Unintentional tartness - help investigate

[onpointbrewing]

Hi all - I have lurked here for the better part of a year. Decided to join and this is my first post here. I've recently gotten back into brewing after about a 10 yr hiatus. Since reentering the hobby I've brewed about 20 all grain batches. To give you an idea of my process, I brew on a Grainfather, use a ferm chamber to control temps, and I keg.

Just this weekend I took my first taste of an XPA that I brewed (it's actually the Resilience recipe to help support those impacted by the Australian wildfires, scaled down to my system and adapted for ingredients I have access to). The beer was well carbonated and tasted nice and refreshing. However, there was a rather pleasant, but unexpected tartness to the beer...almost sour. I actually really like it.

What concerns me is - this beer may have over attenuated. Here's my recipe/notes from the brew:

Water:
Adjusted my water using Bru'n Water tool. Used 7.64 gal between strike and sparge. Used a campden tab to treat water prior to heating. Targeted final values were:

• Sulfate: 99 ppm
• Chloride: 206 ppm
• Magnesium: 37 ppm

Also added 88% lactic acid for a target mash pH of 5.42. I did not measure to confirm this.

Grain Bill:

• 9.75 lb 2-row
• 1 lb Vienna
• 0.5 lb White Wheat Malt

Mash at 150F for 60. Mash out at 167F for 10 min. Boil for 60 min.

• 60 min - 0.3 oz Simcoe
• 15 min - 0.3 oz Cashmere, 2 oz Mosaic
• 10 min - 4.4g yeast nutrient, whirlfloc tab
• 5 min - 0.7 oz Cashmere

Cool to 95F using CFC and direct pitched 1 pack Omega Voss. Maintained 95F in fermenter. Vigorous fermentation within 6 hrs (typical in my experience for Voss). Dry hopped 2 days in w/ 2 oz each of Mosaic and Cascade. Fermentation was done on day 5, let temp fall to ambient. Crashed on day 8, kegged on day 11. Burst carbed at 40 psi for 24 hrs, reduced to serving pressure for 2 days prior to taking first pour.

Vital Stats:

• System efficiency is in the low to mid 70s.
• Target batch size: 5.5 gal
  • Actual: 5.25 gal in fermenter
• Target OG: 1.049
  • Actual OG: 1.052
• Target FG: 1.009 (assuming 82% attenuation, upper end of Omega's stated range)
  • Actual FG: 1.005 or 1.007*

*I use a Tilt and just take manual hydrometer readings to confirm OG/FG readings. Tilt readings confirmed my OG reading, but measured a 1.007 FG. My hydrometer (admittedly a cheap one), on a degassed (12 hrs) sample measured 1.005.

Two additional relevant factst: 1) I went to a different homebrew store for grains this day. Grain crush appeared to be finer than what I get at my LHBS. This could have thrown off my numbers due to increased efficiency. And 2) I recently took a can of my beer into my LHBS just because I talk with one of the guys there about recipes and wanted to share a recent batch he helped select the hops for. He said he'd sample at the end of the day, and I did not return for a couple weeks. When I brought it up, he didn't remember much, but said it was good. The only knock he had, was that it was tart. Now, I don't recall this beer being tart at all. I had canned this beer to empty a keg, so I do have some left in the fridge to test out myself.

I know that's a lot of info - but I wanted to provide enough detail for a proper evaluation. Really what I am wondering is what I need to do moving forward. Could this be that my lactic acid additions are reaching flavor thresholds? Is this just a LAB contamination, or do I have a bigger problem? I am meticulous about cleaning and sanitation, so I am a bit confused how this happened (although I did have my dad helping me that day and he is not a brewer). I ferment in PET carboys - do I need to clean using a special technique? Or replace?

I am also wondering if all of my beers have been tart, and maybe I am just not that sensitive to it. I have ordered a pH meter and plan to test the beer in question as well as one of the remaining cans that I shared with the guy at the LHBS. Any input to help me figure this out is much appreciated! Thanks for reading.

 

[McKnuckle]

It's not surprising to me that the high mineral levels in your water caused a low pH. I plugged in your recipe and Cl/SO4 levels into my calculator, and came up with a 5.17 predicted mash pH. If you added lactic to that, then wow, you're way below the recommended range and I'm sure it will be perceptible in flavor.

I'd suggest you back way off on the minerals in your next brew... Aim for 50-100 ppm Ca with a balance of Cl and SO4, or weighted toward one or the other, ignoring Mg for now. Add lactic acid to reach 5.4 pH, but measure it carefully. Alternately, use acid malt which is much easier to weigh out.

