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-   -   Have a new pH meter, don't know what to do (http://www.homebrewtalk.com/f128/have-new-ph-meter-dont-know-what-do-345272/)

Gameface 08-02-2012 05:39 PM

Have a new pH meter, don't know what to do
I'm getting ready to brew and for the second time I'm not sure I'm going to bust out my new pH meter for this brew day. I just don't know how to use it correctly or what I would even do if my pH wasn't good.

Here are a few of my specific problems.
1) I'm scared of damaging the probe if I misuse it.
2) I'm scared of reacting to a false reading caused by not using the meter correctly.
3) I wouldn't know what to do if, let's say, my mash pH was 6.7.
4) I'm not sure how to set up a little pH testing station. Would I need several small cups that can hold the calibration solution, cleaning solution and whatever I want to sample? Can I use any old cup? Do they have to be cleaned and rinsed really well or just pretty well? etc.

Anyway. I'd really love to take advantage of my new piece of brewing gear and improve my brewing that little bit more, but I don't want my brew day to go off the rails while I fiddle with my new meter. Any advice on how you incorporate your pH measurements into your brew day would be greatly appreciated.

Gameface 08-02-2012 05:41 PM

Oh, and I'm sorry if there is an uber thread on this very subject already. I read up on using pH meters before buying one and have read a lot more since getting mine, but I'm still not comfortable incorporating this into my brew day. I really appreciate any help and or points in the right direction.

MachineShopBrewing 08-02-2012 05:58 PM

1. Don't put the probe in hot wort. Make sure to cool a small sample first. I use a small glass(pyrex) flask and immerse it in ice water.

2. As long as you calibrate, you should be fine. Take readings at different times and see what you get.

3. Your mash pH won't usually be that far off. Mash pH wants to be in a certain range naturally. If you made sugar last time, then your pH had to be close. I don't adjust my pH on brewday. I have never had it really wild. If a new recipe and it comes in a little low or high, then I just note that and adjust the water next time I brew with those kinds of malts.

4. Get yourself some little glass beakers or flasks for calibration solution and your sample. I also keep a spray bottle of DI water for spraying down the probe to clean it. I calibrate while heating strike water and then I am ready to go come mash time.

MachineShopBrewing 08-02-2012 06:01 PM


You can do a small test mash to predict what your possible mash pH will be for a recipe and then make adjustments there before you do the big mash. You could do this for all of your recipes that you like to brew and then you have the notes. There are a lot of days I don't even break out my pH meter because I know I will be good due to experience.

Gameface 08-02-2012 06:07 PM

Thanks for the info!

So if I snag a little wort from the mash I can mess around with my meter after the brew day is done? That sounds less stressful. When should I take the sample, a few minutes in or once I believe it is converted?

jmf143 08-02-2012 08:18 PM

Take a few samples at different times - 15 minutes into the mash, again at 30 minutes and a final one when you're done mashing. If your pH is too high you can use acidulated malt in your grist next time, or lactic acid.

Look for posts by ajdelange and mabrumgard for guidance.

afr0byte 08-03-2012 01:46 AM

This thread is useful: http://www.homebrewtalk.com/f128/ph-...ration-302256/

mabrungard 08-03-2012 02:02 AM

I recommend testing pH early in the mash since that is when much of the conversion is completed. Samples at 5 and 10 minutes would be more telling.

ajdelange 08-03-2012 04:40 AM


Originally Posted by Gameface (Post 4300585)
So if I snag a little wort from the mash I can mess around with my meter after the brew day is done? That sounds less stressful.

That's the ticket but I'd suggest doing pH checks on things like your tap water, milk, soda, orange juice, lemon juice, vinegar etc. at leisure before brew day to get yourself familiar with how readings are taken, how to handle the meter etc. Do read the Calibration sticky and perform the stability check to get an idea of how stable your electrode is.


Originally Posted by Gameface (Post 4300585)
When should I take the sample, a few minutes in or once I believe it is converted?

Part of the art is knowing when to take the reading. At first I'd say take several starting as soon as dough in is complete. If you are doughing in at a high temperature be sure to allow the wort to cool. Collect it in a small glass and immerse that in cold water. Monitor the temperature and insert the proble when temp is 20 - 25 C. Write down time, temperature and pH. As soon as you have the first reading get another sample and repeat. You will find (if things go the way they usually do) that the pH will drop fairly fast initially, then slow down and finally not change by more than 0.01 pH between readings after that. The final stable reading is the one you are after and you will be making adjustments to get that one into the target range (though probably on the next brew rather than this one). You are not trying to establish a pH after the conversion - you are trying to establish the pH that makes the conversion proceed most efficiently (where 'efficiency' here means not so much maximum conversion of starch but conversion that leads to the best finished beer flavors). You can also check pH at the end of conversion and should definitely check and record at the end of each step or at the time of return of each decoction if it is a programmed mash. You should also check going into and coming out of the boil and a few hours after pitching. These pH readings will serve as quality control mileposts for you on future brews.

RCCOLA 08-04-2012 12:01 AM

I did a brewday pictorial with my meter. See if this is useful to you. http://www.homebrewtalk.com/f128/ph-...y-pics-244963/

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