off flavor

[jefferym09]

i taste tested my belgian wit today and was confused. The last beer i made was a blonde ale and it had somewhat of a vegetable/rotten pumpkin or squash smell and taste to it. i thought this was just how the blonde was supposed to taste. But now this beligian wit i made tastes almost identical to the blonde. Am i doing something wrong?

 

[TarheelBrew13]

Sounds like dimethyl sulfide. Did you happen to use Pilsner malt and a 60 min boil? If not, are there any other similarities between the beers such as grains, boil times, yeast, aeration etc.? Also, are you getting these aromas in the final carbonated version or are they still fermenting?

 

[jefferym09]

yes i did use 5 lbs. german pilsner malt. the rest was flaked wheat, white wheat, or oats. there's not really any similarities between my two brews as far as malts go. i did do a 60 min boil time on both. the yeast was different, how do you aerate you beer differently? i always just shook the carboy around after the yeast was in the primary...

 

[maida7]

Did you boil with the lid on? Was it a low simmer or a big rolling boil?

 

[TarheelBrew13]

Pilsner malt produces more dimethyl sulfide than other base malts and is why most brewers suggest a 90 boil when using them. This allows the compound to be evaporated off and is why the previous poster wanted to make sure you had a nice rolling boil with the lid off.

If you're using a traditional wit recipe with a wit yeast like ylp400 then your off flavor could be hydrogen sulfide which is readily produced by that yeast at higher fermentation temps. If you can't lower the fermentation temp for your next wheat, try swirling the fermentation vessel twice a day for about a week after fermentation is complete. This agitation helps the extremely volatile hydrogen sulfide come out of solution.

Other techniques can help reduce off flavors. Aeration helps a lot. I use an Oxygen tank from the hardware store and a Williams brewing kit that I got online. Shaking will work but you have to vigorously shake the carboy for 5 minutes and I find that too taxing for me.

Yeast nutrients can help, especially in beers with large amounts of unmalted grains like Belgian wits. I like the wyeast nutrient.

Good luck with your next brew. I think we all have problems with off flavors when we start.