Distilled Water vs Demineralised Water for NaOH solution

[Chalkyt]

Can anyone tell me if demineralised water is suitable for making up a NaoH solution for titration. It seems that distilled water has been replaced by demineralised water in supermarkets, auto stores etc as it is cheaper and quite suitable for car batteries, preventing buildup of deposits in irons etc. As a consequence distilled water is hard to find and I have run out of it.

 

[CKuhns]

Demineralized water for NaoH titration is used in the labs I managed. It has been a few years since retiring but believe it is still used.

 

[Buckeye_Hydro]

"Demineralized" typically means "reverse osmosis water."

 

[dmtaylor]

For homebrewing purposes:

1) Nobody should be doing titration, and

2) Demineralized water is close enough to distilled water for our intents & purposes.

I mean, seriously, this sounds like Breaking Bad kind of stuff, and your beer isn't going to turn blue from any extra attention to detail. It's a nice fiction that just is never going to come true in real life.

 

[mac_1103]

There are two options at the grocery chain I usually go to. Distilled and "Drinking Water." The latter says "purified by reverse osmosis" on the label. They provide a water quality report on their website. The report includes 121 parameters. There are exactly four differences between the two products. One is pH (5.7 vs 6.0). The other three are cases where one product is reported as "not detected" and the other is barely above the minimum reportable level.

 

[Maylar]

For homebrewing purposes:

1) Nobody should be doing titration

Not entirely true. This is cider, not beer. Cider needs a bit of malic acid bite to be balanced. Knowing what you're starting with is a useful metric for dealing with acid adjustments later. Also, if the TA is north of 0.7 gm/ltr you might consider using 71-B to knock it down a bit.

I do TA for cider only.

 

[Chalkyt]

Yep, that is my reason for titration. If I do the el-cheapo Jolicoeur method with my apples I can get the mix of apples somewhere near the desired 6g/L. My el-cheapo approach involves grating an apple (cheese grater) then squeezing this through a bit of cheesecloth to get a teaspoon or so of juice. The CJ el-cheapo uses a 2.67ml juice or cider sample which titrated with say 2ml of 0.2N NaOH is 2 x 5 =10g/L. Even easier, but a bit less precise is a 1.34 ml sample where 1ml of 0.2 NaOH = 10 g/L... no arithmetic needed.

For final adjustment I use the Andrew Lea approach of a 6.7 ml sample and 0.1N NaOH where mls of NaOH = TA.

For my purposes, doing the el-cheapo lets me grind and press a mix of apples that should end up somewhere near 6g/L (e.g. a 50% yield of 6kg of Red Delicious apples @ 2.6g/L, 3kg of Granny Smith apples @ 10g/L, and 2kg of Ballerina apples @10g/L gives me 5.5 litres @ 6.0g/L... just right for my 5 litre secondary carboys after leaving a bit of primary sediment behind ).

 

[jerrylotto]

Demineralized or deionized or distilled, all good enough for brewing purposes including making up standardized solutions. If you want to double check things you can test pH and TDS - 7.0 and 0 respectively

PS - I challenge anyone to measure milliliters to two decimal places without pretty expensive electronic measuring equipment.

 

[Maylar]

PS - I challenge anyone to measure milliliters to two decimal places without pretty expensive electronic measuring equipment.

Count drops from an eyedropper...

Google says "With a drop being rounded to exactly 0.05 mL (50 μL, that is, 20 drops per milliliter)"

 

[jerrylotto]

Count drops from an eyedropper...

Google says "With a drop being rounded to exactly 0.05 mL (50 μL, that is, 20 drops per milliliter)"

Precision and rounding are incompatible.

 

[Maylar]

Precision and rounding are incompatible.

True. Fortunately I only need one digit for my purposes.

 

[mac_1103]

Count drops from an eyedropper...

...and then directly measure the volume of 10, 15, 20 drops, etc. Repeat several times. Put the data in a spreadsheet. IOW, empirically determine the drop size and variance. Don't take Google's word for it.

I challenge anyone to measure milliliters to two decimal places without pretty expensive electronic measuring equipment.

Expensive? Sure (by most common everyday definitions anyway). But you know, scientists and engineers had some pretty damned accurate measuring devices long before electronic was even a word. And you can get non-electronic sub-microliter pipettes for under $500 if it means that much to you. But anyway, why would a homebrewer ever need to measure milliliters to 2 decimal places?

 

[jerrylotto]

...and then directly measure the volume of 10, 15, 20 drops, etc. Repeat several times. Put the data in a spreadsheet. IOW, empirically determine the drop size and variance. Don't take Google's word for it.


Expensive? Sure (by most common everyday definitions anyway). But you know, scientists and engineers had some pretty damned accurate measuring devices long before electronic was even a word. And you can get non-electronic sub-microliter pipettes for under $500 if it means that much to you. But anyway, why would a homebrewer ever need to measure milliliters to 2 decimal places?

I was responding to the "1.34 ml sample" comment.

 

[Chalkyt]

Thanks for the comments. I am not getting hung up on the precision of measurements (i.e. two decimal places certainly isn't intended to indicate accuracy, that is just the way the maths works out).

The 1.34 simply comes from 134 g/mol (molecular weight of Malic Acid) divided by 100. So, while CJ suggests using "a bit short of 2.7ml" in his favourite procedure, I was taking the view that "a bit over 1.3ml" could also work as a rough measure if I want the mls of 0.2 N NaOH to directly indicate g/L of acid (in that case when using a 1 ml syringe, 0.1ml = 1 g/L of acid). After all I just want to use small samples to find out roughly what the acidity of the apples are so I can plan my blend.

BTW, yesterday I had a victory. I was in Canberra (big, big town) last week and scratched around in the large supermarkets, auto supply stores and major hardware places and couldn't find any distilled water, hence the demineralised water question. Then back here in our sleepy little town in the mountains with a supermarket, hardware store and a "Friendly Grocer", I popped into the "Friendly Grocer" for something else and lo and behold, tucked away on the cleaning shelf... 2 litre bottles of distilled water!!!

 

[Kees]

You can make distilled water at home with a water distiller. I have one, it works well. Before the energy price increases they would produce distilled water at similar costs as store-bought bottles.