New PH meter calibrates fine but takes forever to read RO water

[mabrungard]

So as far as I can tell....a reasonable practice to use acid with RO water is to put the acid in once mashed in? Otherwise the ph of the mash water could fall too low due to the lack of buffering? Before mashing in, adding and properly dissolving salts and taking a ph reading will help in predicting the amount of acid needed to add to the mash?

As AJ mentioned, definitely DON'T add acid to the mash since its very difficult to evenly distribute it. Add the precalculated amounts of acid and minerals to the strike water and stir the water well. That will assure those constituents are well-distributed.

With that acid addition in RO or distilled water, the strike water's pH may fall very low (maybe into the 4 range). That is an appropriate result and its not something to worry about. The buffers in the malt will raise the wort pH back into your intended range.

Don't try and chase wort pH by mashing in and then measuring. You are far better off with targeting a mash pH with software derived mineral and acid additions and then monitoring the resulting mash pH to see if the target for future batches needs to be adjusted up or down to meet your wort pH goal.

 

[ajdelange]

You will be better off still by "chasing" pH in a series of small test mashes. It is more work and takes more time than using brewing software but you will get a much better result than any software can give you. Software is OK for getting an estimate of the initial acid/base addition to try in a test mash and very good for teaching you what the effects of various additions of acids, bases and salts and malt choices may have but that's about it. Good mash prediction requires a good model of the chemistry and good models of the malts. There is only one program out there whose author seems to understand the chemistry (Brewers Friend) and even with that program the malt models aren't that good (nor can they reasonably be expected to be good).

 

[leesmith]

Here's what I did last night:

I used both Brewer'sfriend and Bru-N-Water to help calculate my acid addition for a ph of 5.3. They both were around the same amount recommended: around 2ml.

Once I had my water collected and salts dissolved in, I put half of the lactic acid in....so 1ml. The ph of the water dropped to 3.55. One thing about Brewer's Friend is that it has a section titled, "Mash Water Report Before Dough-In". And that predicted close to measured with a 3.6ph...although with half the recommended acid. So, one thing to shoot for may be that predicted "....Before Dough-In" ph. There's no harm in adding a little at a time to try and hit that number which may then correlate to the desired mash ph.

Once mashed in, 30 minutes into the mash I got a ph reading of 5.32.

AJ and Martin, thank you both for responding and giving some insight. AJ, while I lean more towards Martin's approach of brewing, testing, and then adjusting for the next brew, I really appreciate your recommendation of a mini-mash. With kids, a job, and all that adulting to do, it's hard fitting in a 6 hour brew day. Though I feel the mini-mash is the right way to do it given the quality and variation of ingredients...especially for home brewers.

The previous two mashes before this were off in regards to ph and I felt I needed to do something. This thread helped me understand a little more and gave me the confidence to try something new. This method may not always work but it got me there this time.

OH...and a plug for Buckeye Hydro...I have one of their RO units and it works great. Their customer service is good and I highly recommend them if anyone reading this thread is in the market for an RO unit.

 

[ajdelange]

I too advocate the measure and note for the future approach which is fine for the second, third.... iteration of a particular recipe. But where to start? Or what if you use a new malt? That's where a test mash is valuable. Also experience is a great teacher. To be honest I can't remember the last time I used one, if ever. But I do offer it to people starting out in this. Much of the time the available brewing programs will give you something that is reasonably close to what you want with the exceptions being the times they don't. As we say round the beltway "Trust but verify!"