Lactic Acid 88% How much is too much to reduce pH

[scruffy40nil]

First post long time reader......
I've been brewing all-grain for over a year now using a 65L Brewzilla.
I'm very new at experimenting with water salt additions to the mash.

I'm a little concerned with the amount of lactic acid that my recipe from Brewfather calculated (16.8ml for a 50L batch) to bring down my pH level to 5.2pH.
Looking to brew tomorrow so I've already purchased my grain bill, concerned with the 16.8ml of lactic acid and if you'll be able to taste the acid in the finial product.

Below is my XPA recipe grain bill and salt addition.

78% Gladfield American Ale Malt
12% Wheat Malt Barrett Burston
10% Gladfield Vienna Malt

Starting water is Sydney (Ryde) water and target water is Yellow Dry (under 6 SRM) water profile from beer smith.
Mash Water Additions:
Calcium Chloride (CaCl2) 1.61g
Epsom Salt (MgSO4) 3.66g
Gypsum (CaSO4) 5.39g
Lactic Acid 88% 16.8ml

pH with Lactic Acid: 5.2pH
pH without lactic acid: 5.72pH

Mash water vol: 48L

Many thanks in advance.

 

[Sidney Harbour-Bridge]

I'm not sure of the exact chemistry but I would measure the pH before adding lactic acid as the water salts specified will reduce pH (I think)

 

[MHB]

Scruffy you need to know
The strength of the Lactic acid, 80%, 88% and 100% are all available, obviously the stronger the less you need.
The mass of malt, there is a pretty simple calculation for how much a given amount of Lactic will lower the pH of a known mass of malt. I posted the raw data from Kunze in another thread.
I see you have 88% Lactic acid, If your grain bill was say 9kg and given that 0.6mL of 88% Lactic will lower the pH of 1kg of grist by 0.1pH. To get from 5.7 to 5.2 you need a change of 5 of 0.1's
So 0.6*5*9 = 27mL (actually its 0.6 and a bit mills but better to add a touch less than to go too far)
That calculation is for a 100% base malt beer or close to, you calculator might be assuming the Vienna and Wheat are a bit more acidic so you need less Lactic, but I would go with what your are given and check it again.

I doubt there is enough there to affect the taste of the beer.
Mark

 

[scruffy40nil]

Scruffy you need to know
The strength of the Lactic acid, 80%, 88% and 100% are all available, obviously the stronger the less you need.
The mass of malt, there is a pretty simple calculation for how much a given amount of Lactic will lower the pH of a known mass of malt. I posted the raw data from Kunze in another thread.
I see you have 88% Lactic acid, If your grain bill was say 9kg and given that 0.6mL of 88% Lactic will lower the pH of 1kg of grist by 0.1pH. To get from 5.7 to 5.2 you need a change of 5 of 0.1's
So 0.6*5*9 = 27mL (actually its 0.6 and a bit mills but better to add a touch less than to go too far)
That calculation is for a 100% base malt beer or close to, you calculator might be assuming the Vienna and Wheat are a bit more acidic so you need less Lactic, but I would go with what your are given and check it again.

I doubt there is enough there to affect the taste of the beer.
Mark

Thanks Mark,
I'll check that post out now. That makes me feel much better. I didn't want to add too much, I was wanting to add some sour grapes malt to the grain bill to reduce the amount of lactic acid but couldn't get my hands on any in time.

Cheers

 

[duncbrewer]

@scruffy40nil

I use brewersfriend water calculator that likes to know total volume of water mash and sparge and then if salts only to the mash.
Further it will suggest acid addition for the sparge water as well to ensure the pH not too high and no tannin extraction occurs.
Seems like a lot of mash water to me I have a guten 70 so similar capacity and normally around 3 litre per kilo of grain so this suggests to me 16kilo of grain.
Volume of that grain and 48 litres is more than 65 litres I'd say so do be careful that you can fit it all in. I normally reckon to lose about one litre per kg of grain so that would leave about 32 litres and plenty to sparge with.

Difficult to know about the lactic acid amount without knowing the grain mass really.

 

[mynameisrodney]

I just put this into Bru'n water (assuming 10kg total grain) and that addition took the ph from 5.76 to 4.71.

I'm not claiming to be an expert at water chemistry, but I think its worth another check. EDIT: if 16.8ml is correct then I might need some help sorting out the spreadsheet haha.

 

[scruffy40nil]

@scruffy40nil

I use brewersfriend water calculator that likes to know total volume of water mash and sparge and then if salts only to the mash.
Further it will suggest acid addition for the sparge water as well to ensure the pH not too high and no tannin extraction occurs.
Seems like a lot of mash water to me I have a guten 70 so similar capacity and normally around 3 litre per kilo of grain so this suggests to me 16kilo of grain.
Volume of that grain and 48 litres is more than 65 litres I'd say so do be careful that you can fit it all in. I normally reckon to lose about one litre per kg of grain so that would leave about 32 litres and plenty to sparge with.

Difficult to know about the lactic acid amount without knowing the grain mass really.

@scruffy40nil

I use brewersfriend water calculator that likes to know total volume of water mash and sparge and then if salts only to the mash.
Further it will suggest acid addition for the sparge water as well to ensure the pH not too high and no tannin extraction occurs.
Seems like a lot of mash water to me I have a guten 70 so similar capacity and normally around 3 litre per kilo of grain so this suggests to me 16kilo of grain.
Volume of that grain and 48 litres is more than 65 litres I'd say so do be careful that you can fit it all in. I normally reckon to lose about one litre per kg of grain so that would leave about 32 litres and plenty to sparge with.

