Ben’s Model of our Butcher Shop
To show his grandparents at Christmas what we have been up to this year our son Ben built a model of our on-farm Butcher Shop. I snapped some photos while he was in the early stages of working on his project. He made his model out of layers of plywood which he routed out using a hand drill to carve the shape of each room from the layers of wood. Using Ben’s model I can give you a guided tour of our new on-farm butcher shop, slaughterhouse and smokehouse.
Similar Perspective View of Floor Plan
The massive yet compact structural building is now finished, that is to say it is closed in and the interior is no longer exposed to the elements. This allows us to continue construction work through the winter on the interior details. We finished the structural building in the beginning of December, putting up the last ring of walls and the flat poured concrete roof.
We have poured a total of approximately 1.6 million pounds of concrete. Like with our cottage, almost all of that thermal mass is inside the insulating envelope. This will make for a very thermally stable structure where it is easy to heat the administration and abattoir (red) sections while also being easy to cool the reefer (blue) section of the building. In fact, we’ll be transferring the heat from the heat of the carcasses and machinery from the cold reefer section to the warm portion of the building. Waste not, want not.
Open the Roof and See All the People!
With the roof ripped off lets take a peak inside…
To the near right, that is to say the south west corner, is the upper mechanical room and the abattoir loft. This is where the 20′ high rail will go in the abattoir, a.k.a. kill floor. The loft lets us easily and safely work on the upper part of a hanging carcass for beginning the process of skinning large beef as well as big sows and boars who are too large to fit in the scalder.
On the left is the coolth attic showing the vaulted ceilings of the work rooms. For the next several years the coolth attic will remain an unfinished space space above the the carcass chiller, raw process cutting room, fermenting cave, brine room, cooler and freezer. The whole reefer area is super insulated for energy efficiency and has a very high thermal mass. It is built as thermos bottles within thermos bottles, rather like Russian dolls.
Someday we’ll build large fluid filled tanks in the coolth attic.[1, 2] Think of them as four decent sized indoor swimming pools. Except, these tanks will be chilled down as low as 20°F below zero during the winter jumping over the energy cliff of the freeze point, also known as the heat of fusion† to those who like playing with refrigeration. That would make for very chilly swimming. These tanks will be powered by Dark Panels a.k.a. Lunar Panels. The idea is to feature our farm’s biggest flaw: winter. By storing the deep cold of winter in a large insulated box and then slowly releasing it down into the reefer during the warmer months we’ll be able to use less electricity to chill carcasses and keep our building cool. Basically our reefer will be sitting under a giant super cold ice cube like grandma’s old fashion ice box that had a block of ice in the upper cabinet. The difference is that our ice will be far colder, far larger cubes and we’ll only get delivery once a year – each winter.
First Floor Work Rooms
Lifting off the upper ring of walls we find the first floor work rooms of the butcher shop. All the interesting stuff happens down here. But lets back up a moment… The process of turning pigs into pork for your fork actually begins ten months before market day with the breeding of a sow and boar. Three months, three weeks and three days later we are witness to the miracle of birth of a litter of piglets out in our pastures. After another six to seven months of growing those three pound piglets turn into 250 to 300 pound hogs who have rotated through the pastures of Sugar Mountain.
The day before slaughter we will herd the selected market age livestock into the lairage. This is a holding area just south of the abattoir where the animals can rest the night before. This puts them into an ideal calm state.
On slaughter day, which is just once a week for us, the animals will enter the kill box in the abattoir, a 16’x16′ by 20′ tall room in the south west corner of the building, one at a time for humane stunning, bleed out, scald & scrape, evisceration and cleaning all under the watchful eye of the inspector.
If we were just doing typical market size pigs we would not need such a high ceiling. The tall abattoir gives us plenty of room for a high rail with a hoist for large animals like our big boar Spot who topped out at 1,700 lbs and 12′ long – think short legged beef although he had tusks rather than horns. This 20′ high rail is tall enough to hang full size beef and other large animals we might raise in the future.
