Our customers who use airlock caps often ask us when to change the airlock cap for the storage cap, and when to remove the dunker (weight) from the jar. These are important questions, both because you want the fermentation process to be smooth, but also because you really want to get the airlock lid and the dunker back into use again as soon as possible!
Each Fermenta Lock cap is packaged with a storage cap – so the airlock cap can be switched for the storage cap when the ferment no longer requires venting. Each Fermenta Dunk weight comes with an extender – a plastic disk that is sized for the inside of the jar. Since the weight must be small enough to fit inside the jar opening, it is not large enough to reach the edges. The Extender goes all the way to the edges, and the weight is placed on top of it to hold the food down.
Lacto-fermented foods are LIVING FOODS. This means that the food continues to change and age until it finally spoils. Fermentation delays the point of spoilage by many months – anywhere between 6 and 20 months, depending on the food, the brine strength, the temperature, handling methods, etc. Living foods eventually spoil. This is part of the cycle of health and life. But it also means that during the time when it is healthy and good, it is in a state of constant change. This change is rapid at first, then slower, and finally very slow. The flavors and textures will gradually change over time – not in unpleasant ways, just more or less complex in most cases.
Fermented foods go through three basic stages that are observable. Each change can be responded to by a change in the fermenting process.
First: The initial startup phase. This is where the fermentation process begins. You prepare the food, pack it in salt, or salt brine, add an extender, and then a weight on top of that (several weights for kraut, which requires more weight than brined foods), and then you put the airlock cap on. You can follow this process by SMELL. As the foods inside begin to ferment and release gasses, they will start to vent through the airlock (the orange button on the Fermenta Lock Cap). When that happens, you’ll start to smell a nice pickly smell on the airlock. Once it smells like good pickles (after three to five days – usually three in the summer, five or so in the winter), the fermentation is well established, and you then move the jar to the fridge. If they are left out, especially in the heat, they are more prone to spoilage, though many people leave them out for longer periods before putting them in the fridge (foods were traditionally fermented in a root cellar, or basement, which was typically about 50 degrees, so the change was not required, but this is how we adapt to current conditions). The food can usually be consumed any time after this point, though some people are sensitive to foods that are less than a few weeks old.
Second: The active fermentation phase. After you move the jar to the fridge, the fermentation process continues, it just slows down. If you tip the jar, and bubbles still come up from between the food, it is still in the active phase. LEAVE THE AIRLOCK ON, and leave the dunker in, as long as the food is in the active phase. Once the food is no longer releasing bubbles when you tip the jar, it is entering the storage phase, and at this point, you can switch the airlock cap for a storage cap.
Third: In the storage phase (when it is no longer releasing bubbles), the food will continue to gradually change – fermentation has not stopped, it has just slowed down to an almost imperceptible sequence of changes. One of those changes is that little by little, the food stops floating quite as much. This varies between food types, some will always float some, others will sink more dramatically. Leave one or more weights (and an extender if using one) in the jar as long as the food bounces back up above the level of the brine. If you are using more than one weight, you can usually remove them one at at time over the storage time of the food. Eventually the food stays reasonably covered without the weights or extender. If a bit of the food is above the brine, it is not generally a problem. Foods can be stored for very long periods of time in this third phase, when handled correctly.
We do NOT recommend repacking foods into a smaller jar when amounts decrease!
When you repack, you introduce air through the entire ferment, potentially reducing the overall storage life. Leaving it in the original larger jar means there may be more air above the ferment, but the salt brine limits the movement of the air below the surface of the liquid. From a strictly scientific standpoint, repacking has more potential for harm than leaving it in the larger jar.
When using, remove what you need, using a clean utensil, and try not to stir up the entire jar of food. Wash the extender and dunker with clear water before replacing them if they are still needed.
We have eaten foods handled this way as long as 10 months after placing them in the fridge. Nothing has lasted longer than that – but not because of spoilage. Simply because they are always eaten sooner. The 10 month old food was crisp, tangy, and still had the squeaky feel of a reasonably fresh ferment. There were no signs of spoilage anywhere, even though the weights had long been removed, and the jar was less than half full for months before the last of it was consumed.
Many individuals want a set list of instructions, consisting of exact amounts, precise times, and specific parameters. Fermenting is as much an art as a science, and getting it right has more to do with paying attention to what the food is telling you than it does a list of instructions that have nothing to do with your specific food. There are rules. But the rules are flexible, because the process of pickling is flexible. Learn the rules, and the ferment will tell you what it needs, and when to change the conditions.