Can I use Potassium Chloride or Potassium Sulphate as the coagulantfor making Tofu ?

Hi !

I am thinking of making tofu.

Regular coagulants for the soy protein to make tofu are Calcium
Sulphate (gypsum), Magnesium Chloride (nigari), or Magnesium Sulphate
(epsom).

My chemistry is really bad, so I need help. I am thinking of
substituting the Calcium or Magnesium in the coagulant process with
Potassium.

My question is, can I use Potassium Chloride or Potassium Sulphate
(potash) to be the coagulant for tofu ?

Would it be possible?

Would it be poisonous?

In message <ba292def-d494-4746-8f8e-73d2d1e3beaf@y18g2000pre.googlegroups.com>, hsyq8xg@gmail.com wrote:

> Hi !
>
> I am thinking of making tofu.
>
> Regular coagulants for the soy protein to make tofu are Calcium
> Sulphate (gypsum), Magnesium Chloride (nigari), or Magnesium Sulphate
> (epsom).
>
> My chemistry is really bad, so I need help. I am thinking of
> substituting the Calcium or Magnesium in the coagulant process with
> Potassium.
>
> My question is, can I use Potassium Chloride or Potassium Sulphate
> (potash) to be the coagulant for tofu ?
>
> Would it be possible?

I wouldn't bet on much coagulation, but I'm not a chemist.
Keep in mind that Ca and Mg are both column II; K is
column I.

> Would it be poisonous?

Not in reasonable amounts, and you'd have to use a LOT
of K to be dangerous -- enough that it would taste nasty.

--
| Shit happens. Sometimes it happens to you. |
+--- D. C. Sessions <dcs@lumbercartel.com> ---+

In article
<ba292def-d494-4746-8f8e-73d2d1e3beaf@y18g2000pre.googlegroups.com>,
hsyq8xg@gmail.com wrote:

> Hi !
>
> I am thinking of making tofu.
>
> Regular coagulants for the soy protein to make tofu are Calcium
> Sulphate (gypsum), Magnesium Chloride (nigari), or Magnesium Sulphate
> (epsom).
>
> My chemistry is really bad, so I need help. I am thinking of
> substituting the Calcium or Magnesium in the coagulant process with
> Potassium.
>
> My question is, can I use Potassium Chloride or Potassium Sulphate
> (potash) to be the coagulant for tofu ?
>
> Would it be possible?
>
> Would it be poisonous?

I am not a professional chemist but I think that I can help some.

The purpose of the salt is to discharge any residual charge on the
colloidal particles. This removes the repulsive forces and allows the
particles coalesce into larger particles (coagulation). Almost any
electrolyte solution should do that.

Potassium ion is not highly toxic, but it can interfere with the
functioning of nerves including those keeping the heart beating
properly. At the least, I would want to know how much potassium is left
in the tofu and how big a dose you get. Also run it by your doctor or
pharmacist to find out how much trouble you can get into. Certainly,
large amounts of the other substances you mention can get you into
trouble. It just depends on the dose.

Gypsum is not highly soluble. That would indicate to me that you do not
need high concentrations to coagulate. Certainly, epsom salts is not a
problem in lw doses. Larger doses will keep you visiting the bathroom. I
presume really large doses are harmful.

I believe that potash is potassium carbonate, not the sulfate.

