Wednesday 16 February 2011

All Grain/Full Mash Brewing

All Grain Brewing: Overview

This is where the flexiblity of brewing really begins. The process starts by taking the the fresh crushed malted grains and extracting the natural fermentable sugars. All grain brewing does, however, require more equipment and time although the benefits will be plain to see. The crushed grains are soaked for a period of time in a Mash Tun to extract the sugars. The grains are then rinsed to ensure that the maximum amount of sugars have been released after which the wort produced is then boiled for a length of time (usually about 90 minutes). During the boiling process hops are added. At the start of the boil, bittering hops are added and at the end of the boil aroma hops are added. The wort is then cooled and added to the fermenter where the process is exactly the same as fermenting beer kits.

The benefits to All Grain brewing is the ability to have strict control over the recipes and ingredients therefore giving you the ability to formulate your own recipes.


Another consideration of starting All Grain brewing is space. The actual brewing area needed can be small and have seen many home brew setups based on a three tier shelving unit no more than a metre square in area. One of the bi-products of this type of brewing is steam and the brew smell and if done inside the house could make you unpopular with the other half ! I tend to brew outdoors, the only draw back being the stability of the weather - particularly in the UK. The other drawback to brewing outdoors is the possible contamination of the brew particularly when it is being cooled prior to fermentation. Care must be taken to cover the wort during cooling as much as possible.

Let's Make Beer: All Grain Brewing

Preparation of the Ingredients

It is important to have a pre-conceived recipe from the start. The first step, enuring that you have cleaned your equipment, is to weigh out all the ingredients ready for adding to the mash tun. (You may want to get your water to temperature in your boiler while doing this.) Your grains should be milled if you have bought them whole by passing them through a grain mill. Note though that certain cereals and grains need not be crushed or mashed. These include cereal adjuncts such as torrified wheat, flaked barley. Roasted barley can be added directly to your boiler or mashed just as with chocolate malt and black malt. Chocolate malt and Black malt are used for both flavouring and colouring in beers. They produce a rich dark colour ideal for milds, porters and stouts.

Mashing

Heat up your water in the boiler to 73°C (This is slightly higher than our aimed mash temperature of 67°C as when the strike water hits the grains it will slightly cool.) Add a quantity of the prepared grains to the mash tun and add enough of the strike water to soak the grains. Gently mix this with a brewers paddle to ensure their are no dry pockets in the grains. Add more grains and repeat until all the ingredients are in the mash tun. The amount of water required for mashing is usually 2.3 litres of water to every kilo of grain. Although this is not overly scientific as certain grain absorb more water it seems to work. Check the temperature before you have filled the tun with the required amount of water. If the temperature has dropped below the required temperature for mashing you may need to add some hotter water.

Cover your mash tun with its lid and as a precaution place some towels over the lid to create extra insulation then leave for the full mash time - usually 90 minutes.

After 90 minutes has passed check the temperature of the mash tun. (Don't do this during mashing as removing the lid will cause the temperature to drop.) Keeping notes on temperatures can aid future brewing ventures and at this stage will also rate the efficiency of your mash tun - does it require more insulation ?

Connect a piece of tubing to the tap on the mash tun and start to drain the wort into a plastic kitchen jug. Do not drain the tun to vigorously as this may cause blockages to occur and break the grain bed. The first few drawings from the mash tun will be cloudy and contain numerous bits. This needs to be returned to the mash tun for refiltering through the mash bed. When the wort is draining clear transfer the draining tube into a large bucket or your fermenting bin.

When adding the first drawings back to the mash tun be careful not to disturb the grain bed as this will cause blockages. A simple tip is to use a light plastic plate or plastic lid with holes drilled into it that can rest on top of the grains.

Once the mash tun has been emptied it is time to sparge.

Sparging

Sparging is the technical term for rinsing the sugars from the grains remaining in the mash tun. The usual method is to add hot water gently over the grains while draining off the collected water from the mash tun outlet. This is commonly referred to as Fly Sparging. Sparging devices are available from your home brew shop or alternatively something like a watering can can be used to evenly distribute the hot water. It is important to control the flow of the sparge water so as not to upset the grain bed. The grain bed left by your initial mashing should act like a natural filter.

Another process commonly used is Batch Sparging. This is an easier method than fly sparging and one that I intend to try (I have always used fly-sparging by force of habit). A good and well written resource can be found at the Bay Area Mashers website.


Boiling

Once the correct amount of wort has been collected it is time for the boil. Pour the wort into the boiler and heat until you achieve a good rolling boil. You will need to watch out for any boil overs throughout this stage. They are most likely to occur when the wort reaches the boil point for the first time, when hops are added and when protofloc tablets etc. are added. Once the boil has been achieved after 15 minutes (or as specified by your recipe) it is time to add the required bittering hops. Towards the end of the boil it is then time to add your required aroma hops. The boil time usually lasts for 90 minutes. Again, in the last few minutes of the boil it is time to add your finings (Irish Moss, Whirfloc etc.) to coagulate the unwanted proteins in the mix. You will see the proteins clump together almost immediately.

Wort Cooling

In the last few minutes of the boil, if you are using a copper immersion heater, you will need to place your cooler into the wort. Assuming that you have cleaned the cooler prior to immersion, the boiling wort will naturally sterilise it. Turn off the boil and start the water flowing through your cooler. The cooling process usually takes 20-30 minutes.

Once the wort has cooled to approximately 30°C you will need to run the wort from your boiler to your sterilised fermenter. By placing a sieve on top of your fermenter you can remove any unwanted sediment that may come from the boiler and also aerate the wort ready for yeast pitching.

It is now time to follow the fermentation process.

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