Author Topic: RA over SRM simulation  (Read 5003 times)

Offline bluesman

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Re: RA over SRM simulation
« Reply #30 on: December 04, 2009, 07:42:24 AM »
So the thinner the mash the better the conversion due to lower pH... right?
Ron Price

Offline Kaiser

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Re: RA over SRM simulation
« Reply #31 on: December 04, 2009, 07:50:00 AM »
So the thinner the mash the better the conversion due to lower pH... right?

No, I wouldn't say that. The thinner the mash the better the conversion because of faster gelatinization and less enzyme inhibition. There will be a point where mashes are too thin. This point, however, is likely beyond 3 qt/lb and therefore unlikely to be encountered in brewing.

Kai

Offline ndcube

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Re: RA over SRM simulation
« Reply #32 on: December 04, 2009, 07:51:15 AM »
I think what he's saying is that the thinner mash just amplifies the effect of the water profile on the pH.  If the RA is high you may end up with a higher pH.


Edit: Sorry, I didn't see the above post when I wrote this.

Offline a10t2

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Re: RA over SRM simulation
« Reply #33 on: December 04, 2009, 07:59:11 AM »
If you look at this picture
http://i154.photobucket.com/albums/s268/lostshaker_photos/Forums/SuggestedSRMColorGuide.jpg
you can see how John's nomograph falls apart for our water. Well, in truth, you may not readily see it. The proof is in the pudding. Based upon a water report and the RA methodology it would say our beers should be 18-22 SRM.

Sorry but you're using the nomograph incorrectly. Once you determine your RA you draw a line vertically from that point through the color band. Your RA corresponds to a beer color of about 6-10 SRM.
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Offline ndcube

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Re: RA over SRM simulation
« Reply #34 on: December 04, 2009, 09:30:37 AM »
Kai,

In your experiments was your roasted grain crushed or pulverized?  You may have answered this somewhere else but I don't recall the answer.

Thanks.

Offline Kaiser

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Re: RA over SRM simulation
« Reply #35 on: December 04, 2009, 11:35:23 AM »
In your experiments was your roasted grain crushed or pulverized?  You may have answered this somewhere else but I don't recall the answer.

All the grains were pulverized. I know that that can be a source of error, but as long as my prediction are close enough to my actual mash pH values do I not want to worry anout that. I just hate to have to account for crush since it is diffucult to predict it's impact. What if not onlt the gap spacing but also the mill design matters.

Kai

Offline bluesman

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Re: RA over SRM simulation
« Reply #36 on: December 04, 2009, 12:43:58 PM »
So the thinner the mash the better the conversion due to lower pH... right?

No, I wouldn't say that. The thinner the mash the better the conversion because of faster gelatinization and less enzyme inhibition. There will be a point where mashes are too thin. This point, however, is likely beyond 3 qt/lb and therefore unlikely to be encountered in brewing.

Kai

In that a thinner mash enables better conversion, would you suggest there is an ideal local environment in and around the crushed grains for conversion to take place...in other words there is less sugar saturation per unit volume in the localized areas because there is more volume of liquid.
Ron Price

Offline Kaiser

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Re: RA over SRM simulation
« Reply #37 on: December 04, 2009, 12:53:48 PM »
In that a thinner mash enables better conversion, would you suggest there is an ideal local environment in and around the crushed grains for conversion to take place...in other words there is less sugar saturation per unit volume in the localized areas because there is more volume of liquid.

Yes that's my understanding why thinner mashes seem to convert more easily. I also fond data that suggests that the gelatinization temperature of starch raises as the sugar concentration increases.

Kai

Offline MDixon

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Re: RA over SRM simulation
« Reply #38 on: December 04, 2009, 04:08:11 PM »
Sorry but you're using the nomograph incorrectly. Once you determine your RA you draw a line vertically from that point through the color band. Your RA corresponds to a beer color of about 6-10 SRM.

Don't be sorry  ;)

Good point. I didn't make the diagram and so it never dawned on me what you just pointed out. The problem is our water easily makes 2 SRM brews so the RA still falls apart, but not as dramatically as I had been led to believe.

Someone asked what our water profile was. That is a good question. The last time I used any data was 2-3 years ago and another member provided the info. I thought someone posted some recent results, lemme see what I can dig up.

