New wort on "old" yeast?

[kev211]

Ok, so I brewed 10 gallons of my Christmas milk stout last weekend (OG 1.073). I split it between 2- 6 gal fermenters and pitched WLP001 from a starter into each batch. They've finished up now and are sitting around 1.022.

Here's the question... I'm gonna keg those beers this weekend and brew another 10 gallons of the same exact beer. If I were to add the wort right on top of the yeast from the previous batch, would I be stressing it too much? Or am I better off starting with new yeast/starter?

I've seen other threads saying not a great idea do to trub/hop carryover, but since this is the same exact beer with no dry hops that may differ

 

[FromZwolle]

I've seen other threads saying not a great idea do to trub/hop carryover, but since this is the same exact beer with no dry hops that may differ

nonsense. this is perfectly fine. you'll want to wash the yeast after the second pitch, but fresh wort on a yeast cake is one of the best ways to re-use yeast, and is especially great for high gravity brews.

 

[Qhrumphf]

The issue isn't as much carryover as potentially excessive pitch rate including a higher amount of non viable yeast. Lots of pathways for problems.

When I do this, I go from a low hopped low gravity beer, and then add a very high gravity beer on top. Say a 1.035 Scottish Ale cake getting new wort for a 1.095 Wee Heavy.

As you're going high gravity it makes sense. Starting from a high gravity at the same time will work against you though since that'll be starting with more stressed yeast.

 

[Qhrumphf]

And washing typically does more harm than good.