Thu, Oct 29, 2015

Cider Cave Construction

How do you control fermentation temperature when all you've got are IBCs in a hot steel building? Build a huge box.

In the summer of 2014 we had to make a big decision prior to apple harvest: Would we do another season of practice batches, honing our skills and gaining experience, or would we make a batch we could legally sell. We very nearly chose the former, but based on the advice of my 95-year-old grandmother, we decided to go for it.

We rented an apple press, bought 25 bins of apples, and produced 5000L of juice. We didn’t have any sort of license yet, so we took the juice to a giant freezer warehouse to chill out until we could figure out what to do next.

After 8 months of applications, fees, inspections, more fees, more applications, and a lot of waiting, we had our very own Manufacturer’s License from the Liquor Control and Licensing Board. We could finally take our juice out of stasis and start making cider.

Sketching the plans

One problem: it was summer and getting to be 40°C in our little cider building on the farm. Not ideal conditions for happy yeast to ferment our juice.

Our solution was to make this insulated structure sized perfectly for our five 1000L IBC tanks. We consulted the municipal building inspector who advised us that we could avoid building permits if we could keep the square footage under 108 sq ft. That turns out to be pretty much exactly the size required for these five tanks, with no room to spare.

We framed it with 2x4s and finished it with drywall. Each side is connected in such a way that the whole thing can come apart if we need to move it. That was a good idea, because Mike needed to do just that to re-seal the concrete floor a few weeks after erecting this.

To allow access to the cave, we put hinges on one side of the top. The idea was to use the significant weight of the lid to squash down on a foam gasket running along the top of the walls to make a good seal. The seal worked pretty well, but the lid was SO DAMN HEAVY. It was difficult to lift and super dangerous to prop open when working inside. After a month, we cut the front wall in half so that it could swing open.

Hanging off the back of the structure are two run-of-the-mill window-mounted air conditions that we salvaged from Mike’s parents’ basement. Next week I’ll post about how we hacked custom electronics into these air conditioners to improve their performance, essentially turning our cider cave into a walk-in cooler.

Posted on Thu, Oct 29, 2015 by Luke Cyca