Author Topic: Adjusting Mash pH BIAB  (Read 1016 times)

Offline tdibratt

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Adjusting Mash pH BIAB
« on: February 02, 2018, 12:13:34 PM »
I have been reading up on the topic and looking around for some good instructions in practice for those of us who brew BIAB Ales/Lagers.

SO i get that because the water to grain ratio for BIAB is higher then conventional sparge techniques our pH will likely be on the high side (Alkaline).

So I turn on my electric kettle bring the water temps up, add the grains, set the re-circulation pump and set my temps to sat 154F.  I would normally let this run for 60 minutes.

Do I take a sample 15 mins in and adjust my pH based on that reading or should I wait till the end of the 60 minutes and before I start the boil phase to take a reading and adjust the water level?

Do I just need to make sure I have some Lactic Acid 88% on hand to lower it?  Just add little at time and keep testing with the test strips?  Once I am around 5.2 level, I can then proceed to the boil phase?

Thx

Offline Oginme

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Re: Adjusting Mash pH BIAB
« Reply #1 on: February 02, 2018, 01:07:41 PM »
I have been reading up on the topic and looking around for some good instructions in practice for those of us who brew BIAB Ales/Lagers.

SO i get that because the water to grain ratio for BIAB is higher then conventional sparge techniques our pH will likely be on the high side (Alkaline).

So I turn on my electric kettle bring the water temps up, add the grains, set the re-circulation pump and set my temps to sat 154F.  I would normally let this run for 60 minutes.

Do I take a sample 15 mins in and adjust my pH based on that reading or should I wait till the end of the 60 minutes and before I start the boil phase to take a reading and adjust the water level?

Do I just need to make sure I have some Lactic Acid 88% on hand to lower it?  Just add little at time and keep testing with the test strips?  Once I am around 5.2 level, I can then proceed to the boil phase?

Thx

First, where your pH ends up is highly dependent upon your starting water.  Don't assume that the pH will be high because you have a greater amount of water in the initial mash infusion.  If your water, like mine, is pretty close to RO water it will have no buffering capacity and will adjust pretty quickly to reflect the pH contributions of the malts being used.

You can take a sample at 15 minutes, chill, and measure pH, then make an acid addition, but honestly, most of your conversion will be done by that time.  You can make an initial adjustment and then use that amount to adjust your water the next time.  I usually take a final pH sample and reading at the end of the mash and while the wort is heating up to the boil so that I can make any adjustments for the next brew session.  I have generally found that if I start somewhere in the 5.0 to 5.8 pH region at the start of the mash, it will be pretty close to 5.2 to 5.4 by the end of the mash. 

Making an adjustment after the mash is over doesn't help in improving enzyme efficiency since most of the enzymes are denatured or will be soon as you are raising the temperature of the wort.  I've read several articles on the effect of wort pH on the ending flavor of the beer, but honestly cannot comment on what affect and to what degree it does.

You can have some lactic acid on hand to make adjustments, but if you are in the prime range of 5.0 to 5.8, I would not recommend trying to adjust it.  I use mineral salts to adjust my water which I add the day before and have not used acid for pH control in years.  If I find that I am off from my target or estimated pH, I make a note to adjust for the next time and keep brewing.
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Offline GigaFemto

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Re: Adjusting Mash pH BIAB
« Reply #2 on: February 02, 2018, 01:35:55 PM »
In addition to the good advice from Oginme, look out for the acid recommendations from BeerSmith. It is well-known that they are too high by a factor of roughly 2. If you want a more accurate calculator, look at Bru'n Water (https://sites.google.com/site/brunwater/ ). If your water is consistent then you should be able to dial in your pH pretty well, and a measurement at 15 mins into the mash will confirm it for you. My pH is usually in the range 9.3-9.6, and Bru'n Water calculations based on that usually come out right on the nose. Last week my starting water was pH 9.9 and I had a very light grain bill so I had to add a bit more acid at the 15 minute mark.

The worst thing you can do is what I did when I first began measuring pH. On one batch I had added too much acid and the pH was too low so I added some baking soda. A few minutes later I measured again and the pH was too high so I added some acid. Then the pH was too low, and so forth.

Offline tdibratt

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Re: Adjusting Mash pH BIAB
« Reply #3 on: February 08, 2018, 08:13:22 PM »
So my water pH is about 7.5.  sounds like I should be adjusting it down some.  I tried to figure out Brun water and could not.  For a 5 gallon batches and about 12 to 13 pounds of grain should I get it down closer to six before I start?

Thx

Offline GigaFemto

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Re: Adjusting Mash pH BIAB
« Reply #4 on: February 08, 2018, 08:31:27 PM »
The pH of your starting water is not as important as the buffering capacity, which depends on the level of minerals in the water. You need a report on your water to know that and give Bru'nWater the inputs it needs. All municipal water districts in the USA are required to produce an annual water quality report, and most of these contain information on the items of interest to brewers as well as lead, bacteria and other items of health interest. If you can't get one of those you can send a sample of your water out to be tested to a lab (I have heard the name Ward labs mentioned, but I know nothing about them). If you don't want to deal with the time and expense of getting your water tested, then you will just have to guess or draw  your own conclusions based on measurements. You can try a mash with your typical grain bill (darker grains are more acidic than lighter grains), them measure your pH and try to figure out the alkalinity of your water based on the results so you can correct for the next brew. Since it depends on the grain bill, though, it is not a simple matter and that is why Bru'nWater is so valuable. If you have a water report but just can't figure out Bru'nWater then you can ask for help with that, but you need to post your water report and details on the grains in your recipe (i.e weight, type, Lovibond rating).

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Offline tdibratt

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Re: Adjusting Mash pH BIAB
« Reply #5 on: February 09, 2018, 02:01:01 AM »
My town water report is here

https://www.toronto.ca/wp-content/uploads/2017/11/914c-drinking-water-analysis-2016-AODA.pdf

I was trying to figure out what gets entered where on Brun water XLS.  If someone can help guide me.

Thx

Offline brewfun

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Re: Adjusting Mash pH BIAB
« Reply #6 on: February 09, 2018, 07:39:23 AM »
I was trying to figure out what gets entered where on Brun water XLS.  If someone can help guide me.

Your water quality report is very detailed! Moreso than most US cities. A report is a good starting point, but getting your particular tap water analyzed by a lab will yield the most accurate results.

Instructions are on page 0 of the spreadsheet and will give you better detail than a post here. You're simply looking for the ions listed on Page 1, as PPM (mg/L), which your report provides. Your report also handily provides alkalinity and hardness which will add accuracy.

The report has high/low/average results. You'll pull from the average column on all items. This may yield an imbalance, but it'll still work for calculating Residual Alkalinity (RA).

It appears that they're using Alkalinity as temporary hardness, so, this is the number to use for conversion calculations. You'll get your bicarbonate number by putting your alkalinity into cell A28. Your Carbonate number will remain zero. You won't need any of the optional ions (like fluoride) to balance your report.

My results showed TDS was within the range stated and using alkalinity yielded ions close to the average.



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