Bill

On Apr 19, 10:02 pm, Yabahoobs <chendrik...@gmail.com> wrote:
> On Apr 19, 8:01 pm, "D. C. Sessions" <d...@lumbercartel.com> wrote:
>
>
>
> > In message <ba292def-d494-4746-8f8e-73d2d1e3b...@y18g2000pre.googlegroups.com>, hsyq...@gmail.com wrote:
>
> > > Hi !
>
> > > I am thinking of makingtofu.
>
> > > Regular coagulants for the soy protein to maketofuare Calcium
> > > Sulphate (gypsum), Magnesium Chloride (nigari), or Magnesium Sulphate
> > > (epsom).
>
> > > My chemistry is really bad, so I need help. I am thinking of
> > > substituting the Calcium or Magnesium in thecoagulantprocess with
> > >Potassium.
>
> > > My question is, can I usePotassiumChloride orPotassiumSulphate
> > > (potash) to be thecoagulantfortofu?
>
> > > Would it be possible?
>
> > I wouldn't bet on much coagulation, but I'm not a chemist.
> > Keep in mind that Ca and Mg are both column II; K is
> > column I.
>
> > > Would it be poisonous?
>
> > Not in reasonable amounts, and you'd have to use a LOT
> > of K to be dangerous -- enough that it would taste nasty.
>
> > --
> > | Shit happens. Sometimes it happens to you. |
> > +--- D. C. Sessions <d...@lumbercartel.com> ---+
>
> KCl is highly poisonous. Don't use it.


From Wikipedia --- http://en.wikipedia.org/wiki/Poison

"Intravenous injection of an unnaturally high concentration of
potassium chloride, such as in the execution of prisoners in parts of
the United States, quickly stops the heart by eliminating the cell
potential necessary for muscle contraction."

Keywords above are "Intravenous Injection" & "Unnaturally High
Concentration"

Unless all the potassium chloride got into the blood, and that guy
eats a truck load of tofu, I don't think his heart is going to stop
contracting.

The coagulation of the "vegetable casein" protein which forms tofu
depends on a di or trivalent positively charged ion linking the
protein molecules together into a large molecular network. Only ones
suitable for use in food are calcium and magnesium. But too much
magnesium is a laxative this leaves calcium it is usually added as
calcium sulphate or calcium chloride occasionally as calcium lactate
or acetate.

Bob M
www.molab.co.nz

I'd think vinegar or a bit of heat would work to form soy curd as
well.
I'd avoid the potassium chemicals. I've tried the potassium based
baking powders in the past and it alters the taste and not in
a favorable way. Though this does indicate the nervous
Nellies concerned that a trace of potassium will kill is
overblown and reflects a lack of understanding of
what is going to be eaten here that is the solid not the
liquid. If one drinks pickle brine don't be surprised
if one gets a trip to the ER for congestive heart failure
due to the excess NaCl. Don't drink brine whether it
contains Na+ or K+.

Potash ash is crude potassium carbonate as I recall.

I suppose potassium sulfate might work though the
working end of the deal if it works would be the sulfate
anion given it minus two charge. It likely would work.
I'd rinse the curd. The remain dose of potassium should
be pretty low, likely doing no more than replacing some
of the K+ which is lost in the processing of the beans.

The other issue would be the issue of the purity of
the various proposed salts here and what else they
might contain.

Sample carefully in case I missed something and it
is going to kill in larger doses ;-) Before you take
your next breath ask your Doctor whether it is safe
and whether it is good to continue. Hold that breath, now.



hsyq...@gmail.com wrote:
> Hi !
>
> I am thinking of making tofu.
>
> Regular coagulants for the soy protein to make tofu are Calcium
> Sulphate (gypsum), Magnesium Chloride (nigari), or Magnesium Sulphate
> (epsom).
>
> My chemistry is really bad, so I need help. I am thinking of
> substituting the Calcium or Magnesium in the coagulant process with
> Potassium.
>
> My question is, can I use Potassium Chloride or Potassium Sulphate
> (potash) to be the coagulant for tofu ?
>
> Would it be possible?
>
> Would it be poisonous?

In message <f27917c0-d46b-4571-a512-a95e2b3e7334@e39g2000hsf.googlegroups.com>, trigonometry1972@gmail.com | wrote:

> I'd avoid the potassium chemicals. I've tried the potassium based
> baking powders in the past and it alters the taste and not in
> a favorable way. Though this does indicate the nervous
> Nellies concerned that a trace of potassium will kill is
> overblown and reflects a lack of understanding of
> what is going to be eaten here that is the solid not the
> liquid. If one drinks pickle brine don't be surprised
> if one gets a trip to the ER for congestive heart failure
> due to the excess NaCl. Don't drink brine whether it
> contains Na+ or K+.

