The effect of pH on hop character – The Results

pH experimentThere’s been a lot of interest in the results of my experiment to find out the effect that pH has on hop character. I guess it’s something that’s been on some of your minds. Hopefully I can shed some light on what I’ve discovered.

I have to say, after kegging these two batches and carbonating them for a few days, I didn’t really notice much of a difference. But after letting them sit for another 10 days or so, the differences became obvious.

Here are the pH measurements I recorded during the process for reference:
High pH beer – Mash pH – 5.6 / Post Boil pH – 5.5 / Post Ferment pH – 3.98
Low pH beer – Mash pH – 5.3 / Post Boil pH – 5.25 / Post Ferment pH – 3.83
* All measurements were taken at room temperature.
 

Aroma

  • Low pH -
    • clearly defined Cascade character with some spicy notes from the 30 minute perle addition
    • light, balanced maltiness, very clean
    • light crystal malt aroma
  • High pH -
    • muddled hop character, no definition
    • slightly bready
    • low fusel alcohol character

Appearance

This is what surprised me the most. After leaving them for about 10 days, I pulled a pint from the low pH batch and BAM! An extremely clear pale ale. I’m not really sure of why that would happen, or the chemistry behind it, but there it was.Clarity

  • Low pH -
    • decidedly clearer
  • High pH -
    • as you can see from the picture, a haze remains

Flavour

  • Low pH -
    • crisp tasting with a defined bitterness
    • clear definition between hop flavour, malt and bitterness
  • High pH -
    • confused hop character
    • no definition between bitterness and aroma
    • malt character is flat

Conclusion

The beer with the lower pH was clearly a much more enjoyable beer. The flavours are more focused and there is a certain crispness to it. This would be an example to me of the difference between a “good” beer, and a “great” beer.

But hey, don’t just take my word for it, try it yourself!

10 Responses to The effect of pH on hop character – The Results

  1. how much acid malt did you use? any calcium chloride?

    • Hi Ian,
      I didn’t use any acid malt or CaCl. I only used 10% Phosphoric acid to bring all my brewing water to a pH of 5.6.
      That way it would give me a good baseline. Going forward I’ll start to play with salt additions, in particular the Sulphate/Chloride ratio.
      Cheers!

  2. Thanks for the information.
    I just did a brew on the weekend adjusting the ph of my sparge water. I used 3 oz acid malt as part of my grain bill (mash ph 5.19) 152F
    I didn’t realize that ph changes with temperture a lot more than I thought. I made my ph adjustments at 177 F (19L filtered tap water +2.25ml 75% phosphoric acid=5.3ph) I drained off a cup of the adjusted water & tested it later at room temp to find that the ph was back up to 6.8. Looking forward to drinking this brew.

    • Hey Rob,
      Ya, it seems like the world of pH is a whole other thing. I usually do all my adjustments and measurements at room temp, just to keep things consistent.
      For a while I was only adjusting my mash pH, but I’m trying to figure out if adjusting all the brewing water makes a difference as I imagine the flavour aspect has a lot to do with the pH of the finished beer in particular. Hope that brew turns out good! Let me know if you find out anything interesting!
      Cheers,
      Jeff

  3. What temperature where these readings taken at? 5.6 vs 5.3 mash pH @ Mash temp (ie 150′ish) or room temperature (mash samples allowed to cool)?

  4. I don’t have a PH meter, but adjusted my mash with EZY water calculator. It said my mash was 5.5. I have a permanent haze in my Blonde Ale even after an addition of Gelatin for a week. I use 100% RO water with salts additions. I can adjust it with more acid malt to a suggested mash PH of 5.3. Trial and error at this point, but I will buy a PH meter if it is really needed. My beer has always been very clear after an addition of Gelatin. Not this time though. The taste is fine and it fermented from 1.058 to 1.011.

    • Hey Chris,
      I find the Bru’n Water spreadsheet to be pretty accurate for 90% of the styles I’ve tried. (For a long time I measured with my pH & found the numbers were close enough) I would guess EZ Water would be good enough to go with without the use of a pH meter, unless you really want to get into it more.
      Have you done blonde beers before that have cleared properly? Remember, it’s not just about the mash pH. In this experiment I adjusted all the brewing water (mash,mashout & sparge). If you only adjust the mash water you will get a different pH overall and therefore different results…

  5. I’ve just kegged an APA which I’d adjusted to within -50RA as per Palmer’s recommendation. This meant the mash pH was higher than I normally like, 5.6 vs 5.45-5.50 (room temp), not sure what the resulting post ferm pH was…guess what… cloudy and muddled.

    My typical 5.45 pH adjustment would have the RA at almost -330 and my beers are almost always enjoyable. I think RA might have it’s purpose, for what I am not quite sure but I’ll be returning to my previous water/mash adjustments.

    • Interesting. Before this experiment, I had no idea that the pH had an effect on clarity or hop character, but it makes sense as pH affects the entire brewing process.
      It’s a tricky subject. Sometimes I think, if it’s working, just leave it alone, but I somehow can’t seem to follow my own advice! haha

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