Electric Brewery's

[Scott H]

We spoke about creating a discussion so people who have or people who are thinking about and/or building can share pic's info and pitfalls to avoid.

Just about finished building my bench and hopefully will have a chance to start wiring it up this weekend. Pics to follow shortly.

[Rhys Williams]

I use citric acid.

It's amazing - 2 g in a 6Kg mash with 17L of water (there abouts) at a pH of 6.6sh can be dropped to 5.2 with about 2g of citric acid. I draw of, add citric acid, and recirculate, and measure, then adjust until mash is pH 5.

At 66c this is a real pH 5.3 - target is 5.2 - 5.6 sh.

I also match sparge water to the same pH as mash.

[Adam Sparks]

Thats really cool Rhys! Im curious what sort of probe your using? I haven't been able to find a probe that will go anywhere near mash temps without being destroyed int he process Even the expensive probes form the likes of blue lab are only rated to about 50c and I wouldn't go anywhere near that for the effect it has on their lifespan…. at $80 a pop its a pia to keep replacing them.

[Samuel Loader]

Hi, 

saw this post, I currently use this model of pH electrode which I have had now for two years without issue in testing my mash and boil pH. not sure if it will fit you current meter but most pH meters have the BNC connector  

http://www.eutechinst.com/pdt-type-electrode-lab-ecfg7451901b.html

not sure if Thermofisher NZ sells them but I know Alphratech NZ do 

[mattd2]

What is the price on one of those??? And what process connections available, can it thread into a pipe? And my final question - do you have to keep the probe wet??

[Samuel Loader]

I managed to get one cheap but Unfortunately these types of probes are about $300. and the only connection is a BNC, should be able to thread it into a pipe. ALWAYS keep them wet preferably with a 3.3 molar solution of potassium chloride ( water will drain the solution in the probe and reduce its life)    

[Adam Sparks]

So you stick this in boiling wort and its still accurate against calibration solutions? What meter are you using?

I also thought that single junction electrodes were not as accurate as double junction for our application due to the reaction of organic matter, proteins etc in the wort with the small amounts of silver in the probe?

Id love a more hardy probe though so will give anything a try! Thanks for the link!

[Samuel Loader]

I calibrate vs standard solutions (4, 7 & 10) at 20C and check each reading I take against litmus paper(just in case something is way off), these probes are used for field testing of farm run off water, mine run off water and used in the cosmetic industry for high temp products all of which contain proteins to an accuracy of about 0.05 pH so I have been told they are fine for brewer applications, considering we don't need to be quite that accurate as the mashing enzymes all have a optimum pH range of 0.5 pH between 4.5 and 5.8. and on the cold side yeast strains are quite happy in this sort of range.

[Adam Sparks]

sounds good to me, thats some price tag though!

[Rhys Williams]

I'm using a Wei Pro probe with a BNC connector I got from trade me for about $50. I can't find a current listing, but this is the probe:

http://www.fish-street.com/weipro_replacement_ph_probe_pen

Before I use it on the day, I calibrate in pH 4 solution and the pH 6.8 solution. This sets the 4.0 point and the slope of the probe. I have a small bottle for each calibration that I top up from a 250ml jar of each, as it is really easy to taint the solution moving from one to the other. You can get sachets of the calibration solution that make up 250ml of buffer when added to distilled water.

I never take the probe past 70c as I only want to know the mash pH. If you want to know at higher temperature you are better off cooling.

The probe comes with a container to keep the tip wet, the original storage stuff is long gone, I'm using the pH 4 buffer with a wee bit hyrdochoric acid to lower the ph down to 3.5sh.

I'm connecting to a raspberry pi ( see earlier post) via a board called MiniPh - this has the level converter on it gives me a digital i2c output, which I scale and calibrate using the solutions.

I've also recently added the temperature correction factor (approx .3 Ph for 66c vs 25c).

I've using it since January, and the calibration figures have not changed much, so I'm expecting quite a bit more life out of it.

I did use it trying to measure milk pH when I was making mozzarella once, and the proteins gunked it up. I had to put it high alkaline and the low pH to clean the probe, and it came right.

[Samuel Loader]

yeah, don't use it on milk ay those proteins are tough to get off, fonterra use a pepsin and hydrochloric acid solution to clean their pH electrodes.

your also right there is really no need to check it beyond mash out temp, so as long as you take really good care of them ( probe stored up right, in suitable storage solution when not in use and don't dry then with any sort of paper towels) you should get a couple of years out of them 

[Scott H]

Mark 2 of my panel built today photos to follow later , testing tomorrow. Have another 63L pot on the way so will start HLT construction next week got a birthday coming up so hopefully some cash coming my way will get me closer.

Have connected up the SSR's and removed the mechanical relays I had, is anyone else using the SSR's to directly switch the elements? The need for a mechanical seems pointless to me.

[Scott H]