The short answer is no, they are not. To determine if HDPE plastic is permeable there are two things to consider; the thickness of the plastic and pressure. The outside air pressure is not enough pressure for air to pass through the walls of the tank to the inside. From the inside, one could create enough pressure. However, the tank would probably burst. A thin walled tank may breathe like a wood cask. Since our tanks are a full 5/16 of an inch in thickness, this doesn’t happen. At this thickness they will not breathe. Permeability is not a risk with Minibrew tanks and fermenters. This information comes from the plastic manufacturer.

Of course, everything scratches…. including stainless steel. Our HDPE has a thin layer of plastic that can be penetrated with a sharp knife. If this happens to your tank the problem can be easily solved. You can use a dull knife to reduce the sides of the scratch. You can also use a small propane torch and slowly brush the flame over the scratch. The fuzzy hairs will burn off and the plastic will melt and fill the void. Just be careful not to burn the plastic. The other option is to ignore it and definitely sterilize with very hot water (180 degrees) the next time you brew. Leave those expensive stainless steel spoons to the other guys. Always use plastic or wooden implements when stirring your fermenter or mash tun. There is no reason to scratch food grade HDPE plastic. Teflon frying pan coating has been around for a long time. The secret is the same for our tanks. Use a wooden or plastic stirring implement and a Teflon scouring pad. This thin layer is much like the layer on stainless steel. However, the healing process on stainless steel is more complicated and is a process of oxidation. When the outside layer of stainless steel is penetrated your tank may rust. You can scratch stainless steel if one is not careful. I bet the old brewer’s years ago, had the same problem with copper.

The answer is yes! The plastic used for our Minibrew tanks is certified by the FDA as food grade. If HDPE plastic was not pure hospitals, researcher laboratories and everyone else that needs a sterile environment would not choose HDPE.

Number 1: The collection ball only holds 23.7 ounces of liquid. A good flocculation may be two or three times that amount.

Number 2: When the collection cup is replaced, air in the ball bubbles up through the wort. The air may be contaminated, infecting your wort and ruin your beer. I like to call it a bacteria ball. If anyone can find a major brewery using a collection ball please let me know. I have looked and so far can't find one using the ball or any container to collect the dead yeast.

Number 3: The 60 degree cone is the ideal slope so all the dead yeast cells slide down to the apex of the cone. (University of California Davis Brewing School study) When the bottom valve is opened the collection ball restricts the flow and less of the dead yeast escapes. With the Minibrew fermenters the force of the liquid above washes out more of the yeast unrestricted into a container held

below the valve. Don’t be concerned, there will always be some left. This is why most commercial US brews filter their beer.

Our Minibrew fermenters have a racking port approximately 9 inches from the apex so the finished beer can be racked (transferred to bottles or kegs) without disturbing any yeast that may be left below in the fermenter. This valve is also a convenient way to taste your brew in progress and for specific gravity testing.

About 10 to 15 percent of the yeast washed out the bottom may be alive. This yeast can be saved and reused. As the yeast washes out, watch the color change. When it turns lighter close the valve. The lighter yeast is alive. I use a coffee scoop and pass it through the flow just before I close the valve. This small amount of yeast is all you need to make a starter. However, you will need to add oxygen and some food to build enough volume for a starter. You may want your club to pitch in and buy a microscope. This way you can check your starter for bad bacteria.

Our tanks are easy to clean and sterilize. All popular cleaning and sterilizing agents can be used on our plastic fermenters. They will not harm the inert plastic material. Another method I use is hot water heated to 180 degrees. The heat will sink into the plastic and all parts, killing any bacteria. This procedure also works great with stainless. I can’t mention this enough. Please use only Teflon scouring pads when cleaning your fermenter.

There are three kinds of threads that can be used in our HDPE fermenters and brewing tanks. They are HDPE plastic threads welded into the tank, stainless steel inserts where the tank is molded around the inserts and there are bulkhead fittings. We investigated all three types when we started our business in 1997. We found the stainless insert will come loose over time from the heavy valves and pipes connected to the tank. This puts too much weight on the stainless inserts. Also, over tightening will loosen the inserts. Bulkhead fittings are easy to replace and therefore work best. They are designed to seal on a flat surface and they are also expensive. We opted for the plastic fittings welded into the tanks. We provide a plastic nipple, which is a short threaded pipe. That was in the beginning. We have since converted all our tanks to our own specially designed Easy Seal Weldless Bulkhead fitting. Now the stainless steel valves are screwed into SS nipples which screw into the Easy Seal fittings. Nothing breaks and you still have the advantage of HDPE. Stripped threads are a thing of the past.

