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PH buffers

PostPosted: Sat Dec 19, 2015 6:16 am
by Mash
Can you taste it?

Has anybody done any side-by-side fermentations?
I have seen in other posts, people using 50g citric acid & 50g sodium bicarbonate.

Off flavours are often caused by stressing yeast. so my thinking is slow and gentle is probably most neutral. Dunno.

The commercial wine world is changing its thinking. Instead of providing some nutrients to guarantee fermentation, they now aim too provide the optimum nutrition package. Which is a different view, and has already started a movement away from DAP

Re: PH buffers

PostPosted: Sat Dec 19, 2015 9:00 am
by hampk
And I'm one of 50g users, Mash! It works for me is all I can say. I started buffering as my washes were taking ages - two or three times what the methods reckoned. I changed from lentils to your wheat wash shortly after - that seemed to have far more effect on taste than the buffer.

One day I might do what you suggest and run two identical washes - one with, one without - but I suspect the only noticeable difference would be fermentation speed..

Cheers

Hampk

Re: PH buffers

PostPosted: Sat Dec 19, 2015 1:48 pm
by Phantom
Ok, so I'm obviously being thick and don't quite follow what you're alluding too.

Yeast likes an acidic environment. There's much conjecture from many of the different places as to just how acidic the environment needs to be.

Take mead as an example. The base honey doesn't seem to be very acidic from taste, which is very sweet. If you then dilute it down to a level where fermentation can take place (generally calculated using the gravity measurement scale), then when you make a measurement of the pH, the must still tastes pretty sweet but the reading you get (whether done with litmus paper or a digital pH meter) is surprisingly low.

There's a few chemistry type reasons for that, but if you find that it's too low, you can use a pH buffer to bring the numbers up some (my pH modifier of choice, is potassium carbonate - known to be the most efficient and least likely to add any taste notes).

In the original post by Mash, it seems to allude to using both an acid and a base. This, theoretically, would cancel out the possible action/result of using both. Hence my confusion........

When I use an acid to modify a finished flavour, I try to use an acid that is sympathetic to the ingredients where possible - though it depends on what's actually being made (is there such a thing as a sympathetic acid for a sugar wash ? probably not ;D ).

In any case, you wouldn't use both, an acid and a base. One or the other depending whether you needed to drop or increase the pH value.......

Re: PH buffers

PostPosted: Sat Dec 19, 2015 5:18 pm
by chill
A buffer is a combination of an acid and a base and functions differently than the two separate components. I don't know how adding them separately to the wash works. If you mix baking soda/sodium bicarbonate and citric acid, stir it, and let it sit, you can see a chemical reaction take place. It goes from a stirred mixtures of two different powder shapes to a a consistent crystalline structure that then solidified into a hard mass. This is sodium citrate. And it is what (some) bath bombs are made of. ;D

It is the sodium citrate that is a buffer, which is a chemical compound that in solution acts to keep the pH in a very narrow range.

Re: PH buffers

PostPosted: Sat Dec 19, 2015 5:50 pm
by hampk
+1 Chill - without the buffer, the pH in my washes drops dramatically and the fermentation stalls or at least slows to a crawl. With the buffer it seems to complete much more quickly.

I mix my citric/bicarbonate but dump it into a litre of cold water before it goes hard - looks spectacular and chemically achieves the same result.

Cheers

Hampk

Re: PH buffers

PostPosted: Sun Dec 20, 2015 12:52 am
by Easydrinker
Phantom wrote:Ok, so I'm obviously being thick and don't quite follow what you're alluding too.

Yeast likes an acidic environment. There's much conjecture from many of the different places as to just how acidic the environment needs to be.

Take mead as an example. The base honey doesn't seem to be very acidic from taste, which is very sweet. If you then dilute it down to a level where fermentation can take place (generally calculated using the gravity measurement scale), then when you make a measurement of the pH, the must still tastes pretty sweet but the reading you get (whether done with litmus paper or a digital pH meter) is surprisingly low.