Floor Plan spun around for easier reading
Within the abattoir there are two small, isolated mechanical rooms on the left which aren’t visible under the loft. I should have flipped the pieces of Ben’s model over for the photos because the undersides show all the details Ben had carved out for the spaces such as the mechanical closets where we isolate loud or fire risk machinery like compressors and phase converters. These closets protect us from their noise and protect the machinery from the wet and corrosion of the kill floor which must be washed down with 180°F hot water and organic acids for sanitation. These do nasty things to bacteria and plain steel – thus why we use stainless steel and isolation.
After slaughter the cleaned carcasses move north along the second rail, a 12′ high middle rail, from the abattoir into the carcass chiller shown in the north west of Ben’s model and the floor plans. That room is 19′ long, 6′ wide and 15′ tall which allows for the refrigeration system to be mounted above the rail for maximum efficiency.
Overhead View before Closing in
The refrigeration engineer we are working with just visited this past week after not having seen the building for a year and a half since his initial site visit. I had brought him in early in the project to get feedback on my ideas so I could make sure I was constructing the building in such a way as to work well with his refrigeration system needs.
Top View of Construction in Progress
Last time he was here the butcher shop looked like the two photos above, about half done. A lot had changed and he was delighted. Everything was built to meet his needs with high arched ceilings that focus the heat to the evaporator getting rid of dead spots, divisions of functions and super insulated high thermal mass rooms containing all the necessary drains and conduit for refrigerant lines, electric lines, control lines and sensors. He loved the cast in place stainless steel threaded sockets in the ceilings which will make hanging his evaporators a breeze.
The north end of the carcass chiller can be sectioned off for dry aging beef for up to a month. We dry age our pork for one week by cutting last weeks pigs this week and slaughtering the pigs this week for next week’s cutting. When we start doing beef and then lamb again I want to be able to give the meat a proper aging space for maximum quality. Aging must be done at just the right temperature and humidity to avoid excess shrinkage and prevent the growth of bacteria while still allowing the meat to tenderize – something it won’t do at too cold a temperature. Thus the dedicated sectioned off space for aging separate from the carcass chiller.
Cutting Room Looking East into Cave from Carcass Chiller
Initially we’ll be doing our meat cutting in what will later become the warm kitchen and smokehouse in order to get up and running as quickly as possible. When we move into the final 10’x14′ by 10′ tall cutting room it will feel spacious. To learn the art of commercial meat cutting we apprenticed for 18 months in butcher shops that had rooms far smaller than even the initial meat cutting room’s 5’x16′ by 10′ tall size.
Continuing east from the cutting room we find the fermenting room also known as the cave or cold kitchen. This space will be divided up into ten insulated cabinets which can be temperature and humidity controlled for making prosciutto, pepperoni, summer sausage, brawn, dry aged hams and all sorts of specialty value added meats. My goal is that each cabinet can hold 300 to 600 lbs of product. Some products take a week and some take a year to cure. An eleventh and twelfth cabinet can be used for chilling product coming out of the double smokehouse prior to slicing and packaging.
Looking at Ben’s model you’ll notice a long thin room along the north side of the building. That is where we’ll build the FCB – that is to say Freezer / Cooler / Brine room which is accessed off of the cave.
In the north east corner of the reefer, the first or east most room of FCB, is the brine room where we’ll do dry salt rubs, corning, wet brining and all those delicious sorts of traditional meat preparations for smoking and aging. This room will have space to allow us to brine whole roaster pigs so they’re ready to grill for graduations, birthdays, harvest parties and other events. We find that two of the things roaster customers struggle with is how to brine a large pig and how to keep it chilled for the required time period prior to putting it over the coals. We hope that by being able to brine roasters to customers specifications we’ll help people focus on their event and pig roasting fun.
West of the brine room is the super cooler where meat is held fresh at 27°F. Meat freezes at 25°F rather than the 32°F of pure water because of the salts in the blood and intracellular fluids. Research has shown that the quality is much higher if the meat is kept at 27°F rather than standard refrigeration temperatures in the mid-30’s F. Check out this article for details. The cooler is also where meat is pre-cooled before entering the freezer. This allows the blast freezer to more easily and quickly jump the energy cliff to frozen.
The blast freezer is the most deeply insulated space in the building at the west end of the FCB. It is the inner most sactum contained within the cooler which is contained within the brine room which is inside the reefer which is inside the structural building. Each bottle is insulated from the next one out so that the most inner bottle, the freezer, has R-100 insulation. As the refrigeration engineer said – “Wow! We’re not losing heat there!” The idea is that any ‘coolth’ must leak out through the adjacent rooms where it will be most useful thus saving energy. Our first refrigeration system will be in the freezer, pumping heat out of there and back to the administration section to heat the inspector’s office and pre-heat our hot water.