There is no need to transfer to a secondary vessel. It is less work and safer to remove the dead yeast cells from the bottom while you leave the fermentation process above untouched. Think about it! How many small batch brewers go to great effort to transfer almost finished beer or wine from one carboy to another so the finish product is not sitting on dead yeast cells? It takes less effort and is less risky from an infection point of view, to remove the small volume of junk that has settled to the bottom than it is to siphon the whole batch to another vessel. Sometimes your brew will produce a large amount of dead yeast or it can become stuck at the dump valve. This is why we recommend a small pan or container for catching the dead yeast. Enclosing the bottom valve with a collection cup limits the amount of dead yeast you can remove and blocks you from breaking up the stuck accumulation. If you are using a cup as our competitor suggests, you potentially will contaminate the wort. This is because as you replace the cup, air bubbles up through the wort exposing the wort to bad bacteria and infection. I wouldn’t take the risk and ruin my beer. We recommend rinsing the outside end of the valves with a diluted solution of bleach before opening the valve and after closing. We recommend removing the trub daily to prevent off flavors and touse the extra liquid to measure specific gravity. You might even sneak a taste. Wine does not produce as much dead yeast and may only require removal less often. Eliminating the secondary transfer is only one of the reasons for the conical design. If you are crushing grapes, a second container may be required.

The precise shape of the 60 degree cone and top cylinder (one unit wide by one unit high plus) is a fermenter design that has been perfected over the years. Without the cylinder on top and the 60 degree cone on the bottom one does not have a cylindro-conical system; these perfections were developed over many, many years by dedicated brewers looking to improve taste, consistency and ease of use. The shape positions the yeast and convection does the rest. The mixing motion of the currents assures complete yeast wort/wine contact. As the yeast approaches the cool sides it sinks and as it hits the conical shape it is forced into the center as it slide down. Tests have proven the 60 degree angle is the perfect angle for more yeast to slide to the apex of the cone. Active yeast gives off heat. The hard working warmer cells rise to the top and spread to the sides to complete the cycle. Dead yeast cells will drop to the bottom of the conical for removal.

The Minibrew System brand of fermenters have thermometer threads located near the middle of the liquid for precise temperature monitoring (not available on the Minibrew Mini Me model - the 6.5 gallon conical fermenter). A screw-in plug is included with the purchase. See the parts page for a complete description of our thermometer.

We believe open fermentation is best. We believe closed fermentation puts pressure on the live yeast cells even with an airlock. Our fermenters are the next best thing to open fermentation. Because of the way the lid fits onto the tank it makes it almost impossible for bacteria to settle into the wort. As CO2 builds up to the top it moves to the edge, then goes down and out around the bottom of the lid. For bacteria to move into the fermenter it must go up against the outflow of CO2 then over and down into the wort. This system works and also helps start the convection currents necessary for a more complete ferment. That said, we do provide a lid sealing gasket if you feel the need. It is the blue gasket on our web page. The old red gasket is no longer available.

Yes! The 1/2 inch racking port threads are located on the side of the cone, just above the settled yeast level. The racking port valve is for sampling, specific gravity testing and racking to bottles or kegs. The valve at the apex of the cone is for filling the fermenter and draining dead yeast. The thickest of yeast will flow through our large one inch valve. All valves are made from lead free brass. There is no concern about lead leaching into your beer or wine. All this is without lifting a carboy, siphoning risk or breaking glass. (I dropped a carboy in the kitchen sink once. It broke the carboy and put a big dent in the sink.) Now small batch brewing is easy and professional. Carboys, plastic buckets, converted kegs and stainless steel are history. They just do not provide the benefits such as ease of use an affordability.

We always aim for make sure our customers love our products, but if you do need to return an order, we’re happy to help. Just email us directly and we’ll take you through the process.