Pellicle formation with Peg vs. Airlock

Back in may I got a healthy 2nd generation rosalaire yeast slurry from my barrel brewing buddy Zach. The slurry damn near filled up a two liter soda bottle, and feeling adventurus, i whipped up a 10 gallon Oud Bruin based off of JZ’s recipie in Brewing Classic Styles…a month later I racked it off the yeast(well probably mostly bacteria) cake and got it into secondary.  The slurry went in the fridge only to be neglected until mid september only to go to yet another barrel brew brother where it seems to have found it’s feet again and ferments madly away in the 80’s on some other flanders esque style beer…

Any way that’s not the point, the point is one of if the wooden peg is worth doing.  The thinking behind the wooden peg is that in the context of ration’s the surface area of a simple wooden peg in the opening of the carboy, is roughly equivalent to the surface/volume ration of a full size wine or bourbon barrel.  But all of that is debatable without an actual experiment…so here we find ourselves in the asle of home depot looking at oak stair balusters….”one or two?”  Well in the name of all things science, we hold off and only buy one, which we then chop down to the right length to dip into the beer, and not stick out of the top of the carboy…initially there was no difference, they both did nothing, but right around a month or so after racking, there started to be the little white pools on the surface of the beer.  Then as with all good flanders beers, I forgot about it, not on purpose, just went off and forgot about it properly.  During this forgotten time, it was summer(albeit a mild one) in dc, we didn’t run the AC much and it was in a cool dark room.  Probably saw low 80’s but mostly mid-70’s due to the nice tile floor in the room it lives in.

When I came back to it, you can see the dramatically different pellicle thicknesses, neither beer looks ropey in any way, just a nice hard looking pellicle.  I haven’t tasted either version yet(will do that tomorrow when Alex and I are brewing the beer(a sour belgian single) to replace the flanders red that is ready to come out of the barrel).

In any event, it is interesting to see the difference AND it will be yet another aspect of the oud bruin, cause now I will be blending back the two versions to get the sourness/funkiness to a desired point….another flavor control lever if you will.

Pictures tell it all…

Edit: Thanks to Michael Tonsmeire for part of the inspiration to do half the batch with the peg vs. the other half with the traditional air lock.

Wooden Peg generating a more significant pellicle than a traditional airlock

Traditional Airlock NOT generating the same degree of pellicle