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In many of my hot sauce making videos you will see me using a pH meter to test the acidity of the sauce. This is important from a safety perspective, especially when you are fermenting your chillies.
What is pH?

pH is the measure of how acidic or alkalei something is. The scale is from 0 to 14 (at least for our purposes). 7 is neutral, below 7 is acidic and above 7 is alkalei. It is a logarithmic scale which means that 4.0 pH is 10 times more acidic than 5.0pH, and is 100 times more acidic than 6.0pH.
We use the process of lactofermentation to ferment our chillies, this produces lactic acid which increases the acidity (decreases the pH). This results in a sauce that is safe, and tasty! For more information about the safety of your sauces and why the acidity is important, have a look here.
There are two main ways to test pH: pH Testing strips and pH meters.
pH Testing Strips

I see quite a few comments on my videos, and hot sauce discussion boards where people suggest using pH testing strips. I would not recommend these. Firstly the accuracy is not good enough (there is a big difference between 4.0pH and 5.0pH!). The main reason for not using these is because the sauce we are testing already has colour! Testing strips are best when testing water or transparent liquids.
pH Meters

Yellow generic pH meters
I have been through a few different pH meters, at varying price ranges. There are two things to make sure of when buying a pH meter. Firstly make sure that it is has Automatic Temperature Compensation (ATC), secondly it must be able to be to be calibrated (2 point calibration at least).
The first meters that I used were the yellow stick pH meters. They are made by many different companies and are priced around £10.
I still use this style of pH meter, but mainly for my hydroponics.
Essentials pH Meter

Because I was using my pH meter so often, I decided to upgrade to a new one. The next one I got was the Essentials pH Meter. This meter doesn’t require calibration as often and I get a fix on the pH a little quicker.
This was a worthwhile upgrade, but ultimately when both this and the previous pH meters are properly calibrated, they give the same results.

Apera Instruments PH20
The type of pH meter I use today is the Apera Instruments PH20. This is similarly priced to the Essentials pH Meter, but comes in a nice kit with some extras like the calibration solutions.
If I was going to upgrade again, I would need to make a fairly substantial increase in my budget. I am really happy with the Apera Instruments PH20 right now, and don’t have the urge to upgrade.
Whichever pH meter you buy, make sure you store the meter properly. Don’t let the tip get dry, this will ruin the device. You don’t need to use a lot of the storage solution, a few drops in the cap will be enough. And if you didn’t get calibration solution with your pH meter, make sure you get some. Because we are testing in the acidity range, you only need a 7.0pH solution and a 4.0pH solution for 2 point calibration.
Hi Chilli Champ,
Commenting here as there is no article about your ferminator.
You got small fan for hot air distribution inside fridge. Do you mix only internal air or have fresh air input.
Explain please.
This will help me in projects I’m in – edible mushroom cultivation, which might be also interesting for you.
Fresh air circulation and proper humidity is crucial for species like shitake. Oyster mushrooms are less sensitive. But your fridge fermintor idea would work great for both I think.
I am pretty sure I mentioned in the video, the fan is not for bringing external air in. It only turns on when the heating is on. It is there so that the heat distributes better inside the Ferminator, so there aren’t hot and cold spots.
Thanks!
Thank you for the ph advice I was concerned hot to clean them as I will be making hot sauces
Hi Chillichump, thanks for sharing this.
I have just ordered the same Apera PH20 device you use, and noticed the box doesn’t come with a storage solution. Is it essential to purchase this separately, or does this particular device not really need one?
Cheers!
Hey Jim, I would recommend getting some storage solution. This is the one I use: https://geni.us/phstorage
While you could get away with using a few drops of tap water…I would rather ensure the longevity and accuracy of it by using the proper stuff.