Home brew dunkelweizen – brew day

With a stonking hangover from Saturday night’s Burns night celebration, I got up on Sunday to start work on the first run of home made beer with my newly-purchased brewing kit.

The plan: 23 litres of dark wheat beer – a dunkelweizen.

First up; the recipe:

• 3250g Wheat malt
• 2180g Munich malt
• 140g Pale chocolate malt
• 44g Hallertau Hersbrucker Hops (60 minutes)
• 11g Hallertau Hersbrucker Hops (15 minutes)
• 1 Wyeast 3068 Weihenstephan yeast

This recipe is approximately a metric-converted recipe I found here.

The brewing actually started on Thursday, when the gear turned up and I realised that the Wyeast packet which I received was a “propagator” pack and not an “activator” pack. The difference between the two is in the quantity of yeast in the packet; an activator pack containing enough to pitch straight into your beer and the propagator needing a starter culture. To make a starter culture just requires a small amount of malt extract and some boiling water, but having not realised I needed to do this I had failed to order any.

After a hasty conversation with a work colleague, I appropriated some extract and added my yeast packet to the boiled wort (water containing the sugars extracted from malt) in a sterilised milk bottle (also appropriated). I then stuck an airlock in the top and left it in a warm place until Sunday. This left me with a cloudy solution full of yeast, so on Sunday morning I stuck the bottle in the fridge to cause the yeast to form sediment at the bottom.

After sterlising and rinsing out the boiler, I filled it up, added some campden powder to reduce the chlorine and set it to heat. As discussed in my last post, I opted not to go for much in the way of water treatment. I was, however, worried about the hardness of my water. I opted, therefore, to boil the water forcing the calcium to precipitate in the water.

This was all well and good, and after letting the water settle for a few minutes once boiled I’d separated out some of the crap. Unfortunately this left me with water at ~90°C; not helpful for a mashing temperature of 50°C. Rather than wait for ages for the water to cool down, I decided to speed the process along with the help of the wort chiller. This also gave me a chance to test that I had managed to procure the correct hoses for it.

Everything hooked up smoothly and soon the chiller was running quite merrily. Too merrily, in fact; I balanced my thermometer on the edge of the bin, which caused it to fail to notice the temperature of the bulk of the water to fall to about 30°C. Not the best start. Back on with the boiler, then, whilst I calculated the temperature of the mash water.

I decided quite early on that I wanted to perform a “stepped” mash. This involves mashing at one temperature for a period of time and then raising it in a number of stages. The temperature of the mash affects the extraction process in a highly scientific way. I read somewhere that it was more authentic to have a 2-step mash for weissbier, and so that’s what I decided to do, with an initial half-hour at 50°C and then one hour at 66°C.

With the grain at room temperature, it’s important for the water you add to the mash tun to be hotter than your intended mashing temperature. Using a helpful calculator in the beer engine software, I calculated the heat of the water (strike heat) to be 55°C, and tested the water often so I knew when it hit this temperature.

Meanwhile, I warmed up the mash tun for 20 minutes with a couple of litres of boiling water. When the boiler hit 55°C, I drained the tun and added my dry grains. Then, using a big jug that I’d drawn some volume markers on with a sharpie, I measured out 14 litres of water from the boiler into the tun, stirred it and put the lid on; the grain at a perfect 50°C.

At this point I needed to figure out how to raise the temperature of the mash to 66°C. Using the very good (but sadly imperial) calculator here, I discovered that I needed about 9 litres of boiling water. And I needed it in the next 20 minutes. Unfortunately, I’d cleverly filled the boiler with  cold water after drawing off my mash water to prepare for sparging. This left me with a boiler-full of lukewarm water and a long wait.