Let's keep things in perspective here. The RDA for
potassium is 3000 mg. You can eat a potato without
danger of dropping over from the potassium content.

Morton "Lite Salt" is something like 40% potassium
chloride. I use the stuff all the time as a supplement.

--
| Shit happens. Sometimes it happens to you. |
+--- D. C. Sessions <dcs@lumbercartel.com> ---+

On Apr 19, 7:14 pm, hsyq...@gmail.com wrote:
> My question is, can I use Potassium Chloride or Potassium Sulphate
> (potash) to be the coagulant for tofu ?

No.

Dangerous Bill

On Apr 20, 8:10 am, "trigonometry1...@gmail.com |"
<trigonometry1...@gmail.com> wrote:
> ...Though this does indicate the nervous
> Nellies concerned that a trace of potassium will kill is
> overblown

Most people are okay, but certain people, or people taking certain
blood pressure medicines can develop heart irregularities.

But for the tofu thing, potassium is probably the last choice anyway.
Buy some calcium capsules and empty them (or crush up some drywall if
you want) and some epsom salts (magnesium sulfate).

Dangerous Bill

Yes, it seems there are medical outliers but they shouldn't dictate
what the rest of the population does. (I make this comment based
on all the products that dangerous to some section of the population
i.e. gluten, peanuts, corn, and so on.) For example, people on
kidney dialysis are placed on restrict potassium diets and
as other have mentioned some use KCL as salt substitute.
Even at that as I pointed out, potassium sulphate would largely be
washed
away provided the curd is rinsed. Assuming this even works.

Don't be silly.....crush drywall. Do you realize makers add
anti-mold additives to the stuff. I won't even put the
remainders from my dry wall work in hole in the garden, rather, I send
it to the land fill in the next state.

Bill Penrose wrote:
> On Apr 20, 8:10 am, "trigonometry1...@gmail.com |"
> <trigonometry1...@gmail.com> wrote:
> > ...Though this does indicate the nervous
> > Nellies concerned that a trace of potassium will kill is
> > overblown
>
> Most people are okay, but certain people, or people taking certain
> blood pressure medicines can develop heart irregularities.
>
> But for the tofu thing, potassium is probably the last choice anyway.
> Buy some calcium capsules and empty them (or crush up some drywall if
> you want) and some epsom salts (magnesium sulfate).
>
> Dangerous Bill

hsyq8xg@gmail.com wrote:
> Hi !
>
> I am thinking of making tofu.
>
> Regular coagulants for the soy protein to make tofu are Calcium
> Sulphate (gypsum), Magnesium Chloride (nigari), or Magnesium Sulphate
> (epsom).
>
> My chemistry is really bad, so I need help. I am thinking of
> substituting the Calcium or Magnesium in the coagulant process with
> Potassium.
>
> My question is, can I use Potassium Chloride or Potassium Sulphate
> (potash) to be the coagulant for tofu ?
>
> Would it be possible?
>
> Would it be poisonous?

I'd go for it if I knew how to make tofu. The worst that could
happen is that it would taste bad. Can you make it from soy milk?

--
Marshall Price of Miami
Known to Yahoo as d021317c

Bob M wrote:
> The coagulation of the "vegetable casein" protein which forms tofu
> depends on a di or trivalent positively charged ion linking the
> protein molecules together into a large molecular network. Only ones
> suitable for use in food are calcium and magnesium. But too much
> magnesium is a laxative this leaves calcium it is usually added as
> calcium sulphate or calcium chloride occasionally as calcium lactate
> or acetate.
>
> Bob M
> www.molab.co.nz

Do you know which soft drinks contain significant amounts of
phosphoric acid?

