I have already done a book review, on this solidly useful book, I still find myself reaching for it at least once or twice a week to check my temps for what I am preparing for the dryer.
However I was able to take a seminar with one of the authors and thought I would do a round two and touch on some of the things he talked about.
“Food drying is something everyone tries at least once but rarely do it well.”
The main goal regardless of what you are drying is working to that magical sweet spot of getting your foods down to 10 percent of their wet weight, but as most folks are not going to do the math, the experts have taken that to explain we are looking for a leathery feel with some flexiblity.
According to him, if you are wanting to bring juice out of berries to then added and use in your leathers, freeze them first before simmering them, that you will get a better, higher yield in regards to the juice vs the fiber, this is interesting, and the other would be the case for drying. If you want to make a berry paste, freezing will therefore remove more juice, and allow you to dry your fruit leathers faster.
He says the hardest thing to dry is the Tomato as it’s typically 95% water, roma’s are typically 92% water, where apples are 84%.
Always be flexible, while it’s worth writing down what worked last year, it won’t be the same this year, according to him, each season is different, as everything you are working with will have different weights, thicker or thinner skins due to the changes in growing season to growing season, so something that worked last year at seven hour, might take six or eight this year.
If you are in a market for a dryer, he recommends that you look for one that will blow the heated air ACROSS in the airflow, not the Top or Bottom Airflows.
Higher temp are not better, as once you cross over that 50 to 55c line (which many dryers will do) you are looking at Nutritional degradation. Also the higher the temp, the more likely you are to be baking them, rather then drying them, the higher temps used in drying in a regular oven or in a improperly made solar oven is the fact that you don’t get enough air movement, and create a stagnant boundry layer. Getting solar fans to make sure you are having the correct air movement in your solar dryer is critical.
If you have improper high heat or a stagnant boundry layer, then you are looking at Case Hardening, which in a nut shell, means that by either of the ones listed above, you have created a hard outer shell that prevents or restricts moisture from leaving.
Solar dryers: We are in a good area in regards to the amount of daylight, however most commonly built solar dryers take good air movment, and have a hard time with temp control, highly recommends you have one or two built in solar fans in your homemade solar dryers.
If possible use stainless steel baking racks from old ovens as the main racks, then get 1/4 inches plastic mesh, if you are drying in larger amount for critter feed, then you can move over to steel window mesh for reasonable prices and large space. For indoor dryers, he says that plastic needle point canvas cut to fit, works very well.
Herbs should never been done higher then 45c, and if you walk in and it fills your whole house with lovely smells, it’s too high, reduce your heat. Example given was mint, if you dry your mint too high, the house will smell wonderful but the tea won’t taste much like mint because you have released most of the oils in the drying process instead of saving them.
Ideally you should have no more smell in the dryer than if you hanged to dry the herbs by air if at all possible.
Over and over, this was the key message: Longer times and slower temps will give you the best result!