March 13, 2013

Yeast Project: Culturing RAM 3, 5 and 8

The next three strains I am going to try to grow up are RAM-3, RAM-5 and RAM-8. I chose these three strains together because I thought they had the most in common of the remaining strains. I'm still running experiments of three strains at a time because I have limited time thanks to my bar exam preparation and it's enough work to step up three strains at once.

RAM-3 and RAM-8 are both strains identified as coming from the Exchange Brewery in Sheffield, England. This same brewery is indicated as the home of S-04 and other strains identified by Wyeast and White Labs as Whitbread strains. It's possible one or both strains I have share the same origins as these commercially available strains. It's also possible both strains are the same strain. However, the Exchange Brewery made a lot of beers so it's possible these two strains are entirely different from each other and the Safale/Wyeast/White Labs strain. Not only does it make sense to taste these two strains head-to-head but I'm also brewing several beers with S-04 so I can taste them against S-04 to see how similar they are to what is already available. The worst thing that happens is I end up with a couple back up first generation sources of S-04.

I also chose RAM-5 for this round as well. It's identified as a "Pabst ale yeast". I'm pretty sure that means it's an ale strain, which makes it a good choice to taste alongside the two English ale strains. Pabst made an ale once upon a time, so it's possible this is the yeast they used for that particular beer. Of course, it could be a lager strain mislabeled and I'll end up with yet another lager strain to make light lagers (which doesn't seem likely).

Process

The process here is identical to the process for the first run. I am filling a four dram test tube roughly 60% full of 1.030 gravity wort and adding the yeast sample. Then loosely covering with the lid and manually aerating as frequently as possible. The significant difference here is that I am using light DME with a slight hop addition rather than using runnings off another beer. I hope this way I can reduce the amount of sediment in the test tube as well as the slurry off the test batch.

Notes


1/25/13: added yeast to 2.5 drams of 1.030 extract.

1/26/13: periodic shaking for aeration after 24 hours shows no sign of krausen yet. By approximately hour 30 each was showing some trub in the bottom and some slowly bubbling foam that didn't look a lot like krausen but seems to indicate fermentation.

1/27/13: Visibly appearance is the same. Smell is slightly yeasty but also still some sweet malt aromas, suggesting there is still some fermentation left to occur before the starters dry out. Expect to let sit until Tuesday, at which time I will transfer them to their test batches. I should have an oatmeal stout in the fermentation chamber so the test batches will fit along side it.

1/29/13: All three yeast showing clear signs of fermentation with RAM-5 appearing to be completed. Prepared 14oz of 1.040 wort for each strain and added part of each vial to a mason jar of wort and covered with sanitized foil. Added to fermentation chamber at 65F.

1/30/13: After roughly 24 hours RAM-8 is showing a nice thick krausen but the other two are still.

1/31/13: RAM-8 still visibly fermenting. Both RAM-3 and 5 are showing a small amount of bubbles at the surface of the beer along the edges which suggests fermentation is slowly starting.

2/1/13: RAM-8 and 3 are both showing strong, visible fermentation but RAM-5 is still mostly still. I will try to agitate the yeast and add yeast nutrient at the end of the day if it is not showing additional activity.

2/2/13 (AM): RAM-5 was not showing any signs of fermentation last night so I added some yeast energizer and agitated. Hoping for some activity soon. If nothing show I will add the remainder of the initial sample and hope it takes off from there. Both RAM-8 and 3 are fermenting well. RAM-3 smells bready while RAM-8 has a fantastic fruity character right in the middle of an English and Belgian strain. It's surprising to get that much ester character out of the strain at 65F while S-04 is practically neutral at that temperature. May be an effect of underpitching in these experiments. Certainly deserves more experimentation.

2/2/13 (PM): Not seeing any activity out of RAM-5 I went ahead and added the remainder of the initial culture and left it out of the fermentation chamber at ambient temperature. After a few hours krausen was beginning to form so I returned the fermentor to the fermentation chamber.

2/4/13: All three beers appear as though the majority of fermentation is over. The krausen has risen and fallen. Each smells different but each delicious in its own right. I'm going to let it ride the rest of the week in the low 70s to wind up fermentation and clean up along with the stout in the fermentation chamber. Expect to bottle at the end of the week.

2/25/13: Finally got around to bottling each strain. I didn't mean for them to sit for so long but I also don't think it will affect the results. Bottled each in a 12oz bottle with priming sugar after taking gravity reading.

  • RAM-8: Aroma is malty and apricot-y. Some carries over into the flavor but there is some sort of skunky character to it that may go away after carbonation. FG: 1.012
  • RAM-3: Aroma slightly malty. Flavor is fairly neutral with hints of esters. Should clean up into a fairly neutral ale strain after carbonation. Definitely has a drier mouthfeel than RAM-8. FG: 1.01
  • RAM-5: Strong ester aroma with slight skunk with almost a cheesy aroma. Flavor is fruity and sweet, definitely a thicker beer. FG: 1.02 
3/6/13: Due to a minor accident in the fermentation chamber the bottles of RAM-3 and RAM-5 broke before opening so I will need to rebrew them along with the next batch of yeast I grow up.

0 comments:

Post a Comment