Roasting Your own Grain
Its not always possible to obtain every grain that a recipe calls for so at times you have to go with the flow and either substitute or just take the plunge and roast up some of your own !
This page briefly describes how I make AMBER MALT and ROASTED BARLEY.
I learned the Amber malt process from an article on The Brewery web site. In that article, within their library, you also learn how to make brown malt.
The origins of my roast barley process probably sit with a discussion I once had with Moritz Kallmeyer at Draymans Brewery (in Pretoria) . . . probably !
- In my process I start with pale malt.
- Layer the malt no more than 2 cm deep in a baking tray. Line the baking tray with aluminium foil so that food flavours don't attack the malt flavours.
- Remember, as the malt will lose moisture, weigh out about 5% more than you need !
- Set the oven to 100°C (212°F). Once its there pop the tray of malt in.
- Leave at 100°C (212°F) for about 30 minutes, this helps rid the malt of its residual moisture. Stir it once in the middle of the 30 minutes.
- After 30 minutes turn the oven up to 150°C (300°F) and open the oven every 15 minutes, remove a couple grains, slice them open and see what colour they are inside.
- A light cream colour is the way things start out. When it gets to a pale buff colour you have your own homemade version of amber malt.
- If the colour goes to a dark buff colour (like brown wrapping paper the article says) then you may just have some brown malt.
- Enjoy the unique smell of biscuits in your house . . . .
- Buy your barley. I simply visited the local supermarket and bought some 'pearl barley'. People often buy this for making soups with. Remember, you are making roasted barley, which means that you MUST NOT start with malted barley. If you roast a malted grain you will end up with a 'black malt' which will not be appropriate for a dry Irish stout.
- Line a baking tray with Aluminium foil to prevent food flavours from affecting your grain flavours. Preferably use a clean baking tray with no food residues burnt onto it as stirring grain in a foil lined tray is a real pain !! A 10 minute soak of the tray in hot caustic will pretty much clean it up if you're able to be careful about the caustic.
- Pour your barley grains, uncracked, into the baking tray. Remember to add about a third more than your recipe calls for because the barley grains lose a lot of weight during the roasting. I have seen 2000g of pearl barley roast down to 1500g over a 2 hour period.
- Set your oven at 230°C (450°F) and wait for it to come up to temperature. Don't be tempted to pop your grain in when the oven is cold as the timing here is VERY important and you will introduce an initial period of time at the beginning (while the oven heats up) that you will not be easily able to account for later.
- When the oven is up to temperature put the baking tray in and note the starting time.
- My experience is that after about 30 minutes you will become aware of the smell of hot barley and that, over the next period of time this will turn into a visual event as well . . . the smoke tends to pour out of the oven when the door is opened !
- One of the key things that I have learned in making my own roast barley is that, even though the outer surface of the barley grains has gone black, it may not necessarily mean that your beer will also be black ! My first ever attempt saw very black looking barley that had been roasted at 230°C for an hour or so but the first runnings from my mash tun surprised me by being rather yellow !!! Yellow Guinness I thought . . . agghhh . . .
- So, keep a careful note of your starting time and aim for a total roasting period of say 90-120 minutes. More on the time duration just now . . . it critical though so listen up !!
- Now, when the barley roasts, it will get hotter around the sides of the baking tray. This means that the barley grains at those points will actually roast quicker. You will also notice that the top layer of grains in the tray will also roast quicker than those sitting just beneath the surface. All of this has an affect that will differ in degree between different people's ovens, baking trays, grain depth, gas versus electric etc. So, you are going to have to experiment a little to get things right for your conditions.
- On the issue of 'the degree of roasting effect' you are aiming, theoretically, for all of your grains to roast by the same amount, thereby all finishing the same colour and degree of roast. However, in the real world, this is near impossible. Professionals would use a rotating oven so the grain continuously rotates. This works very well and, in fact, it was when someone adopted this approach from the coffee roasting dudes of the 18th century that brewers were first able to use highly roasted grains in their beers. The gentleman who adopted the approach actually patented his invention and all roast malt made at that time was referred to as 'patent black malt', a name that survives today !
- On the home front, if you can rig up something with your oven'srotisseriee then go for it ! However, the rest of us will need to pay particular attention to three things during roasting :-
- (i) The temperature of the oven.
- (ii) How often you stir the grain.
- (iii) How deep you make the grain bed in the baking tray
- The first of these will have a major affect on the overall degree of roasting so I would suggest, keep it simple, set it to 230°C (450°F) and don't touch it again.
- The other two will affect the 'spread of roasting effect', i.e. stir every 5 minutes and you will have a tighter spread on the colour of the grains, stir once every 20 minutes and you will have grains from charcoal black to light brown all co-existing in the baking tray at once.
- As the roasting effect appears to speed up towards the end I have adopted the following schedule :-
- In the first 30 minutes just leave it at 230°C and go have a beer.
- In the period 30-60 minutes, stir at 30, 45 and 60 minutes.
