pH, fullvolume mashing, calcium additions..

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jaroporter
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pH, fullvolume mashing, calcium additions..

Post by jaroporter » Tue Sep 13, 2016 11:57 am

hey, been having a bit of an an experimental session trying to confirm things regarding alkalinity and mash pH, and have hit a coupla problems i could do with a second(, third, fourth..!) opinion on..

1.)
for full volume mashing, i've seen that you really need to get liquor alkalinity much lower than the usual recommended figures to hit the pH range. interestingly, even a high proportion of roastmalt doesn't seem to have such an effect. after some sample mashes that came out quite high, i mashed 2kg pale malt with 12L water with an alkalinity reduced to just 5ppm CaCO3, which is a fairly standard BM10 ratio. conveniently this is the same ratio i use for fullvolume mashing in the large coolbox i have, though i know many BIAB brewers go as far as 1:9 kg/L.

samples throughout the mash were consistently around the pH 5,66 area, which i think is really the top end of where i want to be? if i wanted to get it lower i'd be adding more acid and ending up below 0ppm. which i couldn't measure with my KH kit and don't even know if it'd have the desired effect. any thoughts on this?


2.)
tried slaked lime treatment, basically following the guide on braukaiser website. it suggested that it would reduce calcium levels and you'd need to add more for the mash (as suggested in the water treatment section here also). it suggested adding this before the slaked lime treatment.

when i tested the alkalinity after slaked lime treatment it was off the scale. as in, increased. having now i think read that some people use calcium to increase alkalinity in mineral deficient water, i am wondering about this step. i have reduced alkalinity with acids before. was adding calcium to the mash then counterproductive?


thanks in advance for any help..
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Matt in Birdham
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Re: pH, fullvolume mashing, calcium additions..

Post by Matt in Birdham » Tue Sep 13, 2016 1:06 pm

I also full volume mash (exclusively, now). You are probably going to need more than just a low alkalinity to get mash pH where you want it for pale beers - I typically end up adding 75-150g of acidulated malt. I add in increments after testing pH, but I use the EZWater spreadsheet to get a ballpark idea of how much I am going to need. I treat the full volume of my mash water before mashing in with and gpysum or other minerals that I might be using.

I also use lime softening, and use the calculated values from the Kaiser water calculator spreadsheet (I have tried the "add and measure pH" method before, but find simply using a calculated amount of slaked lime to be quicker, easier and just as effective). How long after adding the slaked lime did you measure the alkalinity ? It will typically measure high whilst the calcium is still in suspension, and I always leave mine for at least 48 hours before testing/brewing. I consistently reduce alkalinity from ~240 to 20-30 ppm as CaCO3 using this method. Although the use of slaked lime to reduce alkalinity seems counter intuitive, the science behind it is all explained on the brakaiser website and it is a technique that breweries have been using for many years (centuries?).

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Re: pH, fullvolume mashing, calcium additions..

Post by jaroporter » Tue Sep 13, 2016 1:24 pm

cheers Matt that's really helpful. i did think about acidulated malt, but figured it'd be the same kinda unknown as adding acid past zero alkalinity. i'll check out that spreadsheet though. may come down to doing a few 10L test batches to dial it right in..

i tested the lime after i think around 24hrs which i had thought should have been enough, but i will try again leaving it longer as well. as said, i did add a lot of calcium chloride in, as i wanted to get to ~150ppm for the mash and boil, and it suggested to do this before treating with slaked lime.
i wasn't so much questioning the slaked lime method, as the calculation that it left me with no calcium so i had to add more, which seems to have increased alkalinity. it was only my first try with it though so i may have not quite done things right. i'll try it again i think without the CaCl2 to rule that out as an issue.
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Re: pH, fullvolume mashing, calcium additions..

