Results 1 to 11 of 11

Thread: over attenuation/dry beers

  1. #1
    Join Date
    Aug 2017
    Location
    Japan
    Posts
    20

    over attenuation/dry beers

    I don’t know what’s going on because all my beers are ending super dry and the yeast is over attenuating. Usually the attenuation is about 85-88%. I’ve seen a few other posts here and they usually end with people asking for more detailed numbers so here’s what I got. Any help woud be much appreciated. Thanks!

    We’ve done 11 batches so far, every single one of them ended up finishing at around 1.6-2 plato and tasted dry.

    At the beginning we mashed for 40 minutes before starting the sparge, now we do 30 minutes.

    Usually the mash is about 68 degrees Celsius (154 F). We test the temp by using the gauge that’s built in and also by collecting the recirculated wort. The most recent mash was 71c (160f)

    The sparge takes about 40 minutes and the gauge says 78c (172f) temp and the thermometer is placed on the bottom half of the MT.

    I turn on the steam on the BK about 20 minutes into the sparge and it starts boiling pretty shortly after its full.

    We transfer to the FV using o2, not compressed air. At the beginning we were using 5 LPM but now we are using 2 LPM and it takes about 30 minutes to fill the FV.

    On about 700L (184 gallons) we’ve used 500g S-04, 5 liters Imperial Juice, and 5 liters of Omega Hornindal kviek.

    Fermentation temp is 19c (66f), except for the kviek, where it was 33c (91f).

    The pH is usually 5.3-5.4 in the mash.

    Should I just add the word "brut" to everything and call it a day?

    Thanks!

  2. #2
    Join Date
    Apr 2015
    Location
    Lakewood, CO
    Posts
    60
    Assuming your temp probe is accurate, it seems weird that such a high mash temp would still lead to over-attenuated beer. Don't know if your tun has a rake; it's possible that the mash isn't getting mixed well, and it's stratifying, with cooler areas away from the temp probe. You also didn't mention grist, but I assume at least one of those beers had something to add body, like dextrin malt. If not, you could try more crystal/dextrin/unmalted grains. I've also added lactose to provide body post-fermentation, since it doesn't ferment, but that's an ingredient that can affect drinkers, so I don't do that very often. And there's always decoction, if you're a masochist.

  3. #3
    Join Date
    Nov 2014
    Location
    Austin TX
    Posts
    1
    How long do you Vorlauf for? The probe in our mash tun is off by 4 degrees but too low not too high. How long does it take to hit terminal? Are you certain the fermenter probes are correct?

  4. #4
    Join Date
    Jan 2018
    Location
    San Jose
    Posts
    20
    I have a "wild" Hornindal culture, so I'm not sure how it compares to a lab culture, but I see 90% attenuation with it. I suspect that it may be diastatic, but I haven't tested it yet. We usually include a fairly high percentage of wheat in the beers that we make with it, so even though the beer finishes super dry, it still has good mouthfeel. We just did an 8%ABV hazy IPA with it that finished at 1.5P and it's drinking real nice.

  5. #5
    Join Date
    Aug 2017
    Location
    Japan
    Posts
    20
    Quote Originally Posted by spetrovits View Post
    Assuming your temp probe is accurate, it seems weird that such a high mash temp would still lead to over-attenuated beer. Don't know if your tun has a rake; it's possible that the mash isn't getting mixed well, and it's stratifying, with cooler areas away from the temp probe. You also didn't mention grist, but I assume at least one of those beers had something to add body, like dextrin malt. If not, you could try more crystal/dextrin/unmalted grains. I've also added lactose to provide body post-fermentation, since it doesn't ferment, but that's an ingredient that can affect drinkers, so I don't do that very often. And there's always decoction, if you're a masochist.
    I just calibrated my probes again yesterday and they seemed all accurate. We had a rake but I took it out, when we had it the beers were even drier than they are now. And yeah we have some dextrins, here's the grain bills of a few recent beers..

    52-two row, 24-Maris otter, 16-oats, 5-wheat, 7-honey malt

    63-Pilsen malt, 27-MO, 10-carapils

    55-M.O., 44-Pils, 7-crystal, 5-carapils

    67-two row, 11-wheat, 9-chit, 5-carapils, 4-spelt, 4-crystal

    Our brewery is in the middle of farms (literally, on three sides of us there are orange groves within 100 feet) so maybe there's a contamination getting in? I brew in a country where I don't speak the language and so I rely on someone else to tell me the suppliers instructions on how to mix the chemicals and that person I rely on is sometimes not the most reliable when it comes to that stuff

    Thanks!
    Last edited by Nomo; 09-11-2019 at 06:22 PM.