 

[Cavpilot2000]

Yeah, that's a lot of minerals. Especially Chloride.
Are you working off of a Ward Labs report on your water as a baseline?

 

[onpointbrewing]

I am working off of values from a Ward Labs report. There was actually really good agreement between the Ward report and the values within the water utility report.

I had read that a 2:1 Cl:SO4 ratio would lead to a soft mouthfeel. I believe it was Scott Janish's blog where he said about 200 ppm Cl and 80 ppm SO4. I've had success with this profile in bigger IPAs.

I may have something going on with my spreadsheet. Here are some screenshots that show the various inputs/outputs:

 

[OnePlate]

My first thoughts were also regarding minerals, but more precisely what your baseline water looks like, especially the hardness of the water and starting pH. I also see you're using Voss as your yeast. Although Voss is not the worst offender (with Oslo being the worst), the Nordic farmhouse yeasts produce beers with a lower final pH than most other brewing strains, so you probably have a couple layers of reasons for that tartness. Going lighter on the brewing salts and maybe adding a little bicarb as a buffer will probably help. Experiment with it, and good luck!

 

[Loud Brewing]

Get a ph meter, great piece of kit and will insure your values are correct coming from the software.

Partial infection is also a possibility, especially considering your over attenuation.

 

[McKnuckle]

I am noticing something off in the Water Profile Adjustment Calculator section that you posted. Your Desired Water Profile (top line) is "Yellow Dry," which has relatively modest mineral content (Ca 50, SO4 105, Cl 45). Scroll down a bit to Target Finished Water Adjustment, and you can see that your existing water requires certain additions and reductions in order to match this Yellow Dry profile. Again, they are modest - you need to add 14 ppm Ca, 79 SO4, and 31 Cl (and insignificant reductions in Na and Mg).

But the next line down, Actual Finished Water Adjustment, shows that your mineral additions are dramatically higher than the "Target" line numbers: 98 Ca, 25 Mg, and a whopping 192 ppm Cl. The "Mashing Water Profile" shows the results of this, and of course it's not close to the original Yellow Dry profile that you were seeking.

I really can't figure out why the mash pH prediction is relatively high with all of this, unless there's an error somewhere. But in my opinion, you should have used the recommended adjustments on the Target line, then modified only the lactic acid to hit your desired pH.

 

[onpointbrewing]

Thanks everyone for the input. I will certainly be backing off the minerals on the next batch. I have also ordered a pH meter to verify my values from the software when brewing moving forward. I'll also measure the pH of this beer and report back. Should I take the reading after letting it decarbonate?

I've been thinking about the possibility of over attenuation. The more I think about it, the less I think there was true over attenuation and more I think I just hit a higher efficiency. I tested this by adjusting efficiency values in my recipe software. For example, my original recipe posted above was at 72%, and when I adjust to 78% efficiency, the predicted OG/FG matches up with what I measured. I also found that, in fact, I had only input 78% attenuation within the recipe (midpoint of Omega's stated range), rather than the upper end 82%.

 

[onpointbrewing]

I am noticing something off in the Water Profile Adjustment Calculator section that you posted. Your Desired Water Profile (top line) is "Yellow Dry," which has relatively modest mineral content (Ca 50, SO4 105, Cl 45). Scroll down a bit to Target Finished Water Adjustment, and you can see that your existing water requires certain additions and reductions in order to match this Yellow Dry profile. Again, they are modest - you need to add 14 ppm Ca, 79 SO4, and 31 Cl (and insignificant reductions in Na and Mg).

But the next line down, Actual Finished Water Adjustment, shows that your mineral additions are dramatically higher than the "Target" line numbers: 98 Ca, 25 Mg, and a whopping 192 ppm Cl. The "Mashing Water Profile" shows the results of this, and of course it's not close to the original Yellow Dry profile that you were seeking.

I really can't figure out why the mash pH prediction is relatively high with all of this, unless there's an error somewhere. But in my opinion, you should have used the recommended adjustments on the Target line, then modified only the lactic acid to hit your desired pH.

Thanks, McKnucle - The "Target" values are just defaults and are there for reference when making calculations. Since there was not a default "Target" value that matched my desired target mineral values, I just left that at the Yellow Dry profile. Changing this "Target" profile does not change any values as far as I can tell.

I understand your point though, and plan to shoot more for a target profile around Yellow Dry for my next brew.

