Normally it would be pointless drying onions as by careful storage of good keeping varieties it is possible to have onions nearly the whole year round and on occasion all the way through from one harvest to the next.
There are times when it does make sense to dry onions. If you have ‘bull-necked’ onions, that is onions with a thick neck, these will not keep well. So, to avoid wastage, better to dry or freeze them.
Dried onions can go straight in to soups, stews and most slow cooked recipes as they will have time to dehydrate as part of the cooking process.
The instructions below assume you are oven-drying but dehydrators are available very cheaply nowadays and in warmer climates, solar dryers are a good option.
How to Dry Onions
- Use medium to large onions. Peel and cut them into ¼” (5mm) slices.
- Separate the slices into rings – the very small centres are difficult to dry satisfactorily so its best to use them up for cooking fresh.
- Dip the onions rings into boiling water for about 30 seconds, drain and pat dry with kitchen roll. A blanching basket is useful for this or drop them into the water in a sieve.
- Spread the onion rings onto trays and dry at a temperature not higher than 65°C/150°F/Gas Mark 0 until they are crisp and dry. (This will take about 3-4 hours). One trick to keep the oven temperature this low is to leave the door open but take care with children and pets about this.
- Once cooled, pack into bottles or jars with airtight lids. Store in a dry, dark place.
- When required, soak them in warm water for about 30 minutes. If they are to be fried or grilled, pat them dry with kitchen roll.