Monthly Archives: May 2020

Mashing in

Lockdown brew day

Lockdown brew day

It’s been 3 months and… wait a minute do I sound like Sinead O’Connor here? Anyway it’s been a while since the last WE Homebrew meeting back in February and it could be some time still until the next meeting. I hope, like me, you’ve been brewing and drinking a fair bit more in this time.

It’s a bank holiday Monday and I thought I’d write down how I generally brew and what kit I have. No other reason than just to share and maybe elicit some advice on a glaring mistake I may be making and be completely unaware of.

I’ve got to warn you though – I’ve just finished the day and this is quite a long – and some might say – boring post. TL;DR? I had a big cock up at the end and spilt wort all over the shed.

First and foremost what am I going to make? This was a challenge set by Ben Jones to try a style I’ve not done before – a Weizenbock. I’ve had some success making a Bock before so in terms of recipe I just amended that and swapped out half the Pils malt for wheat malt then changed the yeast to try and get some big banana flavours. The recipe I’m following is as below.

Beer details – Challenge Accepted Weizenbock

OG 1055 FG 1013
ABV 5.6% IBU 12
Colour 20 EBC Brew size 20L

Mash ingredients

Ingredients Weight
Wheat Malt 2.5kg
Pilsen Malt 1.4kg
Munich malt 1.5kg
Special W (Weyermann) 0.1kg
Crystal malt 60L 0.18kg
Aromatic malt 0.28kg

Boil additions

Ingredients Weight Time
Hallertauer Hersbrucker 2.4%AA 51g 60min

Yeast

Type Lallemand Munich wheat beer yeast

If that’s what I’m going to make, how do I normally go about it? Firstly is preparation the day or so before. In this case I’m using a pack of dry yeast so no need to make a starter, from the fridge full of old collected yeast samples, but I do need to collect some water.

I use Old Windsor tap water – which as you’re probably well aware from the state of your kettle and shower head is remarkably hard. The water report for Windsor – here – shows the hardness around 300ppm and, more importantly for mashing, the Alkalinity at 240ppm. To ensure I get the pH around 5.4 once the grain has been mashed in I need to add some acid. I add about 12ml of 10% Phosphoric acid to 27L of tap water in an old plastic fermenter. I do this the day before in the hope that the water sitting and warming up in the house might lose some of the Chlorine added at the water works, but I’ve no idea if it does or not.

That’s the water quality – what about amount? This is where the first bit of kit is introduced. The electric mash tun / kettle. I do brew-in-a-bag (BIAB) so for water volume, in theory, you should just work backwards for how much wort you want to end up with, take off the losses of liquid you can’t get out of the mash tun, the trub you don’t want to transfer, the lost water as you boil off and the water absorbed by your grain husks. Then bung all that in at the beginning. However the mash tun is my capacity constraint. It holds 27L, but 3L of that is below the tap and is the cold break I generally leave behind. Then of course your grain takes up volume as well. 6kg of milled malted barley takes up 12L of volume dry. It obviously absorbs water so doesn’t need that much space in the mash tun, but I’ve more than once been close to overflowing when I mash in the grain to the water.

To remedy this I don’t add all the water into the mash. I dunk sparge the bag later with 5L of hot water – show you this later – and also add water back after the boil. So when working out the amount of grain I need I calculate the extract to hit my target OG before boiling. I then measure and dilute down the wort back to this gravity post-boil.

As you can see from the photo I’ve added some rudimentary insulation from an old camping foam Karrimat / exercise mat. As I brew outside in the shed this is necessary in the winter and helpful in the summer. It means I can heat the water to strike temperature then turn off the heating and avoid scorching the bottom of the mash tun and burning the bag or grain.

For this particular beer I’m using a low mash temperature 64℃ so I get the maximum conversion, with the thought that this won’t thin it out too much due to the gums in the Wheat malt. BeerSmith – the indispensable brewing app that I create all my recipes on – calculates your strike temperature and water requirement for each recipe. In this case it recommends 69℃ so I heat the water up and then mash in the grains.

One thing I didn’t mention is milling the grains. This I normally do using a drill attached to a hand mill while the water heats up to strike temperature.

Something to note with this recipe – Malted wheat mashes in really easily. There were no dough balls and the mash mixed in quickly and easily. As you can see BeerSmith got the strike temperature more or less right and the phosphoric acid did its trick with the pH.

I would imagine measuring pH at 65℃ is contentious. Measuring it at 20℃ or 25℃ would be normal lab procedure as pH changes depending on temperature. My meter isn’t so sophisticated that it compensates for temperature either. My thinking is that the optimum pH has been determined by looking at the kinetics of the amylase enzymes, this is generally accepted to be somewhere between 5.2 and 5.5. I don’t know the method used to determine this, and so have taken it to mean that the enzyme works best in this range regardless of temperature. I’m more than happy to be put right on this.

I generally mash for about an hour giving it a stir every now and again, when I get round to it, and checking the temperature’s not dropping too much. Today after half an hour it had dropped to 60℃ so I turned on the heat for a couple of minutes.