What makes a blast freezer special is that it rapidly pulls the temperature of the product down past the freezing point thus producing micro-crystals of ice rather than the longer dagger like crystals that come from slow freezing.[1, 2, 3] Small crystals better preserve the cell walls which enhances meat quality and prevents bleed out of the inner cellular fluid in the meat. You know how when you thaw meat there is a lot of fluid? Well that’s the damage caused by the ice crystals puncturing the cell walls. Micro-crystals prevent this. Once frozen it will be held in a deep freeze at -25°F which gives a virtually indefinite shelf life.
You might be thinking that the freezer is tiny. You are right. We operate primarily on the Just-In-Time farming model where the meat is harvested and quickly sold. We sell almost all of our meat fresh so there isn’t a lot of need for frozen at our farm. Thus a small freezer fits our needs. We do need some freezing capacity for our individual customers buying for home consumption who want to buy frozen meat so that their smaller freezers won’t have to work so hard. This provides them with better quality and an energy savings since our equipment is more efficient. When we mail meat it will also be nice to be able to pull it down to a very low temperature before applying dry ice (-109°F) and shipping.
Heading south out of the brine room we pass back through the cave and out of the cold reefer into the warm administration section. The smokehouse will be on the east outside wall. It will be large enough for us to smoke and BBQ whole pigs for events as well as smoking hams, bacon, kielbasa, hot dogs, trotters, hocks, ears, our meaty ribs, bones, jerky and assorted other tasty pig parts.
In the same area but to the right is the warm kitchen where we can render lard, prepare sauces, make stock, can and do other small batch cooking projects.
Last but not least is the inspector’s office and bathroom off of the entry hall.
The building is poured on a floating slab on top of the old hay shed foundation anchored strategically at the edges. The foundation of the butcher shop is isolated with insulation from the old foundation and thus from the earth. One might think we would want to tie the building to the earth ground temperatures but unfortunately the earth is too warm for the reefer and too cold for the office. The earth floats around 45°F to 55°F. A strong thermal connection would bleed heat away from the office which the inspector would like kept at 65°F and it would force the refrigeration equipment in the reefer to run constantly as we tried to avert global warming.
Bright idea! Short circuit the earth and just pump the heat of the reefer directly to the inspector’s office. This lets us keep the inspector toasty warm and the meat below 41°F as required by the USDA regulations to inhibit the growth of bacteria.
The butcher shop does take advantage of the tempering effect of the earth by nestling into the hillside so the exterior is a near constant 50°F or so year round for much of the building’s surface area. That means we don’t have to fight with the summer high of 86°F or the winter low of -45°F for those surfaces. The rest is super insulated to protect the high thermal mass of the building from fluctuations.
One funny little thing about the butcher shop being nestled into the earth is that from our vantage point looking down from our cottage it doesn’t look all that big. But from the the road side it looks, to put it in the words of several visitors, like a skyscraper. One fellow asked why we’re building a three story high butcher shop. Ben replied, “It’s complicated.”
The Real Deal
Doors arrived this Wednesday. Will and I mounted them the front hall leading out to the inspector’s parking area and from the abattoir to the lairage. They have full double pane low-E glazing to let in natural light. I would have liked triple pane but couldn’t find them in the specs I wanted. The new doors will improve our heat retention – previously we just had double layers of 4 mil plastic sheeting with an air gap to keep the warmth in the building. Even with only that the interior of the butcher shop is floating around 38°F at the sub-slab insulated below the reefer, 41°F at the interior floor level and 46°F at head height in the administration section. That’s pretty good. We’ll need to raise that temperature about 10°F for when we’re applying the epoxy finish. But for doing regular construction that’s toasty warm.
Outdoors: 12°F/-4°F Sunny
Tiny Cottage: 66°F/62°F
Daily Spark: Experience is something you don’t get until just after you need it. -Steven Wright
†Okay, okay, so yes, I admit it. You caught me, I really am building a cold fusion reactor up here on the mountain… The rumors were true.