Post by Matt in Birdham » Tue Sep 13, 2016 1:45 pm

I wonder could you be adding too much slaked lime? I think too much will rapidly start to increase alkalinity, although to be honest I am not certain on that (it will certainly raise the pH very high). I typically use about 10g in 45l, along with a pinch of chalk dust. I don't measure/use it until it is crystal clear, which does usually take a little more than 24 hours. I also read somewhere about using warm water to achieve more alkalinity reduction, and this seems to be true - I use hot water from the tap now, probably 50C or so. I think it is worth persisting with as it is a really useful technique - I am actually thinking of brewing a pilsner this winter as I think I could get away with it (I have low Cl and SO4 to start with, but moderate alkalinity at 240ish).
FWIW my starting calcium is about 100ppm and kaiser water says I should have a surplus of ~30, so I don't add anyting before softening other than a campden tablet.

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Re: pH, fullvolume mashing, calcium additions..

Post by Aleman » Tue Sep 13, 2016 1:52 pm

Again there is confusion between alkalinity and hardness, Alkalinity is the level of 'Carbonate Species' and, technically, hydroxide ions in the liquor, and hardness is the level of calcium and magnesium ions in the liquor.

For the vast majority of styles you need a low (ish) alkalinity, but can get away with quite a high hardness. Indeed in very 'soft', low alkalinity water even a 100% pilsner mash can end up with a pH of around 5.8. Add calcium (say 75ppm) and that pH falls down to 5.3-5.4, I know this for a fact, as I see it every time I brew! ;)

I've recently moved over from 3V brewing to Full Volume BIAB (via a braumeister) and what I've noticed is that with my typical wheat grist (3000g wheat malt, 2000g pilsner malt) and 32L of liquor, if I use an alkalinity of 30, and around 75ppm calcium I get a pH of 5.6ish (5.66 last observation), dropping the alkalinity to 15 using acids and adding calcium to 75ppm I get a mash pH of 5.4.

My water is very soft, usually 18-28 calcium and 25-40 alkalinity. I normally use calcium chloride and gypsum to add calcium.

If using the slaked lime treatment, it's important NOT to overdo it, as you will be adding alkalinity. I would always recommend using it to remove no more than 2/3rds of the excess alkalinity, and then use an appropriate acid (hydrochloric or sulphuric) to remove the remaining excess alkalinity. In all cases, using an alkalinity test kit at each stage to confirm that the alkalinity is where you expect it to be, is a good idea. Once you know what works then you can start playing around with 'test' mashes to determine what alkalinity and salt additions work for your 'standard' grists. Ant is right about raising the temperature to hasten the reaction, but still best to give it 48 hours to precipitate.

I normally take 100g of grist, 600ml of liquor, mix, stand at 65C for 10 minutes, then take the pH . . . as the volumes are so small, and the time so short I can run 8 different additions/combinations in one go.

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Re: pH, fullvolume mashing, calcium additions..

Post by jaroporter » Tue Sep 13, 2016 2:41 pm

there could be the possibility of having overdone it on the lime i guess, as i was doing trial 4L batches so the amount of lime needed was very small. i will try again with a full batch amount of water. my starting alkalinity is 230-240ppm so similar to yours Matt.
thanks for the clarification on the calcium addition. there's a lot of conflicting stuff out there you can read and tie yourself in knots with when you're looking for answers!

specifically for this last batch, i did test my untreated water with a salifert kit and it has a calcium level of about 85ppm, and i then treated with acids (AMS) that should have left this calcium untouched right?
so for a similar batch to the one Aleman used as an example above i was still coming in with a pH around 0,3 higher. is there something else i've missed that i should be looking at then to improve this?

having calibrated and checked the meter a few times in between samples i'm fairly sure that's okay..

thanks again for your time
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Re: pH, fullvolume mashing, calcium additions..

Post by Matt in Birdham » Tue Sep 13, 2016 3:12 pm

You could measure the pH of your lime-treated water, if you still have it. If it is > 10, you added too much lime. I find that with accurate scales, water measurement and pre-treatment alkalinity test, results are very consistent when using the additions calculated on the kaiser spreadsheet.

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Re: pH, fullvolume mashing, calcium additions..

Post by Kev888 » Tue Sep 13, 2016 5:44 pm

Yes, a lower mash liquor alkalinity is indeed needed for full volume mashing. I'm quite new to doing this, but so far about 10ppm to 15ppm below the norm for standard mash ratios is working well for me.

