O'so Brewday & 1 year mark.

Two major events occurred this weekend.  On Friday, we brewed the second batch of lambic up at O'so Brewing, and today marks 1 year from the day I filled that first pilot barrel.  Its crazy how much a year can make a difference.  I went from being thrilled to get a single barrel filled to frustrated we didn't fill 15 barrels on Friday.

I'm not going to outline the process or talk too much on the brewing itself as I would just be repeating the previous brewday.  Instead, I'll mention a few of the changes between the batches.  The last batch hit 1.040 gravity, which is fine, but its on the lower end of the spectrum.  This time we upped the grain bill and hit 1.054.  In doing this we also got a darker wort, and I really like the color that resulted.

Another factor that helped us hit a higher gravity was the evaporation rate during the 4 hour boil, which is higher in the winter than the summer.  While I am happy to have the higher gravity, we only filled 13 barrels.  A 14th barrel was filled half way, and we will use that to top off the other 13 barrels after the active fermentation stage finishes.  In comparison, last year we easily filled 14 barrels and had probably 1.5 barrels worth of wort that had no barrel to go into and therefore went down the drain.

Filling the inoculated barrels

We also changed the hopping.  Last year we used 38 pounds of 5 year old Liberty hops.  In sampling the lambic at 6 months old, it has a fairly pronounced hop character.  I know this will fade, and have seen that happen to my pilot barrel, but we wanted to dial that down a notch and used 30 pounds of 5 year old Willamette hops.  The hop variety was not an intentional change, but rather simply what was available.

Measuring out 30# and breaking up the whole hops.

The most significant change we made this batch was to not pitch yeast.  Instead, we took the lambic barrels from batch 1 and transferred the contents over to new barrels.  Then we filled the inoculated barrels with fresh wort and will let it ferment with resident yeast in the barrel.  The "new" barrels were used wine barrels, and we soaked them for a month in water to further extract any tannin and wine flavor, then steam cleaned them.  I realize this lambic is going into new barrels twice and so wanted to make sure to increase my effort to strip flavor from the new barrels.  To rack the lambic from one barrel to another, we used a Bulldog barrel transfer set up.  First we pre-charged the empty barrels with CO2, then used CO2 to pressurize the filled barrel and gently push the lambic over to its new home.

Transferring aged lambic into "new" barrels.

All in all, it was another successful brew day.  Although I was especially disappointed in not being able to fill that 14th and 15th barrel, it is good to reflect on the year and realize how far this project has come.  I am thankful to O'so for brewing this beer with me, and I look forward to our annual brew day.

A sea of barrels.  All but the 6 stacked are for lambic.

Update:
It took 4 days to kick in, but fermentation is foaming over.

It started with these two on Tuesday night, and by Wednesday morning all of the barrels were foaming.  While I like that there was a stressed fermentation that took a few days to start, the barrels were in the way of brewing operations and needed to be moved into the tap house.  However, Wednesday morning it was learned that the concrete floors in that area do not slope to the floor drain and all of the foam pooled up and poured into the adjoining room; Marc's office.  While I imagine it smells wonderful, it will require quite a bit of clean up, and the barrels were moved back over the floor drain.  Reminds me of the mess I had with the pilot barrel!