Preserving Our Surplus Tomatos

That Westfalia dehydrator looks very good indeed for the price.
My only critical/objective comments >

The trays are smaller therefore you need a larger stack to dry the same amount (compared with a Stockli) and this means that you have to spend more time rotating the trays i.e. moving bottom tray to top every hour or so to ensure even drying. (stuff on the bottom dries faster than the stuff on top).

There doesn't appear to be a way of regulating temperature. Now depending on what you want to preserve this may not be important as the most common garden produce is dried at a fairly high 70C. But if you want to dry herbs they are best at 40C and mushrooms at 50C.

Kristen - that's a very good point regarding heat-exchange, but the idea is to get rid of moisture and recirculating the moisture laden warm air would add to the drying time. Could be done but I think you'd need more than a simple fan and heater and it would vastly increase costs ansd size.

JWK - Drying in an oven works - we did it a couple of years ago, but it takes ages and probably more power too.

 

"the idea is to get rid of moisture and recirculating the moisture laden warm air would add to the drying time"

Indeed, but a heat exchanger should exchange the heat, but not mix or reuse the air!

Imagine two pipes side by side with the exhaust pipe next to the inlet pipe. The wall between them gets warmed by the exhaust, and this heat is transferred to the inlet air.

Now make the pipes very small, and have lots of them, maybe with fins - like a car radiator - and the job's a goodun.

Sorry if I'm teaching Granny to suck eggs ...

Yes would add cost, but the designs don't even allow for this as an option, so I don't reckon they have even given it any thought - or the cost is horrific maybe :(

Good points about the size of the trays, I hadn't spotted that.

 

Yes, grandad's sucking eggs.:D
I ought to have read your original post more carefully as I interpreted it as a suggestion just to recirculate the warm air. I do understand heat exchange - latent heat/evaporation etc.
As for costs - it probably would be viable on a commercial scale, but for a small domestic unit I'd guess it would at the very least double costs.

 

What a fantastic thread extremely helpful. Shame my gardens not produced enough veg to store :( Maybe next year I'll be having a glut like Freddy :D

 

Wrists-duly-slapped, thanks John!!

I haven't used it on the Tomatoes - forgot that was why I got it :( I'll try some tonight.

I have used it on LOTS of apples. They are brill - the dried frtuis provide an explosion of taste rather like Opel Fruits did (or whatever they are now called - something beginning with S I think??)

It takes quite a long time - I leave it on overnight on the cheap rate; the on/off switch is mechanical (so it would work fine with any el-cheapo timer), there is no temperature adjustment, and shuffling the trays from top-to-bottom helps (the ones furthest from the hot air get all the humid air from the other trays, so take longer to dry).

Also going to try drying my chillies

Raspberries were a disaster. Didn't really dry much, even after 8 hours, so I was just left with a gooey mess :(

Recommended, and probably worth getting a more sophisticated model. I was disappointed that I couldn't find any (domestic) model that had any sort of heat-exchanger - outrageous that it electrically heats the air, and then "throws it away" - particularly as on this model the hot air inlet, and exhaust, are right next to each other.

I'm contemplating adding something to the solar-panels I'm planning to install - so that when there is excess solar-hot-water-heat I can dry fruit / veg cheaply - just need a fan.

 

"Solar panels to dry fruit? - another project coming on I feel."

Should only need a radiator (car radiator??) and a fan, plus some trays, surely ??

 

Superb thread. Thanx to all.
John

 

I dried my chilli crop the other day. Worked extremely well. I had a [dried] chilli on my supper last night; I was expecting to have to chop it up, but I could crumble it between my fingers - shouldn't have rubbed my nose though :D

 

"Seems your drier works really well"

It certainly works! However, I would emphasise the points I made earlier:

Mine was very cheap, relatively.

It runs for 7 or 8 hours to do its job. I don't know how much Leccy it uses, but there isn't much subtleness to it!

I think something with variable temperature. plus a timer, would be better. (For me it is important that there is a Start time, as well as Duration, so I can use it on Economy-7, key part of my buying decision was to have a mechanical switch, rather than a electronic switch, so I could use it with a conventional Start/Stop timer. It might be that the more expensive models, with a "duration timer" might not work with an external timer to start them at Midnight - i.e. if their timers are electronic.)

There is an issue that the trays furthest from the heat take longest to dry (they get moist air from the trays nearer the heat, obviously). So you either need to be around to shuffle the trays, or buy a horizontal configuration drier (hot air supplied to all trays at the same time - in parallel), rather than a vertical one (hot air passes through each tray in series)

And the absence of a heat-exchanged to "reuse" the heat (but without the moistness of the air) offends my new-found green credentials!

 

Thanks for the reminder K. could be very useful
robert

 

Just been reading posts on tomatoes very interesting. Im going to throw another one into the pot. Cooked dressings or or purees. Put tomatoes (or peppers these work really well) in a pan with roughly chopped onions and garlic quantities depend on taste but dont be shy with them salt and pepper and half cover with olive oil and a little white wine if required (not critical if you dont have abottle open) boil for about 5 mins longer for peppers these have to be soft. then blitz with ahand blitzer while still warm in the pan.

freezes really well and can be used as base for all number of dishes from salad dressings to fish sauces pasta and pizza topping bases. just anote when cooking with olive oil always use blended dont use virgin or extra virgin.

 

Just read this thread and found it fascinating ,googled dehydrators and found them and the price :lollol:. I mentioned to my O.H. what a useful investment, and his response was, not another must have electric item to keep in the cupboard.

I thought there must be another way, so heres a link to a page i found which seems to give a general picture for drying,

As i don`t have huge huge quantities of surplus produce it seems a more reasonable way to go
www.bbc.co.uk/dna/h2g2/A963461