Silk City Distillers

Lots of unknowns here, what's your target ABV output, what's your product? What kind of time constraints do you have? By "hybrid" do you mean utilizing a packed column and trays? What's the packing material? If trays, how many trays? Bubble Cap or Sieve? Why are you even considering a hybrid approach (I would argue this is unnecessarily complex, since you need to engineer both the packed and tray columns to operate within the same set of design parameters for optimal efficiency). You are going to get a half a dozen opinions, at least. The hobby community has done a lot of trial-and-error design work on packed columns, and there are a number of rules of thumb with regard to column diameter and power input, column height to diameter ratios, hetp, etc that would probably help you. In the commercial world, much of this is either trade secret or so complex you'd wear out your slide rule. And … the diameter of the boiler is not relevant to column sizing.

Dig a hole. I recall the folks over at Koval saying they had one of their big stills in a pit due to height issues. All you need is one foot? Cut the concrete and go down. Split columns is nice, because they avail some other flexibility a single tall column doesn't, but generally the cost will be higher as the vapor plumbing is more complex, requires more valves to operate, requires dual dephlegmators, etc. Or, put in a skylight?

Unless your boiler was foaming excessively, and carrying a significant amount mineral laden water out the lyne arm and into the mash, I'd look elsewhere. The steam itself should be generally devoid of metals and minerals, and foaming is rare without other impurities being introduced. Did your low water cutoff trigger? Did you use an excessive amount of water? I'd look somewhere else regarding the unexpected drop in yield. Potential infection is always my first thought, but if you weren't able to maintain a steady power input into your pot, and were boiling in fits and starts, I can imagine all sorts of potential smearing between heads/tails/hearts. Seems like a long shot though.

As you are producing steam from your boiler (it's a boiler, call a spade a spade), you are leaving behind all the minerals and metals, etc etc that are not volatile. These will eventually build up to the point that you see, and will continue to concentrate until you start getting scale build up on your boiler walls and elements. If you have elements, you might notice them getting build up as well. This is why process boilers have blow down systems on them, to replace the mineral/metal laden water with water of a lower concentration. You should dump and refill. If you don't want to, you can use distilled water as well. If you have a reverse osmosis system, you can use that water as well. The higher the water purity, the longer it will take for the mineral level to build up. Careful with your homegrown boiler.

You'll still want to confirm allowable discharge temperature and pH with your local sewerage authority.

Let me know if you are interested in doing something with a less distinctive bottle type, we're only about 15 miles apart. That's an awfully nice jug style bottle though.

What always made sense to me from a workflow perspective was matching your mash tun and fermenters in a 1:1, and sizing your mash tun as a multiple of your still batch size. Our mash tun is sized for a double sized batch. 1000l batch sizes are nice because you can use IBC totes as holding tanks. Should you mash and ferment a double batch, it would be relatively easy to move half the batch to the still, and the remainder into the tote, so you wouldn't be keeping your fermenter in use a day longer than necessary.

I've heard similar challenges from the brewers around here, so the analogy approach could be double edged. In fact, we had to go out of our way to explain the differences between brewing and distilling, because the board had the perception that breweries of any scale produced nuisance odor in the neighborhood. We had to propose installing a carbon-based adsorptive dry scrubber on our fermenters as part of our odor control strategy. Anyone else using carbon dry scrubbers on their fermenters? I'd love to know if we're the first. Even the engineers at the big carbon houses were scratching their heads. Hinging your plan on the local government to change the zoning and law carries with it risk. Not only timeline risk, since those guys move at the pace of cold molasses, but also risk that the change be denied. Zoning and master plan changes are generally not fast actions, at least around here they are not. In addition, there is huge risk of the unknown, since once they open the door to allow it, approvals are no longer on a case by case basis. While we might think it's great, the local community might see this as opening the door to dozens of problem businesses. The biggest issue we faced from the local governments and zoning was a fear of the unknown.

Not following, are you trying to get the city to change the zoning to accommodate you, or are you going before the planing board for a variance to allow you to operate in a zone other than permitted? Similar story in our area, distilleries classified as permitted in the heaviest of heavy industrial districts. However, none of these areas are suited to our type of business. We found an ideally suited property in a Business/Commercial zone, and because of the zoning we needed to petition the board for a variance to allow us to operate. It required an Attorney, an Architect, and a Planner, as well as expert testimony from a distillery owner in another township. As expected, the major hurdles were potential negative impacts to the area, and we had to provide additional testimony on the positive critera of allowing us to operate.