 

[camonick]

I’m just starting to understand the use of brewing salts and how to use the Bru’n water spreadsheet so I’m by no means an expert. Adding 3.2 grams of calcium chloride to your mash water is what’s making your numbers so high, omitting that would make the numbers a lot closer to that yellow dry profile. But if you’re brewing an IPA, why not use the profile for a pale ale as a starting point? Just my 2¢... maybe I’m misunderstanding what you’re shooting for.

 

[thehaze]

Get yourself a pH meter. I know, it sounds like a moderate expensive investment, but it will only help your future beers and brewing practices. I don't believe 100 ppm SO4 and 200 ppm Cl in the mash is too much. It sounds a lot for those adopting a more american approach to brewing liqour. I regularly use as much, if not greater amounts in most beers. Mash pH is usually around 5.4. How much Lactic acid did you add? If you added more than 2-3 ml, then your pH, would've been pushed closer to 5, but fermentation would've been normal. As pointed above, some yeast will drive poast fermentation pH lower than others. Testing the pH of the finished beer - before carbing up - will tell you what to expect in terms of tartness of lack thereof.

 

[dmtaylor]

he didn't remember much, but said it was good. The only knock he had, was that it was tart. Now, I don't recall this beer being tart at all. I had canned this beer to empty a keg, so I do have some left in the fridge to test out myself.

^^^^ Here's your real problem. Ask yourself again, is he wrong? I think it's very possible, even probable.

 

[onpointbrewing]

Get yourself a pH meter. I know, it sounds like a moderate expensive investment, but it will only help your future beers and brewing practices. I don't believe 100 ppm SO4 and 200 ppm Cl in the mash is too much. It sounds a lot for those adopting a more american approach to brewing liqour. I regularly use as much, if not greater amounts in most beers. Mash pH is usually around 5.4. How much Lactic acid did you add? If you added more than 2-3 ml, then your pH, would've been pushed closer to 5, but fermentation would've been normal. As pointed above, some yeast will drive poast fermentation pH lower than others. Testing the pH of the finished beer - before carbing up - will tell you what to expect in terms of tartness of lack thereof.

Thanks, haze - I appreciate the input. I just received my pH meter, and am looking forward to using it. I actually saved a small sample of my wort post-boil leftover from my OG reading for an IPA that I brewed earlier this week. I shot for the "Yellow Dry" profile that you can see in the images above (in short 100 ppm sulfate; 50 ppm chloride). I just measured the pH and it was 5.3, which from my brief reading on the subject, is about right. Interestingly, I added 3.8 mL and 1.6 mL 88% lactic acid to the strike and sparge water, respectively.

 

[onpointbrewing]

I got my pH meter yesterday and had some fun taking measurements. In addition to the measurements I attempted to assess sourness/tartness by measuring titratable acidity (TA). I followed the nice instructions on the Milk the Funk wiki for this part, and it was very simple. Here are my notes:

I started by de-carbing a sample of a) the beer that is the subject of this thread (an XPA), b) the beer that I was told was tart at the homebrew shop (Funky Monkey IPA), and c) a Stone Delicious IPA just for fun. I ran each through a coffee filter into a sample container, then covered with aluminum foil and let them sit for 24 hours before taking measurements.

I began by taking the pH of each sample (at room temp):

Then titrated a measured sample of each with a 0.2M NaOH solution and calculated titratable acidity in lactic acid equivalents:

Here are my results:

• Stone Delicious IPA: pH= 4.61, TA= 1.7 g/L
• Funky Monkey IPA: pH= 4.67, TA= 2.57 g/L
• XPA: pH= 4.52, TA= 2.76 g/L

I also tasted each beer after I poured off the necessary 50 mL for sampling (the fun part), and didn't notice any tartness in either the Stone or my IPA. I did still notice a bit of what I perceived as a bright tartness with the XPA.

It appears that the pH of all the beer measured is within a tight range and this wouldn't lead me to believe my beers are tart from these measurements alone. There is more of a difference in the TA values and there does seem to be a trend in both the pH and TA here. I wasn't able to find any TA measurements of non-sour commercial beers, so I don't know if my single data point is representative or not, or how big of a range exists. I did find an article on Craft Beer & Brewing that indicated sour beers ranged from .3-.75% (or 3-7.5 g/L). I also found some slides that presented data from a White Labs study of perception of sourness in beers. The results indicated that TA was a better predictor of the panel members' sourness score than pH. The lowest TA of "sour" beers they tested was 4.4 (range 4.4-18.7) and the lowest pH was 3.35 (range 3.35-3.67).