It seemed in the example #1 of the OP that a light grist was used, the PH achieved was noticeably less than 5.8 and there was still 5ppm total alkalinity in hand (e.g. for use of even paler malt or lowering PH further). That seems quite a useful result to me; is there a reason to fix anything?
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Re: pH, fullvolume mashing, calcium additions..

Post by jaroporter » Fri Sep 16, 2016 12:19 pm

Kev888 wrote:That seems quite a useful result to me; is there a reason to fix anything?
i guess i've so far understood that around pH 5,4 is where i want to be aiming, although a bit higher is fine - but this seems to be a bit over the range. also i'm interested in what else might be affecting results as a similar mash for me to the one Aleman mentioned (alkalinity, calcium, grist, etc.) came in a fair bit higher for me (~0,3).

i retried the slaked lime treatment and after 48hrs got much better results..
3,1g slaked lime in 15L liquor
starting alkalinity: 240ppm
finishing alkalinity: 60ppm

i also added some calcium chloride, slightly less calcium precipitated than calculated and i finished with 115ppm calcium going into the mash
so that seemed to go better with a larger volume. i'll probably play around with exact amounts of lime in future to see the effect but i think it probably worked out less lime overall and easier to measure so i think that may have been a good shout guys.

i used AMS to drop off the last alkalinity to <5ppm. just mashed it in again with a 100% pale grist and got a similar pH (5,64-5,72 start-end)

i guess acid malt (is it just pale malt sprayed with lactic acid?) is a similar thing to adding more discrete acids, but easier to measure beyond zero alkalinity? might be worth few grams to try..

appreciate all the thoughts/comments so far :)
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Re: pH, fullvolume mashing, calcium additions..

Post by Aleman » Fri Sep 16, 2016 12:50 pm

Anywhere between 5.3 and 5.8 will make pretty damn fine beer.

If you want to be completely anal about it then you might want to be dropping to 5.2 (???) to 5.5 for pale beers and using 5.5 to 5.8 for dark ones.

Remember that these pH values are quoted for a sample measured at 20C, and taken at 10 minutes after mashing in. pH will rise during the mash, that is normal, and acceptable.

Acid malt should only need to be used in a limited range of styles, and a limited range of situations, unfortunately it appears to be a general panacea to all sorts of beers according to a certain water calculator . . . as is requiring the mash pH to be down in very low regions.

Put down and walk away from the spreadsheet/program, and do some real world tests / batches :lol: :lol: Who knows you actually may find an approach to water treatment that works well for you and is completely different to what the authorities tell you ;)

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Re: pH, fullvolume mashing, calcium additions..

Post by jaroporter » Fri Sep 16, 2016 2:07 pm

fair enough. that's essentially what i've been trying to do this week. not sure what calculator you mean, i've really been following the basic alkalinity adjustment / add calcium from the water treatment pages here. just i've read on here a lot of people aiming for a lower pH than i seemed to be getting, but if i'm in range then great and that'll do me. just had an odd edge to some beers recently (or maybe just noticing it on less hoppy beers) so want to eliminate any glaring errors. cheers again for the time
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Re: pH, fullvolume mashing, calcium additions..

Post by Kev888 » Fri Sep 16, 2016 2:37 pm

The homebrew world suffers from perpetuated mistakes through some sources confusing the temperatures PH was or should be measured/quoted at, in addition to the usual differing opinions and international preferences. Probably not helped by a well known stabilising product that implies people should always want ph 5.2 for some reason, not that it works anyway in my experience. But minor differences aside, if you are between ph 5.3 and 5.8 at 20c then this shouldn't be the cause of your 'edge', it would most likely be something else.
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Re: pH, fullvolume mashing, calcium additions..

Post by Aleman » Fri Sep 16, 2016 5:02 pm

jaroporter wrote:I've really been following the basic alkalinity adjustment / add calcium from the water treatment pages here. just i've read on here a lot of people aiming for a lower pH than i seemed to be getting
If your alkalinity is in the right place, and you have sufficient calcium then your mash pH will fall in the ideal range. Personally I use my treatment, if the pH is higher than I want, then I adjust the treatment for the next batch. My 3V treatments for my usual grists give a good staring point for the BM and I get acceptable pH for the mash . . . But I am tailoring them slowly for the BM.

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