Here's some data:
http://www.raleighnc.gov/portal/server.pt?space=Dir&spaceID=1&in_hi_userid=2&control=OpenSubFolder&subfolderID=4840&DirMode=1#

For the city water (most of us) it looks like for 2009 avg:
pH = 8.4
Total Alkalinity, mg/l as CaCO3 = 30.4
Total Hardness, mg/l as CaCO3 = 28
Iron, mg/l = 0.03
Manganese, mg/l = 0.01
Chloride, mg/l = 12.4
Nitrate, mg/l as N = 0.10
Ammonia, mg/l as N = 0.39

Here is a well sample from our area:
Na = 20
K = 2
Ca = 28
Mg = 3
Total Hardness, CaCO3 = 83
Nitrate = 0.8
Sulfate = 3
Chloride = 6
Carbonate = <1
Bicarbonate = 101
Total Alkalinity, CaCO3 = 83
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Offline Kaiser

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Re: RA over SRM simulation
« Reply #39 on: December 04, 2009, 04:12:43 PM »
Your residual alkalinity is just ~60 ppm which is still ok for light beers. Do you have a mash pH reading for an all pilsner malt mash?

Kai

Offline bo_gator

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Re: RA over SRM simulation
« Reply #40 on: December 06, 2009, 07:22:56 AM »
Your residual alkalinity is just ~60 ppm which is still ok for light beers. Do you have a mash pH reading for an all pilsner malt mash?

Kai

Funny you should ask. Over here on this end of the sate my ater profile is:

pH 7.4
Total Dissolved Solids (TDS) Est 39
Electrical Conductivity, mmho/cm 0.07
Cations / Anions, me/L 0.6 / 0.5
ppm
Sodium, Na 8
Potassium, K < 1
Calcium, Ca 4
Magnesium, Mg < 1
Total Hardness, CaCO3 14
Nitrate, NO3-N < 0.1 (SAFE)
Sulfate, SO4-S 4
Chloride, Cl 2
Carbonate, CO3 < 1
Bicarbonate, HCO3 15
Total Alkalinity, CaCO3 12

This past Friday 912/4/09) I brewed an all base malt Saison. I added 6g of Calcium Chloride to boot my pathetic Ca levels. The resulting profile was:
Water Profile:
Ca-90,
Mg-0,
Alkalinity as CaCo3-12,
Na-8,
Cl-155,
So4-4
RA as CaCO3--53,
effective hardness-65...

With this water I mashed:

10.5 lbs of MFB Pilsner malt (1.7 SRM)
1.125lb of Best Malz wheat (2.0 SRM)

My water ratio was 1.72:1

On my cheap PH meter that I had calibrated twice that morning I got a mash PH of 5.8-5.9 ( the meter was back and forth between the two)

After reaching my boil volume I got a PH of 6.2 and OG of 1.016 with the mash-tun leftovers.

These have been my highest PH numbers I have ever measured.   
All views expressed in the above post are those of the author and do not necessarily represent the views of any other member of the AHA, BJCP, or home brew community at large.   


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Offline MDixon

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Re: RA over SRM simulation
« Reply #41 on: December 06, 2009, 10:52:48 AM »
Your residual alkalinity is just ~60 ppm which is still ok for light beers. Do you have a mash pH reading for an all pilsner malt mash?

I'll assume this was headed my way. The answer is no. I have never performed an all Pilsner malt. I did perform an all pale malt a couple of times back in the day (read as 8+ years ago) and the pH was 5.4 IIRC (might be able to find the post somewhere in the RCB archives, but it didn't pop up this morning). Ever since then I've never worried about the pH of the mash since it fell into line with a 100% pale malt grist. I've known others in our club who check it every time, but never adjust, so I figure why bother.  ;)
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Offline ndcube

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Re: RA over SRM simulation
« Reply #42 on: December 07, 2009, 07:05:17 AM »
Here is some data from my mash yesterday.

22qts of water (RA = -31)
10lbs of TF MO
pH after 20 min was 5.3.

After the 20 min reading I added 4oz roasted barley.
I checked again at the end of the mash and the pH dropped closer to 5.2.

I was using colorpHast strips.

Just thought I'd share.

Offline Kaiser

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Re: RA over SRM simulation
« Reply #43 on: December 07, 2009, 07:15:45 AM »
I was using colorpHast strips.

Did you correct for the 0.3 pH unit error that these strips have? If not your numbers look like what I would have expected.

Kai

Offline ndcube

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Re: RA over SRM simulation
« Reply #44 on: December 07, 2009, 07:24:15 AM »
I was using colorpHast strips.

Did you correct for the 0.3 pH unit error that these strips have? If not your numbers look like what I would have expected.

Kai

It appeared to read 5.0 and then slightly less than that.  I added .3.

I started with 5.5 gal of distilled water and added 3g Calcium Chloride & 1g Epsom Salt.