Water pH adjustment & dry yeast packets

[Fore]

OK, 2 different questions :)

I'm wanting to adjust my batch sparge water to pH 6 or less, using Phosphoric acid. I have a rough idea what my tap water pH is, and I have the 5.2 to 6.8 pH strips, so I can verify the result of the addition. Thing is, I have no idea how much acid to add to get in the ballpark before I measure. Is there some sort of rule or calculator for this?

And dry yeast packets. I'm under the impression that it's best to add a couple of yeast packets if you are pushing the ABV envelope on a standard brew. But if doing a Belgian for example, and if using a dry yeast made for that purpose, with high stated maximum ABV levels such as 11%, is it really necessary to add 2 packets?

 

[strange-steve]

OK, 2 different questions :)

I'm wanting to adjust my batch sparge water to pH 6 or less, using Phosphoric acid. I have a rough idea what my tap water pH is, and I have the 5.2 to 6.8 pH strips, so I can verify the result of the addition. Thing is, I have no idea how much acid to add to get in the ballpark before I measure. Is there some sort of rule or calculator for this?

And dry yeast packets. I'm under the impression that it's best to add a couple of yeast packets if you are pushing the ABV envelope on a standard brew. But if doing a Belgian for example, and if using a dry yeast made for that purpose, with high stated maximum ABV levels such as 11%, is it really necessary to add 2 packets?

The pH of your tap water is pretty much irrelevant, what you need to know is the alkalinity. Without that the only way to know how much water to add is by trial and error.

As for your second question, you should still use the same pitch rate regardless of the max abv of the yeast. Proper pitch rate is determined by the OG and the volume in order to ensure healthy fermentation.
The common preferred pitch rate calculation is 0.75 million cells per milliliter of wort per degree plato of the wort (1°P is roughly equal to 4 gravity points). Eg. If you have 20L of 1.080 wort then you need 300 billion cells. According to Fermentis their dry yeast contains >6B cells/g which means a single packet has >66B cells, so in the example above you would need 4.5 packets!
However to complicate matters further, studies have been carried out which show that the cell density is actually much higher than that, in some cases up to 18B cells/g. So some calculators use an average of 10B cells/g which I think is a good compromise.
As you can see, pitch rates can be very difficult to determine with any sort of accuracy.

 

[Fore]

pH: Yes, I might be being daft. I'm quite clued up on water adjustment to meet mash pH (I know my exact alkalinity and hit my mash pH no problem), but for some reason I thought it was a completely different calculation when dealing with only water. I'll try looking at Brun Water again without any malt addition. Thanks.

Yeast: I'm a bit confused then why yeasts sold for high ABV Belgium styles don't come in a larger packet than normal ABV beer yeasts. My next brew SG is 1.075 and 23l, so following your calcs, I need almost exactly 3 packs of 11g dry Belgian style yeast. That seems a lot, and pushes it into liquid yeast price territory. Is that right? I am slowly moving towards the idea of starters, and it might be that I need to speed up that transition.

 

[Fore]

OK, had a look at Brun Water. Thinking straight, the grain bill doesn't normally have a huge impact on the mash pH anyway, unless it's a dark or acidified. I normally treat all my water, so my sparge water, according to Brun Water, is already about 5.5 pH. Does that sound right, i.e. if you treat all your water, then even the sparge water would be well less than pH 6?

The reason why I'm looking into this is because I get what seems to me like astringency. But if the pH assessment is right, it can't be astringency can it? So I'm at a bit of a loss. All said, I am planning to try a different base grain as I have a small feeling that its that. When I brew with a different grain, Pils, it produces a much better beer.

 

[strange-steve]

pH: Yes, I might be being daft. I'm quite clued up on water adjustment to meet mash pH (I know my exact alkalinity and hit my mash pH no problem), but for some reason I thought it was a completely different calculation when dealing with only water. I'll try looking at Brun Water again without any malt addition. Thanks.

Yeast: I'm a bit confused then why yeasts sold for high ABV Belgium styles don't come in a larger packet than normal ABV beer yeasts. My next brew SG is 1.075 and 23l, so following your calcs, I need almost exactly 3 packs of 11g dry Belgian style yeast. That seems a lot, and pushes it into liquid yeast price territory. Is that right? I am slowly moving towards the idea of starters, and it might be that I need to speed up that transition.

If you go to page 2 on Brun Water it works out your sparge additions for you.

I know many, including the Brulosophy experiments, will tell you that pitch rate might not make a big difference, but imo proper yeast management is the most important aspect of brewing. For any Belgian beer I would always use a liquid yeast. The yeast phenols and esters are the main flavours in most Belgian styles so I wouldn't skimp on it.