- In the period 60-90 minutes, stir every 10 minutes.
- In the period 90 minutes and over, open and stir every 5 minutes.
- Throughout, you should work to minimise the time that the oven is open, so that heat losses are minimised. I do not remove the tray, preferring instead to just open the oven door, stir and close. Please also check the disclaimer at the end concerning the safety issues.
- If this is the first time that you are roasting your own barley I would suggest a little side experiment to get some feeling for what you're doing. The idea is to make small trial infusions as you go in order to assess the colour of the grains. This consists of a glass of water at the mash strike temperature into which a measured amount of crushed grain is added.
- What I do is get a few (3-5) small glasses (say a maximum volume of one cup, 250 ml) and line them up in the kitchen. I then boil the kettle (the real kitchen one that is !) and then after about 30 minutes you open the oven and withdraw a few grains on a teaspoon. In the meantime you have added say an inch of cold water into your glass and topped this up with the boiling water in order to get water at about 70°C (158°F), i.e. in the order of mash strike temperatures. The grains should be crushed using a rolling pin and swiftly added to the glass. Over the next 5 minutes or so you will see the water start to colour. Give an occasional stir to ensure the maximum colour is extracted from the grains.
- If you have a marker pen, label the glass with the time at which the grains were removed from the oven. At 30 minutes, the water will remain pale in colour, certainly not black. By 70-80 minutes you will see a distinct reddish-brown colouring taking place. There after it will go black, depending on how far the roasting effect has proceeded. The idea is that, at some point in time, you will be happy with the colour of the mini-infusion and you can then remove the tray of grains from the oven.
- One key issue I realised was that, to be as accurate as possible, you should make sure that the amount of grain you add is in relation to the amount of water in your mini-infusion. For my dry Irish stout recipe I use 1355 g of roast barley and it ends up in myboilerr, at boil end, in 78 litres of wort. Dividing these numbers you'll see that this corresponds to about 4 g of grain in 240 ml of water. I therefore use a standard drinks glass which is around 250 ml in volume and add 4 g of roast barley grains. 4 g of roast barley grain is around 8 ml I found and corresponds to the volume of a plastic coke bottle cap, you know, the type that when you first unscrew it the collar breaks off. The volume of the cap without that collar gives you close to 4 g of roast barley grain, assuming the grains are level and not heaped into the cap. So that's how I calculated the ratio of grain to water to make sure that the mini-infusions are representative of the amount of colour dilution I will see in the real beer.
- Another key issue is the temperature of the water in the glass before the grains are added. I STRONGLY suggest that you control this carefully to be 70°C plus or minus 1°C. This is the only way that you will have a controllable experiment. Hotter temperatures will see the colour extracted much better than lower temperatures and grain that makes the water reddish-back at 70°C could see the water almost totally black if the water temperature starts at close to boiling. I'm assuming here of course that you are adding the roast barley into your mash and so mash start temperatures are what's important.
- I have had successful dry Irish stouts now with barley roasted at 230°C for between 90 and 120 minutes. You will need to stir at least every ten minutes, perhaps even every 5 minutes towards the end as the grain starts to smoke . . . and I mean SMOKE !! Just make sure you apologise to any other occupants of your house before hand and be careful if you have a smoke detector at home, you don't want the fire brigade appearing unannounced ! The grain also tends to burn around the edges very quickly towards the end which is why the commercial process has the grain constantly rotating in a heated drum. Your aim should be grain that has gone almost entirely black but uniformly so. If the grain is still a tad brown inside then that sounds perfect, if its all black, you may find yourself having over-roasted it. Relax, roast away !
- Another important issue is the amount of grain that you roast at once. Essentially, the time required for roasting changes depending on how much grain you put into the oven. I once roasted 1500g of pearl barley at 230°C for 100 minutes and got a black coloured beer (8% roast barley, 92% pale malt). I then repeated the roasting step with 2000g of pearl barley at 230°C for 100 minutes and got a beer that was mahogany coloured, not quite black ! More recently I have roasted 2000g at 230°C for 120 minutes and got a beer that is 99% black . . . not quite what I wanted either ! The next time I roast I will use 2000g of pearl barley at 230°C for 130 minutes . . . wish me luck, the smoke at 120 minutes was alreadawesomeme !!
- And finally, a disclaimer I suppose . . . Roasting your own barley is a great way to ensure that you have yet more control over the final beer but . . . please don't roast all night and set fire to the stuff. I'm sure its quite possible to have it ignite and the way the smoke pours off towards the end I'd suggest caution. I tend to keep a 2 litre bowl of cold water at hand and, if the grains did ignite I would FIRST of all switch off the electric switch that supplies my oven and then I'd dowse the grain with the water. Be careful obviously as dowsing electric appliances with water when they're electrically live is a great way to electrocute anyone in the vicinity. If you have a fire extinguisher for electrical appliance fires all the better. Scared ? Good, now you'll be careful !!