Vinegar Au Naturel

[gregorach]

In preserving, you are relying on the combination of ingredients and method to destroy nasty bacteria and prevent them from re-establishing. The vinegar trick uses acid to create an environment hostile to bacteria.

... and that makes me wonder if the important test of a vinegar is checking it's pH value rather than speculating whether it may be strong enough on the likely balance of sugars in the starting product?

Wulf

If I was wanting to use homemade vinegar for preserving, yes, I'd definitely be checking both its pH and titratable acidity.

[MKG]

Apparently the pH value must be 4.6 or below for safe use in pickling.

Is there an easy way to determine that, Dunc? Or is it a trip to the chemist to buy some pH strips?

Mike

[boboff]

You can hot fill / steralise / pastuerise if it's higher than this, and get away with it. You also have the added advantage of getting a vacuum on your pickles which stops them leaking in hamper baskets!

Personally I prefer T***o Value Malt with added sugar, lush!

[gregorach]

Apparently the pH value must be 4.6 or below for safe use in pickling.

Is there an easy way to determine that, Dunc? Or is it a trip to the chemist to buy some pH strips?

Mike

I think you will need some kind of indicator, yes. (OK, I have a decent pH meter, but I very much doubt that many others do... )

I'd say pH test strips (preferably narrow-range) are probably the best option, but for the less chemically-inclined, it apparently is possible to make a pH indicator from red cabbage, which you can then calibrate against shop-bought vinegar.

I'm not sure that I'd be entirely happy relying on pH alone though - I know you can get a low pH with a relatively low level of titratable acidity if your water has very low alkalinity, and I suspect that adding vegetables to it could dilute it further and raise the pH beyond the safe limit. That's just off the top of my head though, might not be important, and I somehow doubt that our "no sugar, no yeast" friend here is going to want to get into doing acid/base titrations...

[Ellendra]

Here's an article that tells both how to make vinegar, and how to test it: http://www.countrysidemag.com/issues/83 ... Staff.html

[JT101]

I can't thank you all enough. You've even answered questions before I even thought of them!

That link posted by Ellendra was terrible. It's given me way too many ideas for future vinegars au naturel to make! Seriously, it's amazing. Has virtually everything the simple homebrewer like myself wants to know.

Based on the raspberry vinegar, I guess 3 months before pastuerising would be a good period of time before testing the taste and strength?

Thanks

[wulf]

I'm not sure that I'd be entirely happy relying on pH alone though - I know you can get a low pH with a relatively low level of titratable acidity if your water has very low alkalinity, and I suspect that adding vegetables to it could dilute it further and raise the pH beyond the safe limit. That's just off the top of my head though, might not be important, and I somehow doubt that our "no sugar, no yeast" friend here is going to want to get into doing acid/base titrations...

Could you give us a quick primer on titratable acidity? I vaguely remember doing titration at school but have long forgotten the details. In particular, is there a way to do this with home equipment?

Wulf

[gregorach]

Could you give us a quick primer on titratable acidity? I vaguely remember doing titration at school but have long forgotten the details. In particular, is there a way to do this with home equipment?

Wulf

Not exactly, but you can buy test kits from any decent homebrew shop or via the internet. The test procedure basically involves adding a pH indicator (chosen for a clear colour change at a particular pH value) to the solution under test, and then adding an alkali of known strength, dropwise, until the colour change is observed. The precise calculations required vary according to the indicator used and the strength of the alkali, but your typical winemakers test kit is formulated to make it nice and simple.

[JT101]

So does that sound reasonable, 3 months?

[MKG]

Assuming that you've already detected the unmistakeable vinegar scent, I'd guess that three months is plenty.

Mike

[JT101]

Ok great. I'll report back when it's done.

Thanks

[JT101]

I've been reading over this for the past couple of days, and it's finally clicked. I was getting mixed up between all the terms such as acetic acid, titrable acidity, etc

I would ideally test for percentage acidity AND pH for pickling purposes!

Must be >5% acidity, and <4.6pH.

Is it important to measure both or could I just get away with measuring the percentage acidity?

According to this link provided earlier: http://www.countrysidemag.com/issues/83 ... Staff.html, the percentage is critical.

[gregorach]

You can probably get away with just the percentage acidity, yes.

[JT101]

Thanks Dunc. All your expertise is much appreciated. As you know, I'm keen on the simplistic approach, so this means I can do the reb cabbage thing without having to buy many chemicals to test the percentage. Just baking soda I think, according to that link above. Almost completely self sufficient. Now............how to make baking soda