--
Marshall Price of Miami
Known to Yahoo as d021317c

Bob M wrote:
> The coagulation of the "vegetable casein" protein which forms tofu
> depends on a di or trivalent positively charged ion linking the
> protein molecules together into a large molecular network. Only ones
> suitable for use in food are calcium and magnesium. But too much
> magnesium is a laxative this leaves calcium it is usually added as
> calcium sulphate or calcium chloride occasionally as calcium lactate
> or acetate.
>
> Bob M
> www.molab.co.nz

By the way, Bob M has a discussion about phosphoric acid on his
website which confuses me:
http://www.molab.co.nz/pages/cola-osteoporosis.php . Any comments on
how he gets "50%" -- and what he means by it?

--
Marshall Price of Miami
Known to Yahoo as d021317c

On Sat, 03 May 2008 23:13:56 +0200, Marshall Price <d021317c@yahoo.com>
wrote:

> By the way, Bob M has a discussion about phosphoric acid on his
> website which confuses me:
> http://www.molab.co.nz/pages/cola-osteoporosis.php . Any comments on
> how he gets "50%" -- and what he means by it?

You mean 50% like in 50% neutralization? It means nothing. To get pH 5.5
you have to neutralize a little bit more than first proton, say 0.1M acid
plus 0.105M NaOH. If the 50% refers to real 50% - you end with perfect
pH=pKa2 buffer, that gives pH close to neutral (pKa2=7.2).

Borek
--
http://www.chembuddy.com/?left=BATE&right=pH-calculator
http://www.chembuddy.com/?left=Buffe...fer-calculator

Borek wrote:
> On Sat, 03 May 2008 23:13:56 +0200, Marshall Price <d021317c@yahoo.com>
> wrote:
>
>> By the way, Bob M has a discussion about phosphoric acid on his
>> website which confuses me:
>> http://www.molab.co.nz/pages/cola-osteoporosis.php . Any comments on
>> how he gets "50%" -- and what he means by it?
>
> You mean 50% like in 50% neutralization? It means nothing. To get pH 5.5
> you have to neutralize a little bit more than first proton, say 0.1M acid
> plus 0.105M NaOH. If the 50% refers to real 50% - you end with perfect
> pH=pKa2 buffer, that gives pH close to neutral (pKa2=7.2).
>
> Borek

This is still way over my head. Could you elaborate a little more?

--
Marshall Price of Miami
Known to Yahoo as d021317c

On Tue, 06 May 2008 08:38:03 +0200, Marshall Price <d021317c@yahoo.com>
wrote:

>>> By the way, Bob M has a discussion about phosphoric acid on his
>>> website which confuses me:
>>> http://www.molab.co.nz/pages/cola-osteoporosis.php . Any comments on
>>> how he gets "50%" -- and what he means by it?
>> You mean 50% like in 50% neutralization? It means nothing. To get pH
>> 5.5 you have to neutralize a little bit more than first proton, say
>> 0.1M acid plus 0.105M NaOH. If the 50% refers to real 50% - you end
>> with perfect pH=pKa2 buffer, that gives pH close to neutral (pKa2=7.2).

> This is still way over my head. Could you elaborate a little more?

Very generally speaking, phosphoric acid neutralization goes like that:

H3PO4 + 3NaOH -> Na3PO4 + H2O

50% means that you add half the amount of NaOH required. This in turn
means that you:
1. Proceed completely with first step of neutralization, ie
H3PO4 + NaOH -> NaH2PO4 + H2O
2. Proceed 50% into the second step of neutralization:
NaH2PO4 + NaOH = Na2HPO4 + H2O

So, after 50% neutralization your solution is 50/50 H2PO4- and HPO4-2.
This is a classic buffer solution, with pH described by so called
Henderson-Hasselbalch equation, which in this particluar case takes form:

pH = 7.2 + log([HPO4-2]/[H2PO4-])

but we already know that [HPO4-2] = [H2PO4-] (remember, solution is
50/50). That leaves us with

pH = 7.2

There are fine details omitted and hidden assumptions done so nitpickers
can bash almost every phrase in this post, but no matter how the'll try,
their final pH will be around 7 as well.

