The Boil

Back in October I wrote a post about our mash tun, and how we “mash” grain to make fermentable wort. So I thought I’d continue by describing the boil process.

Boiling sterilises the wort, extracts bitterness from the hops and develops rich toasted flavours. Generally we boil for an hour using a Baby Burco that I bought on eBay, although some beers require a longer, 90 minute, boil.

So let’s start. After we’ve run our wort out of the mash tun (see the previous post), we transfer it to the Burco:

The Burco is then turned on. As you can see (below), the wort produces quite a lot of foam to start with. We’ve had the odd boil-over because of this which is horribly sticky, so we generally watch it like a hawk at this stage.

Hops are added at various stages during the boil. These impart three things to beer: bitterness, flavour and aroma. To extract the bittering oils from hops they need to be boiled for a full hour. The problem with this is that the more volatile flavour and aroma chemicals are driven off during this time, so additional hops are generally added towards the end of the boil – often at 10 minutes before the end (for flavours) and a couple of minutes before the end (for aroma).

Hops can be bought in a number of forms: loose, compressed vacuum sealed and compressed pellets. Our hops come vacuum sealed and compressed, and look like this out of the pack:

After carefully weighing them they are added to the boiling wort:

The wort is boiled vigorously, which as you can see below requires careful monitoring. We generally drive off 15-20% of the water as steam – notice the way the wort has dropped down from the original scum line. Notice also how vigorously the wort is churning – it needs a good rolling boil:

At the end of the boil the wort must be cooled to room temperature to allow the yeast to be pitched in and the fermentation commence. Cooling takes a hell of a long time, so it was not long before we invested in a wort chiller, which allows cold tap water to be circulated through the wort:

Crash-cooling the wort in this way has another advantage in addition to saving time: it creates the “cold break”, which is the precipitation of some of the proteins in the wort. This happens at about 50C, and you can see little strands appear in the wort that look rather like Chinese egg soup. Getting some of the proteins out of the beer helps prevent hazy beer.

During cooling we monitor the temperature:

We also check the specific gravity (density). The denser the wort, the more sugars it contains, and the stronger the final beer will be. The density of the wort will be affected by the temperature (it gets less dense the hotter it is), and since our hydrometer is calibrated to be accurate at 20C we use some conversion tables I made to allow us to correct for the temperature.

Back in the old days beer pump clips and bottles used to state the “Original Gravity” (OG) of the beer. If you remember back to those days you may have seen Marston’s Pedigree as 1.043, Theakston’s Old Peculier as 1.058 and Marston’s Owd Rodger as 1.080. This gives a guide to the strength of the beer, but it does depend on how much residual sweetness there is in the beer. Two beers with the same OG may contain considerably different amounts of alcohol if one is very dry and the other very sweet. This is why these days beer strength is required to be quoted in Alcohol By Volume (ABV), which takes into account both the starting sweetness and final sweetness.

The boil is complete and the wort just needs to be transferred to the fermenting vessel and the yeast pitched in. This stage is the only stage in beer making where the beer is treated roughly. Under all other circumstances you really need to avoid dissolving oxygen in the beer, because of the resulting oxidation and the off-flavours it produces. But to get the fermentation started you need the yeast to multiply. This reproduction needs oxygen and the boiled wort will have very little in it. So at this stage and only this stage, the beer is splashed about a lot to ensure plenty of oxygen dissolves. The way we do it is to pour the wort from the Burco into the fermenting vessel from a height:

So that’s it. In goes the yeast and the beer (for once the yeast goes in we stop calling it “wort” and call it “beer”) is moved to a relatively warm place (18-20C) to ferment. Om nom nom.

Side by side tasting: Axe Edge and Owd Rodger

On Wednesday we decided it would be a good time to have a first try of Axe Edge – our strong dark old ale inspired by Marston's Owd Rodger.

As luck would have it our friend Andy (another beer maker, but not Cheshire Peaks Andy) had had a similar idea – and he turned up with a bottle of Owd Rodger so we could do a side by side tasting.

If you really want to make your side by side tasting as fair as possible, you pour three beers: two of one beer and a third of the other beer. Then your tasters sample the beers blind and see if they can pick out which beer is different. If they can’t then you can safely say that the beer is “cloned”.

However, we weren’t really after attempting to clone Owd Rodger; Axe Edge is merely inspired by the classic Marston’s brew. And anyway, we decided to sample Axe Edge hand-pulled from the cask (although we had also bottled some), so comparing cask Axe Edge to bottled Owd Rodger was never going to be very fair.

So, enough wiffling, what were they like?

Colour: Both deep dark brown, but Axe Edge was noticeably darker.

Head: Rather unfair comparison: Axe Edge had a rich, thick, cream coloured head which lasted for ages. The Owd Rodger, being bottled, had very little head.

Aroma: Surprisingly similar – both sweet and malty, but the Axe Edge had a more intense aroma.

Flavour: Again surprisingly similar. Sweet, rich, malty, chocolaty and alcoholic. Frankly, both delicious!

Bitterness: Owd Rodger was more bitter. We agreed that on this one Owd Rodger probably had it right. Next time we make Axe Edge we will increase the bitterness by 10 IBU (International Bitterness Units – probably need to explain that one in another post!)

We’re stout, and we’re proud!

On Tuesday we brewed “Mow Cop Stout” – a stout to our own recipe formulation. If you’ve been reading this blog regularly (is anyone actually DOING that??), you’ll have noticed that we have been brewing a great deal of dark beers recently. This is probably the last in that line: we’re starting to think about slightly lighter beers for drinking in the new year. But for now, dark, dark, dark.

And boy will this one be dark! I’ve never seen such thick black wort running out of the mash tun. One of the most common ingredients in stouts is roasted barley. This has a very dark brown colour and imparts a burnt, coffee-like flavour and a dry graininess. A bit like a rather well known stout. We’ve added plenty of chocolate malt too, which will hopefully make it a slightly sweeter, richer beer than its well-known cousin.

One last boring beer-making observation on our brew day: we completely forgot to add any minerals to our water! Usually we would add gypsum (calcium sulphate), calcium chloride, magnesium sulphate and common salt (sodium chloride) in varying quantities in order to emulate the mineral content of the area from which our target beer style comes from. This helps to adjust the mash acidity (so it mashes correctly) and also assists in enhancing flavour. Generally speaking, chlorides will enhance maltiness (think adding salt to food as a flavour enhancer) and sulphates will enhance the bitterness. So in theory you should be able to adjust minerals to compliment your style… only this time we were in such a rush to “mash in” we completely forgot the minerals! So, we’re treating it as an experiment… can we notice any difference? Time will tell. Many brewers don’t bother with water treatment anyway, so whatever happens we hope we’ll get something drinkable!

One last thing – in case you don’t know, Mow Cop is a lump of rock that sticks up out of Cheshire south of Congleton. On the top is Mow Cop Castle, a folly built in 1754 by the owner of a local hall (Rode Hall) as a summerhouse and to give an interesting thing to look at on the horizon from his house.

PS This time I managed to use my obscure Not The Nine O'clock News quote for the blog post title! See this post for why that matters!