  6. #6
    Join Date
    Aug 2017
    Location
    Japan
    Posts
    20
    Quote Originally Posted by Arusselltx View Post
    How long do you Vorlauf for? The probe in our mash tun is off by 4 degrees but too low not too high. How long does it take to hit terminal? Are you certain the fermenter probes are correct?
    The vorlauf changes. At the beginning we did it for about 5 minutes at the end of the mash but now we just recirculate very slowly through most of the mash so by the time we start the sparge it's good to go.

    I just calibrated our probes and they all seemed to be correct.

    We hit terminal about 2-3 days after pitching but then sometimes it slowly creeps down a tiny bit more.

    The FV probes are correct but I think there may be a difference in them from the bottom to top of the FV. They are located right above the probe and we only have one glycol entrance point. I feel like I've read before that with our layout (cheap Chinese equipment) the cold will settle a lot more and there's a good amount of stratification. Our samples are always about 20c (68f) and we don't get any fusels or off flavors that would make me think it's fermenting too hot. Would fermenting too hot make that big of a difference in drying? Many of our beers are planned to end 4.8P and the actually end at 1.5P

    Thanks!

  7. #7
    Join Date
    Aug 2017
    Location
    Japan
    Posts
    20
    Quote Originally Posted by esbq View Post
    I have a "wild" Hornindal culture, so I'm not sure how it compares to a lab culture, but I see 90% attenuation with it. I suspect that it may be diastatic, but I haven't tested it yet. We usually include a fairly high percentage of wheat in the beers that we make with it, so even though the beer finishes super dry, it still has good mouthfeel. We just did an 8%ABV hazy IPA with it that finished at 1.5P and it's drinking real nice.
    Yeah I figured the Hornindal would attenuate more, on that beer we put 9.2% chit malt, 8.4% wheat, 5.4% carapils, 5.4% spelt, and 3.8% c-35 (and the other 67% was 2-row)

    But all of our beers have been ending super low, even the s-04 and Imperial Juice beers.

    Thanks!

  8. #8
    Join Date
    Oct 2013
    Location
    Stuart, FL
    Posts
    455
    Quote Originally Posted by Nomo View Post
    We hit terminal about 2-3 days after pitching but then sometimes it slowly creeps down a tiny bit more.

    Would fermenting too hot make that big of a difference in drying? Many of our beers are planned to end 4.8P and the actually end at 1.5P

    Thanks!
    I have some follow up questions. How long are you running 2 lpm of O2? What is the quantity of yeast produced? Is the fermentation curve smooth or do you see abrupt drops or stalls?

    Presuming you are pitching a 500gm pitch of US-05 into 700 liters at say 12*P, you are at the high-ish end of rule-of-thumb pitch rates (not really an issue in most cases). I am fairly certain Fermentis says aeration of wort is not necessary for their dry yeast. If you are adding 2-5 lpm of O2 to the wort, you could be driving excessive yeast production, thereby increasing the potential for over-attenuation. The length of time you run O2 would directly impact this.

    Symptoms would be what you describe, over-attenuation, but would usually include excessive yeast in the cone as well. The short primary time is another indicator that this could be the situation. More yeast cells would induce a faster fermentation (relatively), regardless of temperature. Yes, higher temperatures can lead to higher attenuation as well, but as you mention, fusel production is usually evident.

    Abrupt drops or stalls can indicate things such as diastatic strains and certain bacteria. You can also plate & incubate to verify contamination status.

  9. #9
    Join Date
    Apr 2017
    Location
    New Orleans, LA, USA
    Posts
    4

    Forced Fermentation and Wort Stability Test

    Nomo, have you tried conducting wort stability tests and forced fermentation tests? The wort stability test will tell you if you have a contaminant (without identification) and the forced fermentation can give you an idea of what terminal gravity will look like.

    Wort Stability Protocol from BSI: https://www.brewingscience.com/wp-co...-Blindfold.pdf

    Forced Fermentation Test from White Labs: https://www.whitelabs.com/beer/lab-m...d-fermentation

    Feel free to reach out to me if you have more questions.