To get solution with pH around 5.5 you have to neutralize first proton and
add very small excess of base. I would call it 35% neutralization
(assuming 100% is when the amount of base is three times that of acid, to
account for the phosphoric acid "triprocity").

Now, you can define 100% neutralization in terms of single proton - ie
100% is when the reaction

H3PO4 + NaOH -> NaH2PO4 + H2O

is finished. That means full neutralization is 300%. This approach
sometimes simplifies calculations. Still, 50% in this case is when you
have 50/50 mixture af H3PO4 and H2PO4- - this is another buffer, with pH
around 2.2. No matter how you try it is NOT 5.5.

Browse pH calculation lectures at

http://www.chembuddy.com/?left=pH-calculation&right=toc

if you need more. Or play with pH calculator from

http://www.chembuddy.com/?left=BATE&right=pH-calculator

to see for yourself how the pH changes for different solutions. There isa
30 day free trial so you can do it for free.

Borek
--
http://www.chembuddy.com/?left=Buffe...fer-calculator

Borek wrote:
> On Tue, 06 May 2008 08:38:03 +0200, Marshall Price <d021317c@yahoo.com>
> wrote:
>
>>>> By the way, Bob M has a discussion about phosphoric acid on his
>>>> website which confuses me:
>>>> http://www.molab.co.nz/pages/cola-osteoporosis.php . Any comments on
>>>> how he gets "50%" -- and what he means by it?
>>> You mean 50% like in 50% neutralization? It means nothing. To get pH
>>> 5.5 you have to neutralize a little bit more than first proton, say
>>> 0.1M acid plus 0.105M NaOH. If the 50% refers to real 50% - you end
>>> with perfect pH=pKa2 buffer, that gives pH close to neutral (pKa2=7.2).
>
>> This is still way over my head. Could you elaborate a little more?
>
> Very generally speaking, phosphoric acid neutralization goes like that:
>
> H3PO4 + 3NaOH -> Na3PO4 + H2O
>
> 50% means that you add half the amount of NaOH required. This in turn
> means that you:
> 1. Proceed completely with first step of neutralization, ie
> H3PO4 + NaOH -> NaH2PO4 + H2O
> 2. Proceed 50% into the second step of neutralization:
> NaH2PO4 + NaOH = Na2HPO4 + H2O
>
> So, after 50% neutralization your solution is 50/50 H2PO4- and HPO4-2.
> This is a classic buffer solution, with pH described by so called
> Henderson-Hasselbalch equation, which in this particluar case takes form:
>
> pH = 7.2 + log([HPO4-2]/[H2PO4-])
>
> but we already know that [HPO4-2] = [H2PO4-] (remember, solution is
> 50/50). That leaves us with
>
> pH = 7.2
>
> There are fine details omitted and hidden assumptions done so nitpickers
> can bash almost every phrase in this post, but no matter how the'll try,
> their final pH will be around 7 as well.
>
> To get solution with pH around 5.5 you have to neutralize first proton and
> add very small excess of base. I would call it 35% neutralization
> (assuming 100% is when the amount of base is three times that of acid, to
> account for the phosphoric acid "triprocity").
>
> Now, you can define 100% neutralization in terms of single proton - ie
> 100% is when the reaction
>
> H3PO4 + NaOH -> NaH2PO4 + H2O
>
> is finished. That means full neutralization is 300%. This approach
> sometimes simplifies calculations. Still, 50% in this case is when you
> have 50/50 mixture af H3PO4 and H2PO4- - this is another buffer, with pH
> around 2.2. No matter how you try it is NOT 5.5.
>
> Browse pH calculation lectures at
>
> http://www.chembuddy.com/?left=pH-calculation&right=toc
>
> if you need more. Or play with pH calculator from
>
> http://www.chembuddy.com/?left=BATE&right=pH-calculator
>
> to see for yourself how the pH changes for different solutions. There is a
> 30 day free trial so you can do it for free.
>
> Borek

Wow. Thank you very much. (No wonder I didn't get it!)

