New wort on a wild yeast cake?

Maybe this is a dumb question, I know people empty barrels all the time and dump in new wort or fermented wort but...

I transferred a sort of hybrid smoked/english IPA/old ale to secondary and added a packet of Roseleare about 9 months ago. It has reached terminal gravity and has a nice faint sourness (went from about 1.017 to 1.009 on the Roseleare, never had a real pellicle). I want to bottle it this weekend and was planning on brewing a Flanders Red to put directly into this newly empty carboy. Is this kosher with wild blends? Should I aerate? It is a 5 gallon carboy, should i expect a big krausen with Roseleare as a primary yeast...i.e. should I transfer the yeast to a larger carboy first?

Thanks!

I have never done this, so YMMV, but my understanding is that the sour blends (esp. Roselare) tend to get better after a few batches on the same cake/reused yeast. The proportions of bugs will be totally different from what you originally got in that smack pack, so you can't really recreate the same thing twice in a row off the same cake. I don't know how many times it's ok to reuse, but I'm planning to do next year exactly what you proposed, once my Flanders Red is finished fermenting...

BTW, I'd put it into a larger carboy. Roselare has a blend of both sacc yeast and other stuff, so your initial fermentation will look just like you pitched on a cake of WLP001 (which is I think what they use as the "base" yeast in that blend or something similar). Assuming you ferment as "normal," you'll need the headspace. The sour stuff will kick in later after the initial fermentation is done. Not sure about aeration. The sacc yeast will like it (and may throw off flavors without it), but the other bugs in the blend typically won't need it. If it were me, I'd probably skip it to try to keep the sacc yeast down a little and leave something for the others to eat. Plus, since you're pitching on a cake, they won't need so much O2 to propogate anyway... Just my $0.02. Like I said, I've never done it before, so YMMV...

Follow up:

I just read a REALLY great blog post here on brewing sours at home: http://madfermentationist.blogspot.com/2009/11/brewing-sour-beer-at-home.html

The author is on this forum, I think his name is "Oldsock." (If he's reading this, I hope it's ok to link to your blog--it needs to be shared with the sour brewing masses!). Anyway, he specifically discusses pitching on a yeast cake from a prior sour batch in here (he says it's ok).

Well, I racked off my old sour (which has acquired a lot of acetic character since my last tasting a month or so ago) and bottled it. Brewed the Flanders Red (again as for all my beers, forgot to lower grain amounts and efficiency was way high and ended up with a SG of 1.070 instead of the 1.058 that the recipe had) and put it in a 6.5g carboy with 1oz oak cubes, aerated, and dumped in the cake from the old sour as well as 2/3 of a packet of US-56. Based on the sourness (mostly acetic) in the old batch, I thought this one might get too sour with just Roseleare, so hopefully the blend of US-56 and wild bugs make a nice balance. We shall see...in a year or so...

As of this morning (~15 hour post pitch) there was a 1cm krausen and slow bubbles from the blowoff. Will replace with an airlock as soon as fermentation slows, and leave on all the yeast for a long, long while.

Yep. saw that last week and went off what he said due to the lack of responses prior to brewday. Thanks for the info Munsoned!

Munsoned said:

Follow up:

I just read a REALLY great blog post here on brewing sours at home: http://madfermentationist.blogspot.com/2009/11/brewing-sour-beer-at-home.html

The author is on this forum, I think his name is "Oldsock." (If he's reading this, I hope it's ok to link to your blog--it needs to be shared with the sour brewing masses!). Anyway, he specifically discusses pitching on a yeast cake from a prior sour batch in here (he says it's ok).

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