    _
    Jeremy King, Brewery Design Consultant, Experienced Commercial Brewer
    Craft Kettle Brewing Equipment
    New Orleans, LA
    jeremy.king@craftkettle.com
    o 855.953.8853 | d 504.930.4462 | c 763.528.1352
    _
    Jeremy King, Brewery Design Consultant, Experienced Commercial Brewer
    Craft Kettle Brewing Equipment
    New Orleans, LA
    jeremy.king@craftkettle.com
    o 855.953.8853 | d 504.930.4462 | c 763.528.1352

  10. #10
    Join Date
    Aug 2017
    Location
    Japan
    Posts
    20
    Quote Originally Posted by UnFermentable View Post
    I have some follow up questions. How long are you running 2 lpm of O2? What is the quantity of yeast produced? Is the fermentation curve smooth or do you see abrupt drops or stalls?

    Presuming you are pitching a 500gm pitch of US-05 into 700 liters at say 12*P, you are at the high-ish end of rule-of-thumb pitch rates (not really an issue in most cases). I am fairly certain Fermentis says aeration of wort is not necessary for their dry yeast. If you are adding 2-5 lpm of O2 to the wort, you could be driving excessive yeast production, thereby increasing the potential for over-attenuation. The length of time you run O2 would directly impact this.

    Symptoms would be what you describe, over-attenuation, but would usually include excessive yeast in the cone as well. The short primary time is another indicator that this could be the situation. More yeast cells would induce a faster fermentation (relatively), regardless of temperature. Yes, higher temperatures can lead to higher attenuation as well, but as you mention, fusel production is usually evident.

    Abrupt drops or stalls can indicate things such as diastatic strains and certain bacteria. You can also plate & incubate to verify contamination status.

    I'm running the O2 for about 20-30 minutes, the time it takes to transfer the wort to the FV. That's interesting about the fermentis, I didn't know that and that's good to know for the future (although we've moved away from them to liquid yeast now) The first 4 beers we made we used S-04 and got an average of 87.85 attenuation with a TG of 1.0054. Then we have 4 beers used with Imperial Juice (which says to add 50% more oxygen than you would with other liquid yeast) and we got an average of 87.25 attenuation with a TG of 1.0052 (Our OGs were pretty low at the beginning as we were trying to figure our system out and we try to make lower abv beer for Japan)

    There was one outlying beer with a TG of 1.013, and attenuation of 76% (which is what we predicted) and the more that I think about it I think we used a different sani on the tanks for that one.

    There's no yeast above the racking arm and I don't really know how much a normal amount would be but it doesn't seem excessive. At most we would be getting 20L of yeast/trub on the 700L in the FV.

    A few examples of how fermentation usually goes are...

    4-29 (S-04) pitched at 11.6, 4-30 it was at 4.21, 5-1 it was at 1.06

    5-1 (S-04) pitched at 10.3. 5-2 it was at 9.65, 5-3 it was 1.84 for three days. when we bottled it had lowered more to 1.35.

    5-4 (S-04) pitched at 14, 5-5 it was at 10, 5-6 at night it was at 1.5

    5-27 (Juice) pitched at 13.3, 5-20 it was at 8, 5-21 it was at 4.03, 5-22 it was at 3.25. (This is the one that ended up ok and I think [50% sure] we used diff sanitizer on)

    8-31 (Juice) pitched in the afternoon at 15.3, 9-1 it was at 3.84, 9-2 it was at 2.8, 9-7 it was 2.8. today it was 1.5.

    We haven't had any stalls, it seems to drop quickly and then slowly drop after that. I keep asking the guy that does the ordering to get me stuff to test the yeast but he hasn't gotten it yet so maybe this will get him more motivated to do so. (We do fresh pitches on all our batches, we will start harvesting soon but it's a bit of a long story why we haven't yet. Brewing in a country you don't speak the language can be interesting sometimes haha)

    Thanks for your help!

  11. #11
    Join Date
    Aug 2017
    Location
    Japan
    Posts
    20
    Quote Originally Posted by Jeremy N King View Post
    Nomo, have you tried conducting wort stability tests and forced fermentation tests? The wort stability test will tell you if you have a contaminant (without identification) and the forced fermentation can give you an idea of what terminal gravity will look like.

    Wort Stability Protocol from BSI: https://www.brewingscience.com/wp-co...-Blindfold.pdf

    Forced Fermentation Test from White Labs: https://www.whitelabs.com/beer/lab-m...d-fermentation

    Feel free to reach out to me if you have more questions.

    _
    Jeremy King, Brewery Design Consultant, Experienced Commercial Brewer
    Craft Kettle Brewing Equipment
    New Orleans, LA
    jeremy.king@craftkettle.com
    o 855.953.8853 | d 504.930.4462 | c 763.528.1352

    Thanks for the links, I will definitely look at them and see what kinds of tests I can do and then do pretty much everything I can, cheers!

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •