Sciencemadness Discussion Board

Is milk acidic or basic?

Adas - 10-12-2011 at 06:10

Hello SM,

I have read, that milk is acidic and contains lactic acid, but I think it is not true, maybe it contains its salts. I personally think that milk is a little basic.
Thanks for your time.

Neil - 10-12-2011 at 06:14

Milk, like most things out of the body, is acidic.

http://www.miamisci.org/ph/hhoh.html


If you google "milk pH" you get several thousand results which all conclude the same.

Adas - 10-12-2011 at 06:20

Okay, thanks. The topic can now be removed

peach - 11-12-2011 at 05:11

Quote: Originally posted by Neil  

If you google "milk pH" you get several thousand results which all conclude the same.


I've done loads of googling but my mega penis make big cream still isn't working, must need to buy more of it.

Without further ado, the pH of various beverages I had to hand in the kitchen.

Milk, full cream, close to going off (I'd give it one more day)
<a href="http://img835.imageshack.us/i/img1869p.jpg/" target="_blank"><img src="http://img835.imageshack.us/img835/8109/img1869p.jpg" alt="Free Image Hosting at www.ImageShack.us" border="0"/></a><br>

Vimto, fruit cordial, 1cm's (about half an inches) worth made up with water
<a href="http://img703.imageshack.us/i/img1870o.jpg/" target="_blank"><img src="http://img703.imageshack.us/img703/2779/img1870o.jpg" alt="Free Image Hosting at www.ImageShack.us" border="0"/></a><br>

My tap water
<a href="http://img36.imageshack.us/i/img1871uu.jpg/" target="_blank"><img src="http://img36.imageshack.us/img36/973/img1871uu.jpg" alt="Free Image Hosting at www.ImageShack.us" border="0"/></a><br>

Tap water that has been run through a Brita water filter (activated carbon and ion exchange resin)
<a href="http://img847.imageshack.us/i/img1872zn.jpg/" target="_blank"><img src="http://img847.imageshack.us/img847/8678/img1872zn.jpg" alt="Free Image Hosting at www.ImageShack.us" border="0"/></a><br>

Cheers, I was enjoying that. Of coarse, the all time favourite, coke (diet cherry this time)
<a href="http://img39.imageshack.us/i/img1873v.jpg/" target="_blank"><img src="http://img39.imageshack.us/img39/8863/img1873v.jpg" alt="Free Image Hosting at www.ImageShack.us" border="0"/></a>

The crew of Das Boat enjoying a meal of lemons and the U-Boat Cocktail, condensed milk with lemon juice.
<iframe sandbox width="640" height="360" src="http://www.youtube.com/embed/AXiwCCcx7Zo#t=07m25s" frameborder="0" allowfullscreen></iframe>

Chemistry Alchemist - 11-12-2011 at 08:40

Page 45 on the Golden Book of Chemistry tells that Milk is about half way between pH of 6 and 7

Formatik - 27-12-2011 at 22:20

I recently tested the pH of raw egg yolk and found it to be very high, around 8.5. Whereas a sodium bicarbonate solution I made had a pH of about 8.0.

Adas - 28-12-2011 at 02:41

Quote: Originally posted by Formatik  
I recently tested the pH of raw egg yolk and found it to be very high, around 8.5. Whereas a sodium bicarbonate solution I made had a pH of about 8.0.


This is very interesting, thanks for your results! :o

peach - 29-12-2011 at 17:15

Quote:
Certainly the grade of the egg impacts its "quality"; however, there are many other conditions. Eggs are graded as a freshly laid egg. This freshly laid egg may be a AA or even a C graded egg to start with. However, all eggs will begin to deteriorate upon storage. The question and problem is to minimize storage losses. Storage in a room where temperature is maintained slightly above the freezing point [-2C; 28F) of eggs and humidity of 90% will maintain quality of eggs for several weeks. As temperature and/or humidity increases, the storage time will decrease. The following table indicates changes with storage and possible reasons for the change.

Change in Egg: Increase in pH

Reason For This Change: Carbon dioxide diffuses out of the egg. This may cause a rise from the fresh egg pH of 7.9 to as much as 9.3 in the white. The pH of the yolk is initially around 6.2 with little rise in pH. The carbon dioxide, a product of the metabolic pathways in the chicken, forms carbonic acid and bicarbonate buffers. These no longer exist when it diffuses out.

