What is Freeze Dried Coffee?

Although nobody would pretend that instant freeze dried coffee tastes as good as freshly prepared coffee from the bean there is no doubt it has a large market, both commercially and in the home.

It's sheer convenience and ease of use is probably its main advantage and with the improvements of modern production processes the flavour of the final beverage has improved dramatically. Just add a spoonful of freeze dried coffee granules to a mug, add hot water and you can enjoy a decent cup of coffee.

We have all probably drunk freeze dried coffee at some stage, but what actually is it and how is it made?

Initially fresh brew coffee is made in the usual way using a very large industrial bulk brewer in which very hot water is passed though fresh coffee grounds in a filter system to produce the hot coffee liquor we are all familiar with.

This coffee liquor is then concentrated through a series of evaporators under vacuum where some of the aroma and flavour compounds are also removed and stored. This ensures that some of the flavour and aroma of the coffee that is lost during the freeze drying process can be 'put-back' into the final product just before packing.

The concentrated coffee liquor then moves on to the actual freeze-dry processing equipment. Here the coffee liquor is initially foamed and then frozen to a temperature of -450 degrees centigrade. It is then ground to the required particle size.

The ice crystals that formed in the freezing process from the water content in the beverage are then removed in a process called sublimation. Here the frozen granules are subjected to a high vacuum which results in much of the water ice content to be transformed directly into gas (without a liquid stage it would normally undergo) before being returned to room temperature.
The finished product usually contains between 3 and 5 percent water. The more volatile flavour and aroma compounds extracted at the initial brewing stage are then returned to the dried product just before packing.

A large quantity of used coffee grounds are produced at a typical freeze dried coffee factory during the process but these are put to good use. They are usually sold on as animal feed, compost or organic fuel.

Freeze dried coffee is considered to be of superior quality to spray dried coffee which is made by a different process. The industrial production of spray dried coffee will be outlined in another article.

Make the Most of Mushrooms

by Dyfed Lloyd Evans

Mushrooms are an amazing foodstuff, neither plant nor animal but a whole kingdom of life all their own. Though many mushrooms are cultivated the vast majority can only be found in the wild. Here you find recipes for both wild and cultured mushrooms so that you can know how to get the best out of them.

They come in a wide variety of textures, colours and flavours -- from the tough and meaty to the subtle and innocuous and can be used to flavour a dish or simply to add substance and texture to it.

These days you can easily buy a whole range of dried or fresh mushrooms in your local store, but an experienced forager can source an almost year-round supply in their own back yard.
Mushrooms are truly versatile and can be used in an amazing array of dishes. Often various mushroom types can be substituted for meat in just about any dish. Indeed, the Romans and Greeks used them for this very purpose. But, in general, fresh mushrooms do not last long and they become soggy and inedible very quickly. The good news, though is that mushrooms can be preserved quite quickly. If you have mushrooms that are past their best then they can be strung on a string and hung in a warm, dry, spot to dry. Or they can be pickled. Another way of storing is to chop and to fry with onion garlic and herbs to make what the French call a 'duxelle'.

Mushrooms fried in this way can be stored by freezing and then can be added to soups, stews or any dish calling for fried mushrooms.

Below you will find two classic mushroom-based dishes. The first incorporating a farmed or shop-bought mushroom and the second incorporating a wild mushroom.

Mushroom and Spinach Rustic Pie

Ingredients:

125g unsalted butter


350g plain flour
Salt


25g parmesan cheese
egg yolk
water


250g spinach


25g butter
large onion, chopped


75g oyster mushroom


4 skinned, chopped, plum tomatoes


125g diced mozzarella
salt and pepper


3 eggs, beaten

Method:Rub 125g unsalted butter into 350g plain flour with a pinch of salt to make a fine crumb texture. Stir-in 25g of grated parmesan cheese and then add an egg yolk and enough cold water to mix to a dough. Knead lightly and chill the pastry for 30 minutes.

Meanwhile wash 250g spinach and cook for 1-2 minutes until just wilted. Drain well and then roughly chop. In a frying pan, melt 25g butter, adding a chopped large onion. Cook until soft and golden. Add this to the same bowl as the spinach, mixing in 75g of a well-textured mushroom such as oyster mushrooms, porcini or chanterelles. Add four skinned, chopped plum tomatoes, 125g diced mozzarella cheese, salt, pepper and three large beaten eggs. Mix together well, then trim 2/3 of the pastry, rolling out in preparation to line a 23cm-deep quiche tin. Trim the edges, and dampen with water, spooning-in the filling. Roll out the remaining pastry, and cover the top, pinching the edges together to seal. Brush the top with a little beaten egg and bake in a pre-heated oven at 200°C for 25 minutes, or until golden.

Method:Rub 125g unsalted butter into 350g plain flour with a pinch of salt to make a fine crumb texture. Stir-in 25g of grated parmesan cheese and then add an egg yolk and enough cold water to mix to a dough. Knead lightly and chill the pastry for 30 minutes.

Serve hot or cold.