The effect of pH on hop flavour & aroma… an experiment

pH StripsThe hop character of my beers is something I’ve tried to perfect since I started brewing. Sometimes it’s incredible, other times it’s very muted and dull. My IPA’s tend to have amazing aroma and character, but that’s easy to get when you dry hop. There are a lot of great beers out there with excellent hop character that don’t get dry hopped (think Sierra Nevada Pale Ale or Tankhouse Ale), but I can’t seem to get that definition to my hop character. Why is that?  I take it as a personal challenge to figure out, as it’s important to me. After all, this is ‘Hoptomology’ isn’t it?

I’ve recently tried ‘hop standing’, or allowing my flame out additions to steep in the pot (covered) for up to 20 minutes before whirlpooling. This technique has definitely imbibed some beautiful hop flavour, but the aroma isn’t where I’d like it to be. I’ve tried shortening that time by whirlpooling immediately after flameout, but that doesn’t seem to do it either. Don’t get me wrong, these steps do give you a certain quality, just not the one that I’m searching for here. I’ve recently built a hopback that I plan on experimenting with, using whole cone hops, but that will be a topic for another time.

There are some great podcasts on Brew Strong with Jamil Zainasheff and John Palmer about water chemistry and mineral additions. Most of the info is explaining how the different ions work in relation to brewing chemistry. The focus is usually on getting the pH in the mash in the appropriate range, which is important, I get that. What I don’t hear much about is how it affects the taste of the beer.

John Palmer did mention briefly in his interview with Brad Smith, that a pale ale type beer with a higher finishing pH will demonstrate a muddled, less defined hop character, whereas a pale ale type beer with a lower finishing pH will be perceived as brighter and crisper.

Building upon that thought, Gordon Strong has mentioned a few times that while he was at Sierra Nevada’s Beer Camp, he noticed that they adjust all of their brewing water with phosphoric acid to a pH of 5.6. Now, you can’t just take someone’s water adjustment at face value, because everyone’s water profile is different, and who knows what else they do to adjust their water. BUT, it did get me thinking about an experiment. Perhaps I could do 2 sample batches of the same beer, one with non-adjusted water, and the other with the the pH adjusted to 5.6.

pH Experiment

My Sierra Nevada Pale Ale clone recipe has always been an enjoyable one for me, so I thought it would be a good one to experiment with. From what I’ve calculated using the Bru’n Water spreadsheet, my SNPA will hit a pH of 5.6 in the mash using my existing, unaltered Toronto water. If I adjust all my brewing water to a pH of 5.6 as suggested, my mash will hit a pH of 5.3. This difference will carry on through the boil and into the finished beer, so with all else being equal, I should be able to offer a qualitative description of  the effect pH may have on not only the hop flavour and aroma, but the overall beer in general.

I’ll post some results when they’re ready for sampling.

Cheers!

 

11 Responses to The effect of pH on hop flavour & aroma… an experiment

  1. What pH was your tap water? In Toronto I’m pretty sure it would be over 7.5

    • Hey Chazz,
      Untreated, my water (Toronto as well) comes in at a pH of 7.21. But the pH of the water is an irrelevant parameter.
      It’s only the residual alkalinity and the acidity of your grain bill that play against each other to reach your mash pH, the starting water pH doesn’t factor in.

      Cheers!
      Jeff

  2. Cool experiment! I’ve read Palmer’s info on RA and still struggle with understanding it. Looking forward to hearing what pH is optimal for hop profile. I’ve been mashing at a calculated 5.50, sometimes as low as 5.45… seems to work for me although I almost always dry hop, hop forward ales.

    • It’s something that’s been on my mind for a while. I just haven’t been able to figure out how come some turn out better than others, so I thought it would be a good idea to try some experiments and take some measurements to see if I can find some correlation. If you throw a ton in, of course, it’ll be easier to get that big profile, but I always find it a personal challenge to see if I can do more with less, so to speak. I’ll let you know how it goes, just haven’t had time to write it up, soon though.
      Have you seen Palmers video on RA? Check out the ‘videos’ page on my site, I have it posted there, a great talk..
      Cheers!

  3. Jeff,

    I’m curious to try this for my pales/IPAs. Gordon Strong, says lactic acid is not as good as an option for adjusting water as H3PO4. Do you know why that is? Flavor contributions perhaps? Also, where did you source it? I can’t seem to find a local shop that carries it.

    • Hey David!
      It’s the flavour contribution for sure. Phosphoric acid is hardly noticeable because the reactions in the mash produce similar compounds.
      With too much lactic acid you’ll get the tang/sour flavours coming through, but it will still work.
      I had to order some from Northern Brewer and pick it up at a friends house when I was in Florida last year. They don’t ship to Canada.
      Be sure it’s “food grade phosphoric acid”. I found some stuff called “pH Down” which is 85% pure and is used in adjusting aquarium water for fish and animals. I was hesitant to use it at first, but gave it a shot for a couple beers, and I noticed my stomach was a little sensitive to it, so perhaps there’s something in the 15% that we shouldn’t ingest, so I’d avoid that.
      Not sure if anyone has started carrying it since I got mine, but do a search. Please let me know if you find any available in Canada!
      Cheers!

  4. Pingback: The effect of pH on hop character – The Results | Hoptomology

  5. I use around 3-4 ml of lactic acid in my mash tun. I brew around 13 gallons at a time. I haven’t noticed a sour taste, but I do notice a tingling on my tongue sometimes. I use 100% RO water so I need to get the PH down. I never got that tingling on my tongue when I used acid malt. Isn’t that bascially the same thing?

    • I think it’s basically the same thing in that the acid malt does have lactic acid sprayed on it, so that part is the same, but I think because it’s with the malt, you get a ‘softer’ contribution of acid than straight lactic acid. Don’t know if that makes sense at all, but I did read it on Weyermann’s site, not to mention, noticed the difference in my beers as well.
      Here’s the Weyermann article http://www.weyermann.de/downloads/pdf/Weyermann_TKW_Mash-pH_2010.pdf if you want to give it a read…
      Cheers!

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