Recipe approvals aside, it sounds like an interesting experiment. My first question isn't around whether or not you can ferment it, you'll be able to ferment it, the question is whether or not it will be worth your time once you've factored in the total cost. You'll need to understand the yield very well, and I'm not sold on whether or not it's economical, even if it's free. Second issue is fat content, you are talking about a serious amount of fat. Generally this isn't an issue in the distillery, this may be an expensive issue when dealing with wastewater. Realistically, will you need grease traps to deal with the waste? Third, what kind of volumes are you talking about there, 100 pounds a week? 1,000? Again, this is going to factor into whether or not we're talking about viable business or fun experiment. I'd say at a minimum from a process perspective, heat, agitate, adjust pH, use both an Alpha Amylase and a Glucoamylase enzyme to try to break down additional fermentables from the carbohydrates. At that point you'll be able to run a few trials to determine the yield. I strongly suspect you will not be able to easily measure the gravity post "mashing", due to everything else in the mix. Read up on the history of Kvas, Kvass, or Kwas Chlebowy for some insight into a potential process. This was common in Eastern Europe.

What's with the nutrient regimen? I'm curious since that's probably the most I've ever seen dosed. What's your yeast pitch rate, what's your pitch temperature, what's your fermentation temp, what's your pH at pitch?

Check with your local sewerage authority as well, they will typically have limits on pH and temp as well.

Schedule 40 PVC really starts to lose structural rigidity above 140F. I suspect if the piping was embedded in concrete, you wouldn't necessarily notice it readily.

What do you recommend for steam filtration and separation when talking direct contact? I'd always thought that the price tag on culinary steam filters and separators (any any associated steam trim) was very expensive to buy, as well as to maintain - since the filters are considered a consumable. Also, if any additive ever touched your boiler or piping, is the approach is even possible?

I did not sleep in a Holiday Inn Express last night. If the overall system was able to achieve a 75% efficiency rate, which would be very impressive, you'd be looking at 1.2 million BTU gas burner to get you a 45 minute heat up, so figure a margin of safety of 20%, 1.5 million btu? To hell with the coil, I want to hear about your hot oil heater. Commercial hot oil (HX Fluid) heaters are significantly more expensive than more common steam boilers. Keep in mind that at the temps you mention above, your HX may be flammable if exposed to an ignition source. To pump the fluid through the roughly 200 feet of 2" piping (160 feet in the HX, and to and from the heater), you'll be generating some serious pressure on the output of the pump, as well as having to maintain some serious flow rates. God help anyone that might be standing near a copper pipe if it were to burst due to damage sustained from the kinds of thermal stresses we're talking about here. Being doused with 400-500F degree oil would be a fate far, far worse than death. Don't get me wrong, I'm not saying steam isn't without risk at the scale we're talking about, but the engineering of process steam is readily understood all around the world. New South Wales? Why don't you talk to the guys over at Stilldragon Australia. I just took delivery of a 1000 liter steam jacket boiler that's absolutely beautiful, 12" bolt flange at the top to mount whatever you'd like, insulated jacket for higher efficiency, even an explosion proof agitator. I hear they are now offering jacketed still boilers near 4000 liters total capacity, and the price is going to be very very hard to beat. I could see you spending more money on your proposed setup, or even a used Lee kettle than one of these, which would be nearly ready to run.

I don't have one, but meaning to buy one, the RKI PS-2 looks like a very reasonably priced solution for vapor detection and alarm.

Don't know if you have one or not, but subdividing mortgaged properties can be a big challenge. It may require multiple mortgages or a restructure of the existing mortgage with cash-in to reflect the reduced collateral on the property that retained the residence. Also check with your local zoning to understand if the subdivision/lease arrangement will be acceptable in your current zone. They may require you to seek additional variances if not.

Depends on the nature of the bad batch. In the example you mention, technically you could still distill, recover alcohol and other volatiles, destroy the alcohol, and then dispose of stillage as normal. Just let them know that you would probably be out of business before it ever became a major problem for them.