After the mash is complete I increase the temperature up to somewhere around 70-75℃.Then I use a Jerry-rigged pulley system, to a hook in the roof beam, to take the BIAB out of the mash tun and leave it to drip back into what is now a kettle heating up to 100℃ for the boil. At this stage I’m also checking on the efficiency as there’s still a small chance I can do something if it’s cocked up. I take a sample, to cool and measure the gravity, and determine the volume with a steel ruler to gauge the depth. In this case the gravity was 1066 and the volume was 20cm or 19L – ignoring thermal expansion of the liquid for now.  As you can see from the temperature photo the mash tun is very full. This is after me adding 22L of water and 5.6kg of grain. If I added no more water into the mix, after losses and boiling, I think I’d be fermenting about 13L of wort. To combat this I do a 5L dunk sparge, more to add volume than actually extract more sugars from the grist.

To do this I heat up 5 L of the acidified water to around 70℃ and dangerously swing the hot bag of mashings across into a big bucket. There I drop it in, add and mix the hot water and hoist it back over the kettle. One thing of note here is that boiling the acidified water causes it to become cloudy as the calcium comes out of solution.

This gives me another 5L of wort at 1038 that I can add back to the kettle so I finish with 24L of 1060 wort. This is great – I’m aiming for 1055 into the FV – so post boil it will allow me to add back quite a bit of volume.

By now the wort is boiling in the kettle and a little bit of hot break has always bubbled over and spilt on the floor. If I’m lucky it’s not scalded the dog.

For this brew I’m using fine German noble hops in the form of Hallertau Hersbrucker, but to be honest it’s really low BU, and there’s not supposed to be any hop flavour or aroma, so I’m beginning to wonder why I’m adding 50g of these when I could have added about 10g of Magnum? Too late now, the pack is open, and they’re tipped into the hop spider and plonked into the boiling wort to do their – in this case limited – magic.

Generally I’ll be boiling for an hour and, as it’s a hot day, it’s quite a vigorous boil. Brewing in winter has its own hurdles and I find it’s very difficult to maintain a rolling boil. This is why I first made the insulation which did help quite a bit but wasn’t perfect.

In terms of kettle additions this is very simple. No more hops to add, and as it’s a wheat beer it’s supposed to be cloudy, so I won’t be adding half a protofloc tablet to help it clear. I have, however, taken to adding a little yeast nutrient at the end of the boil. I don’t know if this is necessary but it hasn’t done any harm so far.

As the boil finishes, and I’ve added half a teaspoon of the Wyeast Beer nutrient blend, it’s time to cool. I pull out the hop spider and let the hops drip wort to the kettle (more as somewhere to put them as opposed to trying to eek out every last drop). I remove the insulation, sticky with boiled over wort from earlier. Often I have to peel it off the outside of the vessel. Then take a volume reading with the steel ruler – 22.5cm or 21.5L. The wort is hot so taking into account a 4% expansion of the liquid this means there is 20.7L of 1068 wort. I want 1055 so need to dilute with 5L of water to hit my target and leave me with a nice 26L of wort to ferment. Before that I’ve got to cool it and for that I use a length of coiled copper pipe. This is attached to the garden hose and immersed in the hot wort to run cold water through. Cooling takes no time in winter when the groundwater is at 11℃ but now it’s getting warmer the groundwater is 17.5℃ it may take a little while longer. I use temperature strips on the outside of the kettle to know when it’s lower than my fermentation temperature then I transfer it into the FV.

In terms of fermentation I had been reading up and found a lot of advice that in order to get a good banana flavour from the yeast you should aim on the high side of the recommended temperature. However I also found out that Lallemand makes two Munich yeast types: Munich and Munich Classic. The Classic version – not the one I have – is the more expressive one in terms of fruity esters and so I’ve made a bit of a balls up. Not to worry, hopefully this will still be a nice beer, just not what I had in mind. I’m still going to ferment at the top of the range to squeeze out what I can from the yeast so in this case that will be 22℃. This means I’ll cool the wort to below this before transferring across.

Transferring into the FV is very low tech for me. Just run the wort out of the kettle tap into a 5L sanitised measuring jug then tip into the vessel. I think this has two advantages; I don’t need to arrange everything so the kettle is higher, or involve a pump, to run through tubing and I don’t have to use tubing at all! I’m never convinced they’re clean. You can scour the inside of a jug – you can only flush through tubing or soak. It also allows me to add the dried yeast to the jug and splash the wort onto it. I’m not one for rehydrating the yeast beforehand – happy to chuck it into the mix and let it wake up when it does.

Well just as I thought it was all going so perfectly disaster struck. I poured the first jug of wort into the FV and it came straight out of the bottom. The Tilt (I’ll explain later) had jammed the valve open and so I was stuck like Hans Brinker with my thumb in the valve shouting for help. Got it sorted and cleaned up eventually and ended up with 21L pitched and fermenting at 22℃ and a couple of litres of sticky wort on the floor.

I have a love of gadgets and technology and this hobby allows me to indulge in both and get drunk too. As you see from the picture I have a Grainfather fermenter which both heats and cools. To cool I have a small Glycol tank stuck in my Keezer which the FV calls for and circulates through a jacket to control the fermenting beer’s temperature. I also make the FV wear an old down jacket (A Northface one I once had stolen off me by a tramp in Vienna) to insulate it from both heat and cold.

I mentioned previously the Tilt. This is an amazing piece of kit if you haven’t seen it before. It’s a wireless hydrometer that allows you to watch and plot your fermentation as it goes. For this beer you can watch this beer go by clicking on this link here.

So that’s it, that’s my set up and generally how I make my beer. I’d be interested on your thoughts and comments – any improvements or blindingly obvious steps or ideas I’m missing. Feel free to comment here on the website or head over to the Facebook group and let me know what you think there.

Cheers

Ian