When you say "full neutralization is 300%," is that because you need
three times as many molecules of NaOH (sodium hydroxide) as you have of
H3PO4 (phosphoric acid)? Why did you use NaOH in the example?

(Since I see phosphate groups so often in metabolic reactions, I was
surprised to read that the phosphoric acid in soft drinks might cause
problems.)


--
Marshall Price of Miami
Known to Yahoo as d021317c

Another silly question, Borek!

Molony says:

-----
Foods contain ... two groups [of acids];

[M]etabolisable acids ... which can be broken down and completely
destroyed For example citric acid, acetic acid, lactic acid etc.

And

[N]on metabolisable or fixed acids which are not destroyed by the body.
For example hydrochloric acid, sulphuric acid, phosphoric acid etc.
-----


Are these two categories simply (1) organic and (2) inorganic acids,
or is that too simple?


--
Marshall Price of Miami
Known to Yahoo as d021317c

On Thu, 08 May 2008 01:07:52 +0200, Marshall Price <d021317c@yahoo.com>
wrote:

> When you say "full neutralization is 300%," is that because you need
> three times as many molecules of NaOH (sodium hydroxide) as you have of
> H3PO4 (phosphoric acid)?

Yes, that's neutralization stoichiometry.

> Why did you use NaOH in the example?

Why not? Neutralization reactions are easiest to analyze when you use
strong acids/bases in calculations. NaOH or KOH are commonly used for that
purpose when speaking acid neutralization, HCl - when speaking about base
neutralization.

Borek
--
http://www.chembuddy.com/?left=BATE&right=pH-calculator
http://www.chembuddy.com/?left=Buffe...fer-calculator

On Thu, 08 May 2008 07:48:23 +0200, Marshall Price <d021317c@yahoo.com>
wrote:

> -----
> Foods contain ... two groups [of acids];
>
> [M]etabolisable acids ... which can be broken down and completely
> destroyed For example citric acid, acetic acid, lactic acid etc.
>
> And
>
> [N]on metabolisable or fixed acids which are not destroyed by the body.
> For example hydrochloric acid, sulphuric acid, phosphoric acid etc.
> -----
>
> Are these two categories simply (1) organic and (2) inorganic acids,
> or is that too simple?

It can work as a first approximation, but it is very likely there are
organic acids that'll will be not metabolised.

Borek
--
http://www.chembuddy.com
http://www.ph-meter.info

Borek wrote:
> On Thu, 08 May 2008 01:07:52 +0200, Marshall Price <d021317c@yahoo.com>
> wrote:
>
>> When you say "full neutralization is 300%," is that because you need
>> three times as many molecules of NaOH (sodium hydroxide) as you have of
>> H3PO4 (phosphoric acid)?
>
> Yes, that's neutralization stoichiometry.
>
>> Why did you use NaOH in the example?
>
> Why not? Neutralization reactions are easiest to analyze when you use
> strong acids/bases in calculations. NaOH or KOH are commonly used for that
> purpose when speaking acid neutralization, HCl - when speaking about base
> neutralization.

That's what I thought. (I'm trying to catch up on the chemistry I
missed when I dropped out.)

--
Marshall Price of Miami
Known to Yahoo as d021317c

Borek wrote:
> On Thu, 08 May 2008 07:48:23 +0200, Marshall Price <d021317c@yahoo.com>
> wrote:
>
>> -----
>> Foods contain ... two groups [of acids];
>>
>> [M]etabolisable acids ... which can be broken down and completely
>> destroyed For example citric acid, acetic acid, lactic acid etc.
>>
>> And
>>
>> [N]on metabolisable or fixed acids which are not destroyed by the body.
>> For example hydrochloric acid, sulphuric acid, phosphoric acid etc.
>> -----
>>
>> Are these two categories simply (1) organic and (2) inorganic acids,
>> or is that too simple?
>
> It can work as a first approximation, but it is very likely there are
> organic acids that'll will be not metabolised.

They'd be organic, but not carboxylic acids?

--
Marshall Price of Miami
Known to Yahoo as d021317c