The best time to freeze ginger or make Ginger or Ginger-Garlic Paste is Late Summer or Early to Mid Autumn. Ginger and garlic are plentiful then, good quality, local and cheap. You can often get young ginger at this time – it is gentler in flavour and delicious.
A good strategy for Autumn is to make a couple of jars of Garlic Paste and Ginger Paste (or Ginger-Garlic Paste), freeze 1 or 2 kgs of garlic, broken into cloves, to supplement the paste, and freeze some ginger root. Adjust the amounts to suit your family’s consumption of garlic and garlic.
These pastes are fairly common in parts of India, with households making it every morning. Traditionally ground by hand, it is now most commonly ground in electric wet-dry grinders.
Outside of India it is made in the food processor or spice grinder, but the texture is a little different. It keeps well in the fridge and much longer in the freezer, so make some when garlic and ginger are at their peak of quality and are cheapest in price. Grind with salt, and sometimes I add a little vinegar to boost the preservation qualities.
You can make ginger, garlic, ginger-garlic and chilli pastes the same way. Ditto turmeric and galangal pastes.
For longer lasting paste, avoid any use of water. My trick is to take whole cloves of garlic and roughly chopped ginger and break it down with my hand-held immersion blender. Then I transfer it to the small processor in two batches to produce a nice creamy paste without any water.
There is some concern about the safety of storing garlic. Please do your research and make up your own mind. Keep all pastes refrigerated at all times. You can also freeze any paste that you are not going to use quickly. It is good to freeze it in icecube trays, then store the cubes in ziplock bags. The cubes are conveniently sized for adding to dishes.