11.9.2016 – Yeast hybrid growth and the pursuit of fruit esters


Fancy title, eh?  Doesn’t it make me sound smrt?  

I was fortunate enough to have a fellow homebrew enthusiast send me a care package containing some of his excellent homebrews and some specialty yeast!  Thanks M00ps!!  Included were 2 vials.  One contains F1, a “rare mating” of Conan and WLP644.  The other contains F1/C4, a meiotic segregation of F1.  Supposedly the F1/C4 mix will ferment faster, but with less fruity aroma.


I initially learned of this hybrid over the summer from homebrewtalk.com user “SureGork” from Finland.  I jumped over to his blog (http://beer.suregork.com/?p=3747) and pulled together what information I could gather.  There is lots of evidence supporting his claim that this is an actual hybrid and not a blend.  His goals were to develop a yeast strain with lots and lots of fruity esters, high attenuation, fast fermentation, and moderate flocculation.

I’m not the first to use this yeast, but this will be my first time veering into the WLP644 style of things.  I’ve read of a man in Germany winning homebrew contests with this strain overseas so I am pumped to try it out.  Lots of positive feedback from other people using the strain that made it across the pond to the states as well.

Yesterday, I brought the vial of F1 to room temperature and created a yeast starter on my stir plate.  My goal is to step this up several times in order to cultivate enough yeast to store for future use as well as pitch in a NEIPA.


Day 2 – 24 hours later there is no activity in the starter.  I guess he meant it when he said it’s a slower fermentation.  Let’s hope that the wait is worth it!  In case I made the starter too strong, I diluted the solution by 20%.   Apparently I am not the only person to experience this lag time.  This is reminiscent of starting some dregs from a can.

Day 5 – No visible activity.

Day 7 – I cold crashed and decanted the top fluid.  I took sample to taste and it wasn’t sweet at all.  This must have just fermented out very quickly.  Tasting notes of straight orange rind / clementine.

Following day 7 I stepped this up with 200ml water of 1.030 wort every 48 hours for 6 days.  This yeast is violently aggressive.  Like Conan, it’s not much of a top cropper.  I foresee a direct pitch of this finishing a 1.060 beer in 3-4 days at ambient temperature (this time of year it’s about 62F).


Day 14 – I wound up with 1000ml.  I cold crashed, decanted the top beer, poured half the yeast to a jar for later use.   I gave the decanted beer a taste and it was very significantly dry orange peel.  I will build the starter once more for a direct pitch.  I feel this yeast will work excellently with “Main Squeeze” one of my primary Pale Ales.  I will use F1 instead of my go to wy1056 yeast.  Stay tuned for that brew day.




2 thoughts on “11.9.2016 – Yeast hybrid growth and the pursuit of fruit esters

  1. Would love to ask you, since you’ve worked with cultured tree house yeast as well as the WLP644…. have you ever been able to get the “bubblegum” or “marshmallow” flavors that Tree House yeast is so known for? Anything that comes close? Thanks, Phil.


    • Not yet, unfortunately. I haven’t used the Tree House yeast since late summer. We kind of went on a Conan kick! When I was using the Tree House yeast, I was primarily fermenting at ambient temperatures. I’d like to see if I could coax those esters out at higher temperatures. I’d also like to do another side by side with WY1968. From my research, I think WY1968 could be a potential candidate for the Tree House yeast’s identity. It’s certainly not WY1318 and it’s much more flocculant than Conan, but exhibits similar properties.


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