- Oregon State Food Resource, learnin' 'bout eggZ

Some more eggy weggy* trivia:

Quote:
When eggs are cooked for a long time, the yolk's surface may turn green. This is due to iron(II) sulfide which forms as iron from the yolk meets hydrogen sulfide released from the egg white by the heat.[2] This reaction occurs more rapidly in older eggs as the whites are more alkaline.[3]

- Wikipedia, Iron Sulphide

That reference [2] is, for once, free. Check it out if you want the ins and outs of green yolks.

Semen is basic with a range from 7.2 to 8. If it is made acidic, the tails of the sperm disconnect; making the sperm even more hopeless at steering than they were to begin with.

*No steaky wakey.

Hexavalent - 5-1-2012 at 14:47

Maybe this should go in the apparatus section, but peach - where did you get that chemistry multimeter?

peach - 7-1-2012 at 02:25

I can't remember the name of the place it came from as it was ages ago.

But Omega sell the same model.

I need to find a set of instructions for mine. I left them out at one point and, yeah... they're never coming back, lost to the dust bunnies. There are a number of ambiguously marked function buttons to access the settings.

Mine came in a blow moulded case with a ph probe, temperature probe, some test buffer bottles, the RS-232 cable and a CD with the software on it.

[Edited on 7-1-2012 by peach]

Hexavalent - 7-1-2012 at 14:06

Nice, but expensive. Did you buy yours new? Its seems to me like a sort of multimeter for chemists.

peach - 9-1-2012 at 02:00

I did buy it new.

It's useful because it has the ability to measure temperatures but, more interestingly, datalog. I can plug it in and let it sit there for 6h plotting a temperature curve to find the melting point of something; e.g. my bottle of acetic acid.

It is not exceptionally difficult to build your own datalogging pH meter with an electronics kit. And have it measure other things.

I didn't want to spend 12 months building mine (because I still can't get to grips with microprocessors) so I paid up the cash instead.

The level of resolution displayed on the screen is excessive. I do not need to know an absolute pH to 0.001 and I seriously doubt the probe and meter are capable of that anyway. That level of resolution is useful, however, to check if a pH is static or still changing.

The meters used to measure pool pH or the pH of hydroponic feed bins are fine for a lot of things. Those are on eBay for a few tens of dollars. But pH paper will work for quick checks and something being electronic does not necessarily mean it is more accurate.

Examples

Analog garden pH probe. $10?


The stoner special. $10-60


Someone better at programming than I, and their DIY pH logger. Very, very versatile (can reprogram it to measure, log and do just about anything) and cheap, but also requires knowledge of digital electronics and programming.


The PicoScope is designed to be a cheap multimeter / scope / datalogger with various inputs. It was originally aimed at schools and hobbyists. It is still quite expensive if all you want to do is check a pH. Few hundred.


Fluke 123 scopemeters will read a whole list of values and datalog, but not designed specifically for pH probes as far as I'm aware. About £1k new.


A black (in this case, grey) box datalogger. Many, many input channels.


Fluke 190, the leviathan of multimeters. Few thousand new.


A prebuilt version of the DIY option with the ability to measure from pH probes, thermocouples and other voltage / current sources. Nice big, colour, touchscreen interface. Datalogging to compact flash cards. 16 channels, up to 40kHz on the digital. Cole Parmer price is about £4k without the VAT I think; short of a lottery win, it'll remain gear porn for the hobbyist. Someone who was good with digital could recreate that for a lot less; at a guess, I expect they could do it for a few hundred. There are many cheap microprocessors and FPGAs that have many input pins, DACs, ADCs and output drivers for colour displays, as well as the ability to quickly add a card slot, USB or wireless interface.


The keys to developing these more expensive instruments, an Altium Nanoboard development kit. The fancy gear is usually something like this reboxed into a prettier housing. This is an example of a board the designer will prototype the device on, then (once it's checked) they'll send it off to have their own compact PCBs made for the production run. 3-4 hundred, endless uses.


[Edited on 9-1-2012 by peach]

Hexavalent - 13-1-2012 at 15:11

Thanks Peach!

What are your thoughts on this, everybody;

http://www.ebay.co.uk/itm/PH-TEST-Meter-Tester-Pen-Pool-Spa-...

??

Formatik - 14-1-2012 at 17:41

Thanks peach. So there is more to it than meets the Ei :P (Ei is the German word for egg pronounced the same as eye). Ar (little ar) :D.