Repitching: does relative OG matter?

I’m going to repitch some yeast that was last used in a 1.070 beer. Does the OG of my last beer affect how the yeast will perform in the next? Should I brew a beer with higher, lower,or the same OG? Does it matter at all?

Cheers,
Drew

That’s a high OG beer to reuse the yeast from. I can’t remember what the max OG is for reusing yeast, but I think your at the upper end. If I want to harvest yeast to use in other beers I make a lighter colored beer around 1.040-1.055. Having said that I’m sure it will work but may give some off flavors.

I’ve routinely repitched yeast from 1.075 OG batches into subsequent brewings of standard bitter and even low OG (ie., modern style) Mild ales and have never had any issues with yeast performance or off flavors. That’s over a period of at least 27 years.

When doing such repitches these days I tend not to push my luck and I stop after 5 or 6 brews. But I have definitely taken it much further than that…again with no issues at all.
Bottom line is that in almost 3 decades of repitching slurries, I’ve never had any problems going from stronger to weaker (and even going back & forth a few times).

It certainly may depend on the strain used but I can definitively say that it has posed no problems with my 4 most commonly used strains (WY1056, WY1968, ECY “Old Newark”, and my decades old house yeast (pedigree unknown).

As always experimentation is the best way to determine which yeasts would perform this way in your particular situation. For me, it was an experiment worth doing.

I don’t think it matters, based on my experience, but there are thousands of cautious theorists out there who do, so you be the judge. My advice is to play around and experiment on your own because it is the very best way to learn.

theoretically, wouldn’t hop content affect viability more than gravity? Dissolved oils will coat yeast cells and inhibit/prohibit growth/cell division.

Either way (ie with repitching from a hoppy or strong beer), I’ve had good results just by assuming lower viability with your yeast calculator of choice, hence pitch more slurry.

[quote=“Pietro”]theoretically, wouldn’t hop content affect viability more than gravity? Dissolved oils will coat yeast cells and inhibit/prohibit growth/cell division.

Either way (ie with repitching from a hoppy or strong beer), I’ve had good results just by assuming lower viability with your yeast calculator of choice, hence pitch more slurry.[/quote]

Good point about the hop oils…and also a very good suggestion for a solution to help allay any concerns about the viability.
:cheers:

Thanks guys. I’ll give it a go and see how it works.