Same Batch, Different results

[HopsnHoes]

Brewing 10 gallon batches using the BIAB method. I divide the wort into two buckets for fermenting and add the yeast (US-05 dry).

Both buckets are fermenting side by side and when it is time to keg the beer, one bucket is clearly more robust in flavour than the other. After the two weeks of carbonation when the beer is complete there is a clear difference/winner between the two kegs.

When I brewed an IPA one keg had a strong malty finish, while the other keg was hoppy.

When I brewed a Saison one keg was a citrus hop taste while the other was lacking in any flavor.

Is there a way (aside from fermenting as one) to insure more consistency in the flavour?

 

[ProblemChild]

before or after boil?

 

[HopsnHoes]

The batch is divided after boil. Once the wort is chilled to fermenting temp, it is divided into the two fermenting buckets, given a shot of oxygen, and then the yeast it sprinkled over top.

 

[Oginme]

How are you splitting your wort between the two buckets? This may have some bearing on how it is fermenting if one bucket gets the bulk of trub or residue from the boil kettle. However, I would be more suspect on the buckets themselves.

I would start by checking the buckets to make sure one does not have some residue or scratches on the inside which may be harboring bacteria or other yeast strains. It may be better just to get two new buckets to rule out any contamination. Labeling the buckets so that you know which part of the wort is going into which bucket is a good way to track if one bucket consistently does not turn out they way you intended the beer to taste/smell. Making sure that you fill both evenly and split the yeast evenly (or add a full packet to each fermenter). During fermentation, check the seal on each bucket to ensure you are not getting an ingress of air.

Basically, this is a troubleshooting mission and you will need to watch all variables carefully until you are able to chase down the issues,

 

[HopsnHoes]

before or after boil?

The batch is divided after boil. Once the wort is chilled to fermenting temp, it is divided into the two fermenting buckets, given a shot of oxygen, and then the yeast it sprinkled over top.

 

[HopsnHoes]

How are you splitting your wort between the two buckets? This may have some bearing on how it is fermenting if one bucket gets the bulk of trub or residue from the boil kettle. However, I would be more suspect on the buckets themselves.

I would start by checking the buckets to make sure one does not have some residue or scratches on the inside which may be harboring bacteria or other yeast strains. It may be better just to get two new buckets to rule out any contamination. Labeling the buckets so that you know which part of the wort is going into which bucket is a good way to track if one bucket consistently does not turn out they way you intended the beer to taste/smell. Making sure that you fill both evenly and split the yeast evenly (or add a full packet to each fermenter). During fermentation, check the seal on each bucket to ensure you are not getting an ingress of air.

Basically, this is a troubleshooting mission and you will need to watch all variables carefully until you are able to chase down the issues,

Both buckets are new and the yeast is measured out evenly for both (purchase yeast by the brick). Prior to pouring the wort into the buckets it is stirred to create a whirlpool effect then divided evenly 10 liters at a time.

I may have to look into finding a way to ferment in 1 vessel and not 2.

 

[RM-MN]

When you put two fermenters in a fermenting chamber you get to control the termperature of one of them with the probe attached. The other one runs wild. It shouldn't make a ton of difference but it could be enough to notice. If you have the time to do so, brew just one 5 gallon batch and let it have about 4 days in the controlled fermentation chamber, take it out and then do the second one. You then have the possible differences in the mash but the fermentation temperature would be controlled the same for both.