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mikel
Member
Username: Mikel
Post Number: 227
Registered: 02-2001
Posted From: 4.246.215.124
| | Posted on Friday, April 24, 2009 - 08:28 pm: | 
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Question on the spreadsheet regarding the number to enter in the field "weight of acid" and "percentage". What would I enter if using 10% phosphoric acid? |
Tom Meier
Advanced Member
Username: Brewdawg96
Post Number: 898
Registered: 03-2003
Posted From: 75.76.167.200
| | Posted on Friday, April 24, 2009 - 10:31 pm: |
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Its very similar to SG calcs in brewing. 85% acid has SG=1.445. To convert to 10% acid:
points = (445/85)*10 = 52
so SG=1.052, or density=1052 mg/ml
I hope that is right anyway. Is the 10% you are quoting in %w/w?
Palmer's sheet may more built in than my old one does, he has expanded on things alot. |
mikel
Member
Username: Mikel
Post Number: 228
Registered: 02-2001
Posted From: 4.246.208.248
| | Posted on Saturday, April 25, 2009 - 04:26 am: |
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Thanks Tom-
A few questions. So when I enter the number 1052 in the mg/ml field and 10 in the % field why does the amount of acid needed change when I input different acid names in the acid type field?
The phos acid I have is from B3. It is labeled at 10%.
Lastly, can I use hydrochloric acid from the hardware store(muriatic acid)? It is labeled at 32%. Do I do the same calculation for this, as in, (140/25)X32?
Thanks! |
Tom Meier
Advanced Member
Username: Brewdawg96
Post Number: 899
Registered: 03-2003
Posted From: 75.76.167.200
| | Posted on Sunday, April 26, 2009 - 12:16 pm: |
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I would only use USP grade acids meant for human consumption. That looks right for the HCL conversion though.
You have to know how many hydronium ions the acid gives up. This is a complicated calculation that takes into account several things. First the molecular weight, volume, and concentration of the acid are used to figure out how many moles of the acid you are putting into the water.. Literally, this is a way of accounting for how many molecules of acid are added. So for different molecular weight acids, this number changes even though the volumes and concentrations may be the same.
Then, there is a complicated formula that accounts for the pk of each particular acid. This has to do with how easily the acid solution gives up its hydronium ions (H+), or more literally how strong the acid is. HCl is a very strong acid, but only gives up one H+. Other acids give up more than one, but only at certain pH values. |
mikel
Member
Username: Mikel
Post Number: 229
Registered: 02-2001
Posted From: 4.246.213.169
| | Posted on Sunday, April 26, 2009 - 02:55 pm: |
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Thanks Tom.
Got any sources for USP grade hydrochloric acid? |
Bill Pierce
Moderator
Username: Billpierce
Post Number: 10243
Registered: 01-2002
Posted From: 24.141.103.148
| | Posted on Sunday, April 26, 2009 - 04:49 pm: |
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It's hard to find a source for homebrewing chemicals. The suppliers are trying to avoid criminal liability from selling to individual customers who make meth or explosives. |
Tom Meier
Advanced Member
Username: Brewdawg96
Post Number: 900
Registered: 03-2003
Posted From: 75.76.167.200
| | Posted on Sunday, April 26, 2009 - 07:39 pm: |
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mikel,
I have found that food manufacturing plants are good sources for USP acids; big ones with labs. I've not found a commercial source for HCl.
I had some high % HCl acid, in a sealed HDPE bottle, also sealed in an old keg for safety. Just the fumes that diffused through the HDPE rusted out the keg, its mighty powerful stuff.. |
mikel
Member
Username: Mikel
Post Number: 230
Registered: 02-2001
Posted From: 4.246.208.178
| | Posted on Monday, April 27, 2009 - 05:56 am: |
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I find it frustrating that there isn't a cheap and plentiful source of food grade acids for adjusting PH. The phosphoric acid that the major homebrew shops sell is only 10% and expensive for 90% water. The lactic is more reasonable. I would like to try hydrochloric and sulfuric and have found several online sources for sulfuric that claim it is over 99% pure sulfuric acid. It is listed as "technical" grade which I assume isn't "food" grade. What could possibly be in the less than 1% that could be harmful?
I remember some years back talking with a friend of mine who owned a brewpub. He was talking about using muriatic acid to clean the kettle. He called the company who produced the acid he got at the local hardware store to ask if it was "food" grade. According to him the person laughed at the question explaining that the only difference in their "food" grade muriatic was that they were required to wear hair nets while it was being packaged. When I looked up the MSDS of the muriatic acid from my local hardware store it lists hydrochloric acid at 31.85% with the remainder H20. What could be in there that's not "food" grade? |
Dan Listermann
Senior Member
Username: Listermann
Post Number: 6583
Registered: 03-2004
Posted From: 74.83.191.159
| | Posted on Monday, April 27, 2009 - 08:07 pm: |
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Hydrochloric acid? |
Bill Pierce
Moderator
Username: Billpierce
Post Number: 10248
Registered: 01-2002
Posted From: 24.141.103.148
| | Posted on Monday, April 27, 2009 - 08:40 pm: |
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Some acids (for example, concentrated HNO3, H2SO4 and HCl) are relatively dangerous and require rather strict precautions, although with proper measures such as skin and face protection it's possible to use them safely. Other acids such as phosphoric and lactic acid are widely used by food processors yet are unavailable to the general public except from homebrew suppliers in small quantities at high prices. You should be able to buy these weak acids (in the chemical sense rather than the actual concentration) for about $5 a liter. Unfortunately no one seems to be selling them. The market is apparently not large enough for someone to take advantage of the opportunity.
Some years ago I knew a biochemist homebrewer who used 18 molar concentrated H2SO4 from his lab at work. Obviously he was a professional, but he said it gave him the greatest effect from the least amount. |
mikel
Member
Username: Mikel
Post Number: 231
Registered: 02-2001
Posted From: 4.246.208.180
| | Posted on Tuesday, April 28, 2009 - 03:48 am: |
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FWIW, I called the company of the muriatic acid sold in my local hardware store to ask what grade it was. I was told it is "technical" grade and they did not recommend using it for food production. I was also told that nobody exclusively produces hydrochloric acid for the purpose of selling it and that all hydrochloric acid sold is leftover from other manufacturing processes. I asked what could possibly be non-food grade about their product and was told they haven't a clue other than the fact that what they buy and repackage is "technical" grade. They did warn me that buying food grade hydrochloric would cost allot more due, in part, to the lengthy amount of paperwork and inspections that are required for the labeling of food grade.
Yes Dan, hydrochloric acid. The reason is because while reducing the alkalinty it leaves behind a chloride ion which is favorable to beer flavor. Sulfuric leaves behind a sulfate ion. Phosphoric, to my tastes, reminds me of soda pop and lactic also has it's own unique taste. I've heard that many British brewers use sulfuric acid for ph adjustment because the only flavor associated with it is the sulfate ion. |
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