[erockrph]

I was under the impression that Orval filtered out their house yeast and added Brett at bottling, but I have a starter going with some Orval dregs and now I'm not so sure. I stepped it up last week and now the starter is really roaring along. It has a huge frothy krausen, and is pumping out quite a bit of CO2. It smells Bretty and fantastic (apple/pineapple/cherry), but it definitely looks more like a Sacc fermentation. Either this is a mixed culture, or it's the world's most vigorous Brett strain.

Does anyone know if there's Saccharomyces in Orval dregs? Anyone make a starter from Orval before? I was planning on pitching this along with some US-05 in a lambic-style brew, but if there's already some Saccharomyces in this culture, I'll probably pitch the whole starter into primary.

[S. cerevisiae]

It's a mixed culture.

[homoeccentricus]

Main yeast is sacch, bottle yeast is brett, but if you make a starter from the bottle, it's very well possible that the remaining sacch in the bottle multiplies much quicker than the brett.

[reverseapachemaster]

I know if left unstirred/shaken a starter from Orval dregs will form a pellicle. With oxygen brett will form a krausen and look similar to a sacc strain.

Orval is not filtered but centrifuged. I would imagine the vast majority of yeast in the bottle is brett. I've seen a few people plate out Orval dregs and find pedio as well.

[narcout]

Below is what Kristen England said about it on the NB forum a few years ago.  The full thread is here: http://forum.northernbrewer.com/viewtopic.php?f=4&t=40289&start=15

Fermentation
Orval pitches the Bastogne yeast for primary at about 3million cells/ml wort which lasts about a week or so at quite a cool temperature in 60-62F. They then spin most of the primary yeast out and adds the Brett (B. Brux) in secondary at 1000-5000 cells/ml. It stays in this 'holding' tank for about 3 weeks at 56F. Let the beer stay in the sencondary and then add the dry hops for the final week.

Bottling
The beer is now polished (centrifuged/ 'filtered') which leave it basically clean. They they repitch both yeasts at the same rate they pitched before which will have the following make up:
Main fermentation yeast : 3 millions cells/ml
Brettanomyces : 1.000 to 5.000 cells/ml

[erockrph]

Below is what Kristen England said about it on the NB forum a few years ago.  The full thread is here: http://forum.northernbrewer.com/viewtopic.php?f=4&t=40289&start=15

Fermentation
Orval pitches the Bastogne yeast for primary at about 3million cells/ml wort which lasts about a week or so at quite a cool temperature in 60-62F. They then spin most of the primary yeast out and adds the Brett (B. Brux) in secondary at 1000-5000 cells/ml. It stays in this 'holding' tank for about 3 weeks at 56F. Let the beer stay in the sencondary and then add the dry hops for the final week.

Bottling
The beer is now polished (centrifuged/ 'filtered') which leave it basically clean. They they repitch both yeasts at the same rate they pitched before which will have the following make up:
Main fermentation yeast : 3 millions cells/ml
Brettanomyces : 1.000 to 5.000 cells/ml

Thank you! That is exactly what I was looking for.