Reducing Mash PH

[The Baron]

Hi I have been reading up on reducing the mash PH and come across a rough guide of using 9g of acid malt per kilo of grainbill or 0.25 ml of lactic acid at approx 80% ish. This would equate to 1ml of lactic per 0.1 reduction on a 4kg grainbill or 36g of acid malt. I am a amateur and only looking for a simple way of getting my mash PH there or thereabouts and by no means a expert, does this sound a good approximation as my last mash PH was 5.9 and I would like to get in the middle band of 5.2/5.6 ish. Ps I do not want to spend the time learning water composition/PH at the mo but do require to get a little nearer than I am I do find the water chemistry side too tedious and it would take away the enjoyment of the hobby but using it as a first step towards learning it at a later date if it does interest me.

 

[chthon]

The main problem is always that the mash pH is dependent upon your recipe. Blond beer has a higher pH than darker beer. Caramel malts also reduce pH, the darker they are the lower the pH. Roast malts (stouts e.g.) also can bring pH down, even in such a way that pH must be increased, e.g. by using sodium bicarbonate.

The best way to get your pH correct is to measure it, either by using strips or a pH meter.

There is also a thread on this forum where the more advanced brewers give tips if you post your recipe: "Beginners guide to water treatment".

 

[Horners]

Also not an expert but sticking in some carbonate reducing solution (CRS) does the job for me. My water is quite hard (196 ppm CaCO3) and having toyed with calculators I just use 1ml CRS per litre of liquor.

 

[The Baron]

Hi chthon I have measured the PH of the mash and the problem is that by the time I have measured the ph it is usually too late to adjust it with the modern malts which convert very quickly and also the sample has to be cooled which also takes time therefore I have been advised that it is preferable to add the lactic or acid malt prior to mashing so I m having to ballpark it depending on the grain bill type as you say darker malts and crystal change the PH differently to lighter malts but I can adjust this in my rough calculations. I am just looking for a ballpark I can use and adjust it for each brew but need a starting point on the next brew. My last brew was a Saison and the PH was 5.9 which is a little higher than I would like

 

[chrisb8]

I too wanted to treat my water without learning all the in depth chemistry and have found that the water calculator on this forum works for me. I have also recently been adding lactic acid at a rate of around 0.5ml/kg to help make sure that the mash pH is in the correct range and I have been getting consistent readings of 5.5. However this is based on my experience with my water and taking pH readings from a number of mashes to come up with what works for me. And as said above a lot depends on the grain bill as different grains have different buffering capacities and as such need treating differently.

 

[strange-steve]

If it's ballpark figures you're after then according to Braukaiser adding acid malt as 1% of the grain bill will reduce the pH by about 0.1 so if you were to brew the same recipe again you could replace some of the base malt with 3 or 4% acid malt to hit your target.

As others have said though, this is only relevant for that particular recipe. Roast malts and crystal malts will also cause a pH drop but by exactly how much is just guesswork. Targeting specific water alkalinity depending on the colour of the wort, while not 100% accurate, is a reasonably reliable method of hitting an acceptable mash pH.

 

[The Baron]

Thanks Steve I am just in the process of reading your sticky and trying to get my head around it

 

[The Baron]

Ps Steve I got my KH/Alkalinity test kit today and it says it is 7.3 dKH or 130ppm so it looks pretty good for the dark beers according to the figures in your sticky and will need only a slight adjustment there but more on the lighter beers

 

[strange-steve]

Ps Steve I got my KH/Alkalinity test kit today and it says it is 7.3 dKH or 130ppm so it looks pretty good for the dark beers according to the figures in your sticky and will need only a slight adjustment there but more on the lighter beers

Yeah that's definitely workable. If you have lactic acid then try this for your mash water over the next few brews and check the mash pH, it should be pretty good:

For a pale beer - 0.2ml/l
For an amber beer - 0.18ml/l
For a brown beer - 0.1ml/l
For a black beer - leave as is

If you have acid malt, which some people prefer, then 100g of acid malt is approximately equivalent to 3ml of 80% lactic acid.

Note also that you should probably reduce the alkalinity of your sparge water to about 20-30ppm regardless of the type of beer.

 

[The Baron]

Thanks Steve slowly getting my head around it and I have some acid malt so will try the lactic first and I think your advice looks spot on to me. Once I have cracked the lactic will try the acid Malt, many thanks for the advice Steve and will report back on my brewdays I have started to post