slight tannic edge in my beers. 

[positiveContact]

that seems unlikely to happen when batch sparging.  particularly for me since I mash as thin as possible (run out of space in my mash tun) such that my sparges are not very large compared to the total pre-boil volume.  I'm typically trying to collect 12 gallons and my sparge is rarely larger than 3 gallons.  Sometimes it's as small as 1.5 gallons.

 

tl/dr version:  the gravity of my batch sparge is very unlikely going to be very low.

[denny]

Martin, I've alwyas thiught of the gravity of the runnings as an indicator of rising pH. To me, the lowering of gravity of runnings reflects the loss of buffering cpability of the grain.

[positiveContact]

Martin, I've alwyas thiught of the gravity of the runnings as an indicator of rising pH. To me, the lowering of gravity of runnings reflects the loss of buffering cpability of the grain.

 

I thought that's what he was saying or am I reading one of you wrong?

 

lower gravity of the runnings = higher pH of the runnings.

[denny]

I thought that's what he was saying or am I reading one of you wrong?

 

lower gravity of the runnings = higher pH of the runnings.

 

I guess maybe that was what he was saying.

[positiveContact]

I guess maybe that was what he was saying.

 

hey, with that kitty constantly rolling you joints I'm surprised you can even type!

[Brauer]

While pH and temperature are widely reported to be factors in leaching tannins and creating harshness, I suggest that the most important factor is the gravity of your final runnings.  

It sounds like you are saying that low gravity has an effect independent of rising pH. Am I understanding that correctly?

[mabrungard]

If you are sparging with very low or no alkalinity water, it only takes a teeny bit of acid to drop the pH of the water to mash pH level or lower. Some brewers do that. However taking that thought forward, you wouldn't see a rise in pH as your wort diluted through the sparging process. So, I don't think you can equate pH and gravity very well. My findings and those reported in Malting and Brewing Science indicate that it is mostly the falling wort gravity that produces the conditions that enable tannin and silicate extraction.   

[denny]

hey, with that kitty constantly rolling you joints I'm surprised you can even type!

 

 

If you are sparging with very low or no alkalinity water, it only takes a teeny bit of acid to drop the pH of the water to mash pH level or lower. Some brewers do that. However taking that thought forward, you wouldn't see a rise in pH as your wort diluted through the sparging process. So, I don't think you can equate pH and gravity very well. My findings and those reported in Malting and Brewing Science indicate that it is mostly the falling wort gravity that produces the conditions that enable tannin and silicate extraction.   

 

In what way, Martin?  And if that's the case, it's another point for batch sparging!

[Brauer]

In what way, Martin? And if that's the case, it's another point for batch sparging!

And no-sparging!

[positiveContact]

And no-sparging!

 

or half way in between!

[Brauer]

or half way in between!

Half-sparging :|

[mabrungard]

 

In what way, Martin?  And if that's the case, it's another point for batch sparging!

For sure, batch and no sparge mashing make it virtually impossible to have problems with tannin or silicate. It's brewers like me that fly sparge that need to be aware of this problem. 

[positiveContact]

For sure, batch and no sparge mashing make it virtually impossible to have problems with tannin or silicate. It's brewers like me that fly sparge that need to be aware of this problem. 

 

*and ken with his high bicarb