Difficult to know about the lactic acid amount without knowing the grain mass really.

total grain weight is 11.1kg
Mash Water: 47.5L
Sparge Water: 20.5L
Mash Vol (water + Grain): 55L
Final Batch Vol: 50.8L

Do you think it's too much mash water? I've scaled this recipe up from my 35L brewzilla.. Calculations all been created by brewfather.

 

[scruffy40nil]

I just put this into Bru'n water (assuming 10kg total grain) and that addition took the ph from 5.76 to 4.71.

I'm not claiming to be an expert at water chemistry, but I think its worth another check. EDIT: if 16.8ml is correct then I might need some help sorting out the spreadsheet haha.

Ive been using the brewfather water calculator to get this number, I'm assuming from what Mark suggested above that the calculator would be making adjustments for the Vienna and Wheat malts.

 

[mynameisrodney]

Ok so I've now put the info into Bru'n water, EZ water, and Brewersfriend, adjusted to your 11.1kg grain bill. EZ and BF both give 5.18, so close enough, but Bru'n water (which I've been using for my beers) is still giving 4.75. Dammit! I've triple checked all the tabs and cant find anything wrong. I hope I can figure this out, and if any of my recent batches have been wrong.

 

[scruffy40nil]

Ok so I've now put the info into Bru'n water, EZ water, and Brewersfriend, adjusted to your 11.1kg grain bill. EZ and BF both give 5.18, so close enough, but Bru'n water (which I've been using for my beers) is still giving 4.75. Dammit! I've triple checked all the tabs and cant find anything wrong. I hope I can figure this out, and if any of my recent batches have been wrong.

I'm not too familiar with Bru'n water as I've only use it once. I'm not all that confident in putting 100% trust in any water calculator. I'll be adding 80% of the lactic acid to my mash water and then making adjustments once I check the mash pH after 10-15mins of mashing.

 

[MHB]

Snip
Starting water is Sydney (Ryde) water and target water is Yellow Dry (under 6 SRM) water profile from beer smith.
Mash Water Additions:
Calcium Chloride (CaCl2) 1.61g
Epsom Salt (MgSO4) 3.66g
Gypsum (CaSO4) 5.39g
Lactic Acid 88% 16.8ml
Snip

In 48L I only get about 32ppm of Calcium, admittedly just a quick finger count, I don’t know how much Ca your tap water has but I like to add about 100ppm (50-100ppm is regarded as a minimum).
I doubt that’s the cause of the problem under discussion but it just stuck out as being a bit odd.
Mark

 

[scruffy40nil]

I'm only trying to reach 50ppm for this XPA.. thats working from 15ppm Sydney water

 

[MHB]

Why?
Seriously why, I'm curious, 50-100 is as above regarded as a minimum, personally I aim around 100-150 in most beers, some higher. Lots of good reasons to have more than just the bare minimum of Ca available
I would leave out the Epsom Salts and use more Ca something to taste. If you have enough Sulphate and Chloride you can always use Calcium Lactate, gives you Ca without the Cl or SO4, also when you mix Lactic and Lactate you get a very powerful buffer complex that works to my mind better than stuff like 5.2.
Mark

 

[scruffy40nil]

I'm really just playing around with this recipe as I have brewed it a few time now, my aim is for a dry xpa . So I'm using the water profile yellow dry (under 6 SRM) from Beer Smith, As this was suggest to be a good profile to work with.

 

[MHB]

Fair call, you can get quite a lot paler and dryer if that’s where you are heading. I doubt there is any connection with low Ca and pale colour, arguably more Ca could help as it aids trub formation and helps Alpha Amylase resist being denatured, a pH of 5.2 is pretty close to the optimum for Beta Amylase which will keep the beer dryer.
Not saying the recipe looks anything other than lovely,
Best Extra Pale XPA I have tasted was done with 100% UK extra pale malt, about the same colour you are aiming at, perhaps even a bit paler. Personal taste.
Mark

 

[scruffy40nil]

Thanks Mark, really do appreciate the feedback.. I might actually try the 100% UK extra pale malt...

 

[duncbrewer]

@scruffy40nil
Okay thanks for update, lots of good advice above. Still seems a lot of mash water and not much sparge.
What kind of Brewhouse efficiency do you get with these volumes.
I'm happy to go much wetter mash if you are getting good figures, I'm finding that my 20 litre mash, 6 kg of grain and 18 litres of sparge still leaves wort draining that is well over 1.020. With that I'm getting around 75% efficiency.

 

[MHB]

Might be worth starting a new thread.
Here is a table of L:G for first running yield, in efect no sparge. You can get a lot more if you sparge, properly, if you are only getting 75% I suspect you are sparging way too quickly or something like that as it isnt working very well.

If you want to pull it all apart and see where it takes you, start a new thread on efficiency.
Mark

 

[duncbrewer]

@MHB
Thanks for that, I'll start that thread later. Sparge is very fast most of the time unless lots of gummy adjuncts, recirculate normally flat out. I'll bring it all up in the thread.

 

[mynameisrodney]

Ok I've gone through the spreadsheet about 5 times now and I'm still stumped. Can somebody who uses Bru'n water take a look at this and see what I'm doing wrong? It all set up as per recipe in this thread, and Ryde water report from Sydney water.