Oops, typo - "Theoretically you *could* design a system where the liquid needed to load the trays exceeds the volume of alcohol in the boiler." Not that you would want to, but you could.

Generally there are fewer risks associated with oversizing a column than there are undersizing. However the risk associated with oversizing column diameter is the liquid loading capacity of each plate. Theoretically, you design a system where the liquid needed to load the trays exceeds the volume of alcohol in the boiler. Diameter is more directly related to the power input into the boiler than the liquid capacity of the boiler. The higher the power input, the faster the potential vapor speed through the column. Evaporation is very different from boiling, once you hit the boiling point of the liquid, the surface area is largely irrelevant. Boiler geometry is only important when we're talking about jacketed heat transfer into it.

In an equipment failure situation, hot vapor will go straight up.

The problem is what you are pumping, not how much of it. Positive displacement pumps, double diaphragm, flexible impeller, screw pumps, etc. These will all work, but the cost will be astronomical when compared to the volume you are moving, and they will have flow rates geared more towards 500 gallons, and not 55. Why not elevate your mash tank and fermenters and bucket brigade your liquids? It's sanitary, it's fast, and it's going to be hard to argue with the price, especially once you add hoses to the mix. I'm not joking, it's going to be hard to beat this. Adding the hot temperature to the mix only makes this a harder problem to solve for, since now you are restricted with what pump materials can handle near 100c. Otherwise, the most budget-conscious alternative is going to be looking for a double diaphragm pump with the largest solids capacity you can find (look at specs of all the manufacturers). I'll tell you though, in many cases you need to get to 1.5" before you can pass anything reasonable. You could probably get by with a 1" pump, but only if you take your grain down to flour. This is also less than ideal from a sanitary perspective, since you'll most likely have threaded fittings. Buckets are easier to clean and sanitize than pumps, unless you are planning to CIP your hoses and pumps for 55g. Another option is to find a cheap Walkie/Pallet Stacker, it'll let you lift and move your tanks around, and you can just use gravity to drain. As a benefit, you get a new tool to help you move pallets and grain around too.

Wondering the same, we've got an Armstrong 3033 hose station, it's got a nice thermostatic valve and dial so you can see your temp right at the station. It also has a really nice rubberized spray gun to protect your hand from the heat. The included literature says it's good to 185F. I've seen recommendations of anywhere between 140 and 180. I've seen references to some FDA and USDA guidelines for 180F, but they appear to be geared towards dairy and meat processing, where sanitizing the surface is required, but can find no reference for what the recommendation is for general washdown. I've also seen recommendations to stay away from 180F if you are just doing general cleaning, since you'll cook on proteins and just make more work for yourself. Not to mention standard PVC plumbing is only rated to around 140F. Given that safety guidelines say you'll give yourself a 3rd degree burn with 5 seconds exposure at 140F, I wager that's plenty hot enough, if you can even get to that. If you are going tankless, make sure you check your max temp, most residential units will not let you set above 120F, it may take a commercial unit to allow you to override higher. Also, figure out your max flow rate in GPM, and check the curves of the tankless unit to see what the maximum temperature rise is for your flow rate. If your water is really cold, and you have a high flow rate, you may not be able to even get anywhere near 120F, let alone higher.

Surprised your 40 gal can't keep up with the NDP-15. I have a small roller 2hp 4cfm@90psi finish nailer compressor that seems to do a respectable job on my similarly sized ARO 1/2" pump. It doesn't push it to 13gpm, but gets it more than halfway there for sure. The one thing about running these things slow is that the pulsation is wicked, so I've been keeping my eye out for a small sanitary pulsation dampener. I'm sure running it at full speed probably smooths things out a bit too. We ultimately decided to just bite the bullet on a positive displacement pump for moving mash, a deal presented itself on a pump that couldn't be passed up, so now we've got a 300 pound monster that could probably pump oatmeal or peanut butter if we needed it to. The pump head and drive are Viking, amazed at the build quality, it's like a swiss watch on the inside, the motor is a 3hp Siemens explosion proof. I believe it's a touch bigger than a Waukesha U60, but geared to run about half speed with a smaller motor.

Few, if any. Drop me a line and we can talk, my architect and attorney were both quick learners, North Jersey.