By draining a lot of the water back out of the boiler and judicious use of the kitchen kettle, I was able to raise the temperature of the mash to the desired level, but I ended up with more of a 5-step than 2-step mash:

Time	Quantity of water (litres)	Temperature of water (°C)	Temperature of mash (°C)
0	14	55	50
35	2.5	100	59
40	2.5	100	62
47	2.5	100	65
50	1.5	100	66

 

Whilst I left the mash to infuse, the boiler was once again working away to heat up some water for sparging. When I ordered my gear, I opted to go for a spinning sparge arm and attempt fly sparging; in theory more efficient than batch sparging and more fun. Sadly, I couldn’t find a hose reducer anywhere locally and hadn’t quite twigged that the sparging arm didn’t come with one. This left me with batch sparging; draining out some wort, filling the tun back up and letting the grain settle once more.

With the optimum sparge water temperature about 78°C, I once again heated my water too much, but figured this wasn’t too much of an issue; I had some time before the mash was complete. I ran it off into my newly insulted fermenting bin to prepare the boiler for the run-off from the mash.

Placing the boiler under the mash tun, I turned the tap and collected the first few litres in a jug. This allowed me to see that the wort was very cloudy and thus the grain bed had not settled so I returned the wort to the tun and repeated until it was running clearer. Then I let the tun drain into the boiler.

I’d collected about 15 litres of wort and my boiler takes around 25 to the brim so I needed to run about another 10 litres through the tun (sparging). I decided to split this in half and checked the temperature of my sparge water. This was now sitting at about 65°C; so much for worrying about it being too hot. Cursing my failure with temperatures once more I stuck the lid on the bin to stop it losing any more heat and used a 5 litre stock pot to bring 7.5 litres more water up to temperature and added it to the mash tun.

After a quick stir and 10 minutes to infuse, I once again drew off wort from the mash tun into the boiler. Then sparged a final time with another 5 litres heated up in a stock pot. This last sparge resulted in a much lighter wort and I measured the last runnings with a hydrometer to have a specific gravity of nearing 1.010; a sign that I’d got all the sugars I was going to get and I was in danger of over-sparging which can result in an excess of tannins.

During the first sparge, I noticed my next disaster of the day; I’d forgotten to fit the hop strainer to the boiler. I now had a half-full bucket of 60°C liquid to try and fit it to. Fortunately, by the time I’d heated the water and allowed the sparge water to infuse, the boiler had cooled sufficiently for me to place my arm (well cooled with cold tap water) under long enough to stuff the strainer in. I then turned the boiler on to start getting the wort up to temperature.

With the second sparge complete, I had about 23 litres of hot wort which I measured at a specific gravity of 1.0457 (adjusted for temperature); way short of the 1.051 I was aiming for. This meant my beer was going to be closer to 4.5% ABV than the intended 5.1%.

When the boiler was up to speed and bubbling away, I tweaked the thermostat in an attempt to find the sweet spot where the wort would boil but not boil over; especially concerning as the bin was so full. I had one minor over-boil, but in general was ok; maybe a sign I under-boiled. After 30 minutes I added the first round of hops, and then the last 11g with 15 minutes to go; a total boil time of 1 hour 30 minutes. I then let it cool for about half an hour to let the hops and other gunk to settle out.

With the end in sight, I made sure my fermenting bin and wort chiller were sterilised then rigged up a sieve ready to catch any rogue hop debris that made it through the hop strainer.

Once the wort was run into the fermenting bin, I remeasured the specific gravity. I now had about 19/20 litres at 1.049 due to losses in the boil. As I was down on my target gravity anyway, I opted not to top this back up to 23 litres, which should give me a final ABV of around 4.8%.

I hooked the chiller back up and started it again, this time keeping an eye on the thermometer stuck to the side of the bin. In hindsight, I should have been keeping an eye on the hose, which not once but twice disconnected itself from the chiller and sprayed cold water all over the kitchen.

I did, of course, over-chill the water. Somewhat predictable given how the rest of the day went, but fortunately not too seriously. All that was left was to pour off the excess wort from the yeast starter, swirl up the remainder to pick up the yeast sediment and chuck it into the bin.

Lid on, job done… Except the washing up

Home brew dunkelweizen - brew day, 9.5 out of 10 based on 2 ratings