All this is interesting, but I'm not sure it answers my initial question. I would certainly like to test more commercial beers (and more of my own) going forward. I will note that Omega Voss was used to ferment both of my beers that were tested. Given that I perceive tartness in my XPA, but not my IPA and the values are very close, I wonder if I am misidentifying the "off flavor" (I use quotes because this beer is delicious, and it's going fast). Anyway...it was fun digging into it!

 

[onpointbrewing]

^^^^ Here's your real problem. Ask yourself again, is he wrong? I think it's very possible, even probable.

After tasting a can of it, I think you’re correct. I was searching for a hint of sour, and...nothing.

 

[Dgallo]

IMO and in my experience, elevated mg levels, 20+ can cause harshness and a slight tang(tartness). I used to adjust so4 exclusively with mgso4 (epsom salt). With my base and adjustments my mg level would be 23-27 based on the beer and my beers would have tartness. I’ve since stopped and adjust so4/cL with gypsum and build additional cL with cacl and NaCl which keeps my mg under 12 and my beers are no longer tart.

 

[onpointbrewing]

IMO and in my experience, elevated mg levels, 20+ can cause harshness and a slight tang(tartness). I used to adjust so4 exclusively with mgso4 (epsom salt). With my base and adjustments my mg level would be 23-27 based on the beer and my beers would have tartness. I’ve since stopped and adjust so4/cL with gypsum and body the flavor with cacl and NaCl which keeps my mg under 12 and my beers are no longer tart.

That’s really interesting you bring that up. As I was looking back at my mineral additions, I noted a difference between the two of my beers - MgSO4. I hadn’t used it before I read something about getting Mg levels above 30 ppm for NEIPAs. I guess the NEIPA turned out nicely and I just assumed that would be a fine mineral addition for other beers. The XPA was the next brew.

Your description seems to line up with what I’m experiencing, and seems like the most likely explanation. Just curious, because I believe I have seen your posts on NEIPA threads...do you add any Mg to NEIPAs, or was I misinformed? Planning on brewing one next week.

 

[Dgallo]

That’s really interesting you bring that up. As I was looking back at my mineral additions, I noted a difference between the two of my beers - MgSO4. I hadn’t used it before I read something about getting Mg levels above 30 ppm for NEIPAs. I guess the NEIPA turned out nicely and I just assumed that would be a fine mineral addition for other beers. The XPA was the next brew.

Your description seems to line up with what I’m experiencing, and seems like the most likely explanation. Just curious, because I believe I have seen your posts on NEIPA threads...do you add any Mg to NEIPAs, or was I misinformed? Planning on brewing one next week.

Based on my ward lab report my tap water contains 9 ppm mg. I no longer add any additional mg. In the NEIPA thread many talk about cl/so4 ratio. If ppl are adjusting the so4 using epsom salt (mgso4) they will have elevated mg ppms. So if you looked at someone’s water profile who does, then it’s very possible you saw ppms around 20-30. I would completely advise against it. Use gypsum it will raise your for so4 and to a lower extend Cl, without adding any mg

 

[dmtaylor]

Magnesium doesn't taste particularly tart to me. It is sharply bitter and metallic and tastes absolutely horrible in general. So I don't use it. But I don't think that's the real problem here.

 

[onpointbrewing]

Magnesium doesn't taste particularly tart to me. It is sharply bitter and metallic and tastes absolutely horrible in general. So I don't use it. But I don't think that's the real problem here.

The way you worded your post makes me think you have a theory as to the cause....and now I'm curious.

 

[onpointbrewing]

Based on my ward lab report my tap water contains 9 ppm mg. I no longer add any additional mg. In the NEIPA thread many talk about cl/so4 ratio. If ppl are adjusting the so4 using epsom salt (mgso4) they will have elevated mg ppms. So if you looked at someone’s water profile who does, then it’s very possible you saw ppms around 20-30. I would completely advise against it. Use gypsum it will raise your for so4 and to a lower extend Cl, without adding any mg

Ok thanks. I'll leave that out going forward.

 

[dmtaylor]

The way you worded your post makes me think you have a theory as to the cause....and now I'm curious.

See previous posts from both you and me. I don’t believe the beer is actually tart at all. We are all just wastin’ time here.

 

[onpointbrewing]

See previous posts from both you and me. I don’t believe the beer is actually tart at all. We are all just wastin’ time here.

The more I drink it, the more I think you're correct... I tend to be overly analytical and critical of my own beers. However, I do think there is merit to the idea that Mg is causing some sharpness and I am misinterpreting it as tartness. I look forward to tasting the next beer in the pipeline that has no added Mg and comparing.