There's a few chemistry type reasons for that, but if you find that it's too low, you can use a pH buffer to bring the numbers up some (my pH modifier of choice, is potassium carbonate - known to be the most efficient and least likely to add any taste notes).

In the original post by Mash, it seems to allude to using both an acid and a base. This, theoretically, would cancel out the possible action/result of using both. Hence my confusion........

When I use an acid to modify a finished flavour, I try to use an acid that is sympathetic to the ingredients where possible - though it depends on what's actually being made (is there such a thing as a sympathetic acid for a sugar wash ? probably not ;D ).

In any case, you wouldn't use both, an acid and a base. One or the other depending whether you needed to drop or increase the pH value.......


Not so much being thick here mate, as being on my side of the fence.
I think that I understand the use of a buffer.
I prefer to check PH and adjust it if needed, different strokes and all that.
There is no one true way.

Robert.

Re: PH buffers

PostPosted: Sun Dec 20, 2015 12:57 am
by chill
The advantage of using a buffer is that you just "set it and forget it". It does not adjust pH so much as prevent it from changing (within reason). When I was using baking soda, I would add some, get to my desired pH, and then a day or two later have to repeat the process. In the meantime, the yeast was working in an environment that was more acidic than it prefers. Which is why I now have a preference for using a buffer. But both ways work and get us to the end result, as does waiting for a long time. And the end result is all that matters.

Chuck

Re: PH buffers

PostPosted: Sun Dec 20, 2015 2:03 am
by Easydrinker
Without wishing to piss anyone off here,chuck's post say's it all,and even though I don't consider myself a religious person, I just feel an Amen coming on,

Robert.

Re: PH buffers

PostPosted: Sun Dec 20, 2015 7:16 am
by Mash
Thanks chaps.

I better understand the chemistry now.
If there is little or no taste difference it sounds to me like I better have a go.

Re: PH buffers

PostPosted: Sun Dec 20, 2015 6:38 pm
by chill
There is probably a slight taste difference in the wash, but I try to not drink that. ;D I have not noticed any taste difference in the distillate.

Re: PH buffers

PostPosted: Mon Dec 21, 2015 12:42 am
by Easydrinker
chill wrote:There is probably a slight taste difference in the wash, but I try to not drink that. ;D I have not noticed any taste difference in the distillate.



LOL

Robert.

Re: PH buffers

PostPosted: Mon Feb 08, 2016 12:33 pm
by Mash
hampk wrote:+1 Chill - without the buffer, the pH in my washes drops dramatically and the fermentation stalls or at least slows to a crawl. With the buffer it seems to complete much more quickly.

I mix my citric/bicarbonate but dump it into a litre of cold water before it goes hard - looks spectacular and chemically achieves the same result.

Cheers

Hampk


Old chestnut I know, but I am finally going to have a go.

So can someone just check I have this right....

1. 5kg dissolved into 20l (final vol 25l)
2. Mix citric/bicarbonate with 250ml ?? in a jug wait for fizz to die down then dump it into fermenter.
3. Top up to 25l
4. Finally...pitch yeast.
5. Ferment at 18-20c 5-6 days done.

Re: PH buffers

PostPosted: Mon Feb 08, 2016 7:14 pm
by chill
Yes, except I mix the two powders dry and let them sit for a bit (a day) and then add them dry. I don't know if letting the reaction take place when dry vs mixing them in water makes a difference or not, but that is what I do. It also means you can mix up enough for several washes and store them for quick use later. It does harden up, so store individual wash amounts. Or buy a chisel.

Re: PH buffers

PostPosted: Mon Feb 08, 2016 8:37 pm
by Anavrin
Just out of intrest, how many grams of citric and bicarb are you guys using to make a buffer for a a standard 25 litre wash?

This is something I've never thought of doing, I normally wait for something to go wrong then adjust as needed with one or the other.

I read something over on HD the other day and a guy mentioned He got some stuff that kept the PH in check, I put it on my, to reaserch list but didn't think it would be this simple to make.

Re: PH buffers

PostPosted: Mon Feb 08, 2016 8:51 pm
by chill
I've switched to a 50/50 by weight measure and use around 110g per batch.