Saccharomyces Trois (wlp644) - A Neutral Strain?

[BlochBaron]

Has anyone out there pitched this strain (thinking it was Brett) with a killer wine yeast? I know that supposedly all ale yeasts will fall victim to the proteins created by wine yeasts to kill off the competition but that Brett strains aren't affected.

Given that this isn't exactly an ale strain, and was only recently classified as sacch - anyone have any evidence to say if it's neutral or susceptible to the killer strains?

I contacted White Labs but they said they don't know for certain yet.

Thanks!

 

[AK7007]

I also inquired with White Labs about this and they said that they don't screen their strains for killer status. I wanted to use 644 with Q23B for an IPA, and haven't been able to get it to grow in wort that also has Q23B (K2 killer factor active). I'm trying WLP648 instead now, but I don't have anything completed yet. Really, you should just try screening a bunch of different yeast strains since you never know which might be neutral.

If I was you, I'd try some of the experiments that I've been doing - I set up 4 250ml starters (my hydrometer cylinder is ~250), then put a few colonies of Q23 in one, a few colonies of 644 in another, and one with both strains. When fermentation activity ended, I measured the FG of each, and the one with both strains failed to attenuate properly, I don't remember the exact numbers.

 

[pricelessbrewing]

Find a sugar source that only wlp644 can ferment and the wine source can't, like complex sugars produced by high temp mashes. Ferment with two controls one variable batch and a forced fermentation tests for all three. This will give you a good indication of the FG for each batch. If the variable batch has a fg similar to the wine yeast only, then it killed the ale yeast, if it is more similar to the ale yeast batch then it didnt kill the ale yeast.

 

[Calder]

Has anyone out there pitched this strain (thinking it was Brett) with a killer wine yeast? I know that supposedly all ale yeasts will fall victim to the proteins created by wine yeasts to kill off the competition but that Brett strains aren't affected.

Given that this isn't exactly an ale strain, and was only recently classified as sacch - anyone have any evidence to say if it's neutral or susceptible to the killer strains?

I don't know that this is true. It has probably always been classified as a Sacc strain. It was just marketed as a Brett strain, but White Labs was called out on it.