Ben Matthews
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- Jun 10, 2020
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Hey peeps. My first post here so Hi! I'm looking for some advice on my current batch which is my 7th all grain brew.
It's a Belgian Blonde Ale started a couple weeks or so back. It's basically
3kg pilsner malt
100g wheat
100g munich
350g sugar
25g hallertau at 60 mins.
5g saaz at 5 mins
(Bristish so sorry for all the metric measurements)
Used a new yeast for the batch; WYyeast 3522 Belgian Ardennes, and for the first time some wyeast nutrient blend. I made a couple consecutive starters with the smack pack to try and get a good pitch going. Both of these starters went crazy and did end up blowing off what i thought was a considerable amount of yeast to the point where on pitching I was unsure how much yeast I was actually pitching.
Mash and boil went really well hit target og of 1.067
Pitched at 17 degrees C (63 F) and temperature was held until after high krausen and then slowly increased up to 20C (68F) over a week and 22C (72F) by end of second week. Now at 23C. Fermentation took off quick. Yeast went bonkers and nearly blew the lid off. Managed to contain it with a few blow off tube changes. A little seeped from the plastic lid in one spot. Smelled amazing; yeasty and fruity as you'd expect from a Belgian yeast. Then as the Krausen dropped down a bit the smell changed. I couldn't put my finger on it but it was maybe a little peanut buttery. This increased and near the week and a half to two week mark it started smelling like peanut butter mixed with urea. Quite weird and rank.
I assumed it had got infected so took a sample. The sample smelled and tasted pretty normal. Quite darn nice taste infact and my gravity was at 1.017 so nearly there but going to leave another week and see if it goes lower. Lids been back on and a small amount of airlock activity since and more of the urea smell. The urea smell is pretty rank and I've never encountered this before. Every time my fermentation chamber is opened its not nice. I thought this will maybe condition out. I'm currently at about 2 and a half weeks into fermentation.
I did however find a couple things about urea that it is produced by yeasts and is a intermediate in the production of a known carcinogenic substance called Ethyl Carbomate. This is found in pretty much all fermented food and beverages in varying quantities. It sounds like it has no acute effect on human health but is a pretty bad carcinogen so I'm worried that even if this smell disappears during conditioning it maybe that because I'm getting a lot of urea smell there may well be a **** ton of this compound in the beer?
https://academic.oup.com/femsyr/article/17/7/fox072/4411803
https://en.wikipedia.org/wiki/Ethyl_carbamate
Has anyone ever encountered a urea smell from fermentation? The only things done different this batch are the new yeast variety and the use of the Wyeast nutrient blend (Which may actually contain urea)?
Could I have an infection?
Should I risk it or just ditch it? I was super excited about this brew as I've heard the yeast is awesome and was my first brew where everything in the process went spot on. Frustrating.
Thanks in advance peeps
Ben
Thanks peeps.
It's a Belgian Blonde Ale started a couple weeks or so back. It's basically
3kg pilsner malt
100g wheat
100g munich
350g sugar
25g hallertau at 60 mins.
5g saaz at 5 mins
(Bristish so sorry for all the metric measurements)
Used a new yeast for the batch; WYyeast 3522 Belgian Ardennes, and for the first time some wyeast nutrient blend. I made a couple consecutive starters with the smack pack to try and get a good pitch going. Both of these starters went crazy and did end up blowing off what i thought was a considerable amount of yeast to the point where on pitching I was unsure how much yeast I was actually pitching.
Mash and boil went really well hit target og of 1.067
Pitched at 17 degrees C (63 F) and temperature was held until after high krausen and then slowly increased up to 20C (68F) over a week and 22C (72F) by end of second week. Now at 23C. Fermentation took off quick. Yeast went bonkers and nearly blew the lid off. Managed to contain it with a few blow off tube changes. A little seeped from the plastic lid in one spot. Smelled amazing; yeasty and fruity as you'd expect from a Belgian yeast. Then as the Krausen dropped down a bit the smell changed. I couldn't put my finger on it but it was maybe a little peanut buttery. This increased and near the week and a half to two week mark it started smelling like peanut butter mixed with urea. Quite weird and rank.
I assumed it had got infected so took a sample. The sample smelled and tasted pretty normal. Quite darn nice taste infact and my gravity was at 1.017 so nearly there but going to leave another week and see if it goes lower. Lids been back on and a small amount of airlock activity since and more of the urea smell. The urea smell is pretty rank and I've never encountered this before. Every time my fermentation chamber is opened its not nice. I thought this will maybe condition out. I'm currently at about 2 and a half weeks into fermentation.
I did however find a couple things about urea that it is produced by yeasts and is a intermediate in the production of a known carcinogenic substance called Ethyl Carbomate. This is found in pretty much all fermented food and beverages in varying quantities. It sounds like it has no acute effect on human health but is a pretty bad carcinogen so I'm worried that even if this smell disappears during conditioning it maybe that because I'm getting a lot of urea smell there may well be a **** ton of this compound in the beer?
https://academic.oup.com/femsyr/article/17/7/fox072/4411803
https://en.wikipedia.org/wiki/Ethyl_carbamate
Has anyone ever encountered a urea smell from fermentation? The only things done different this batch are the new yeast variety and the use of the Wyeast nutrient blend (Which may actually contain urea)?
Could I have an infection?
Should I risk it or just ditch it? I was super excited about this brew as I've heard the yeast is awesome and was my first brew where everything in the process went spot on. Frustrating.
Thanks in advance peeps
Ben
Thanks peeps.