How much acidulated malt to use

[Keruso]

Tesco ashbeck says PH is 6.7, I’m after a mash PH of 5.4, mash volume is 24 liters sparge is 9 liters. Please can you let me know how much acidulated malt to add to the mash to reduce the PH, and how you work out how much you need thank you.

 

[Brew_DD2]

Tesco ashbeck says PH is 6.7, I’m after a mash PH of 5.4, mash volume is 24 liters sparge is 9 liters. Please can you let me know how much acidulated malt to add to the mash to reduce the PH, and how you work out how much you need thank you.

It depends on the make-up of the grist and the composition of the water. pH of the water won't give you the information you need.

 

[The Baron]

It is a bit of trial and error and variable to the recipe as DD2 has said but I use around 170g of Acid malt for 20ltrs and then I use lactic acid for the sparge of approx 7 ltrs of 2ml.
I hope this will give you a starting point.
Ps I usually get circa PH 5.4 ish

 

[Keruso]

It depends on the make-up of the grist and the composition of the water. pH of the water won't give you the information you need.

Hi, I’m using a recipe builder, I’ve added my grist and all the other ingredients, plus the target water chemistry I’m aiming for, and the source water chemistry, in this case Tesco Ashbeck. The recipe builder says add 0.46ml of lactic acid, but I don’t have that, only acidulated malt, hence I’m trying to work out what the equivalent acidulated malt is. Thanks

It depends on the make-up of the grist and the composition of the water. pH of the water won't give you the information you need.

 

[Keruso]

It is a bit of trial and error and variable to the recipe as DD2 has said but I use around 170g of Acid malt for 20ltrs and then I use lactic acid for the sparge of approx 7 ltrs of 2ml.
I hope this will give you a starting point.
Ps I usually get circa PH 5.4 ish

Thanks that’s what my calculations are taking me towards, I’ve never adjusted for PH before, we live and learn

 

[Keruso]

It is a bit of trial and error and variable to the recipe as DD2 has said but I use around 170g of Acid malt for 20ltrs and then I use lactic acid for the sparge of approx 7 ltrs of 2ml.
I hope this will give you a starting point.
Ps I usually get circa PH 5.4 ish

Hi, maybe a silly question, I know you can’t add acidulated malt to the sparge, but why not just use lactic acid in the mash and sparge? Why use acidulated malt in the mash ?

 

[Benfleet Brewery]

Hi, maybe a silly question, I know you can’t add acidulated malt to the sparge, but why not just use lactic acid in the mash and sparge? Why use acidulated malt in the mash ?

Good question. I use lactic acid in both, just because I have the lactic acid.

 

[The Baron]

You can use either it is entirely upto you
A couple of lifts from tinterweb
They provide that depth and flavor (Grain that is). This can't be said of refined lactic acid or cultures made from a pure lacto strain. They have a 'single note' flavor that I find unsatisfactory. Because of this, I suggest that acidulated malt would add more flavor to a beer.

Acidulated malt is ~2% lactic acid by weight, and 88% lactic acid has a density of 1.21 g/mL, so for every pound of acid malt you'd be adding 8.5 mL of acid.
Whether this equates I do not know?

 

[Keruso]

All, thanks for your help. I'm going to measure my mash ph next brew to see what is actually is. I can then make a prediction of how much acidulated malt or lactic acid to use. ChatGPT said this:-
You can use the following formula to calculate how much lactic acid to add:

Amount of Lactic Acid (ml) = (Mash Volume in Liters or Gallons) × (Current pH - Target pH) × (0.1 / Lactic Acid Concentration)

In this formula:

• 0.1 is a factor that helps convert the units of pH to a more usable scale for the calculation.
• Lactic Acid Concentration should be in decimal form (e.g., 88% = 0.88).
• So as a guide to go from a mash ph of 5.8 to 5.2 means adding 1.65ml of lactic acid.

 

[JockyBrewer]

Acidulated malt is just malt that has been sprayed with lactic acid, or has had lactobacillus cultivated on it to produce lactic acid. It's the German's way around their archaic brewing laws, and anyone else in the world can just add lactic acid to get the same effect.

Acid additions aren't there to add flavour, they're there to reduce the pH of the mash. In fact you really don't want them adding flavour - too much lactic acid makes your beer taste tangy.

To properly calculate how much acid to use depends upon you knowing the level of bicarbonate or alkalinity in the water, and what the grist is made up of. It's a sizeable subject that has been well distilled down by @strange-steve here: Beginners Guide to Water Treatment (plus links to more advanced water treatment in post #1)

The formula ChatGPT has given you looks like made up rubbish. For one thing it'll give you the same amount of acid to add whether you're using 5 gallons or 5 litres of water. Ignoring that obvious error it takes no account of the buffering power in the water, which is what really resists pH change.

 

[Keruso]

Acidulated malt is just malt that has been sprayed with lactic acid, or has had lactobacillus cultivated on it to produce lactic acid. It's the German's way around their archaic brewing laws, and anyone else in the world can just add lactic acid to get the same effect.

Acid additions aren't there to add flavour, they're there to reduce the pH of the mash. In fact you really don't want them adding flavour - too much lactic acid makes your beer taste tangy.

To properly calculate how much acid to use depends upon you knowing the level of bicarbonate or alkalinity in the water, and what the grist is made up of. It's a sizeable subject that has been well distilled down by @strange-steve here: Beginners Guide to Water Treatment (plus links to more advanced water treatment in post #1)

The formula ChatGPT has given you looks like made up rubbish. For one thing it'll give you the same amount of acid to add whether you're using 5 gallons or 5 litres of water. Ignoring that obvious error it takes no account of the buffering power in the water, which is what really resists pH change.

I have been using a salts calculator for ages but never thought to test or adjust mash PH, I use either RO or Tesco Ashbeck, input my starting and target salts into the calculator based on the style of beer I’m making and then add whatever the calculator suggests. I was looking for and still haven’t found a guide to how much lactic acid to add to reduce mash ph. I downloaded EZ-water-calculator today, input my grain bill and it estimated I need to add 2ml of lactic acid into 24L of wort to reduce PH from estimated 5.71 to 5.6, or use 100g of acidulated malt. Does this sound correct from your experience?

 

[JockyBrewer]

I couldn’t say, as I don’t tend to use lactic or check the starting pH of liquor.

Ez-water should give you a decent estimate though, and then after that it will be important to measure the pH and adjust the amount you add next time you brew the same recipe.

 

[Keruso]

I couldn’t say, as I don’t tend to use lactic or check the starting pH of liquor.

Ez-water should give you a decent estimate though, and then after that it will be important to measure the pH and adjust the amount you add next time you brew the same recipe.

Yep so measure ph and adjust if necessary cheers