• PartialMash
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Partial Mash #3

My third attempt at a partial mash. I will get sick of journaling these attempts sooner or later but right now I am on a learning curve and it is instructive for me (and hopefully others) to see how the process and/or equipment evolves.

Recap

1. For my first PartialMash/1 (American Pale Ale):

   1. I mashed in a SS pot which I kept in the oven to maintain temperature.
   2. I lautered and sparged in a large colander.
   3. Volume after sparging was 9L.
   4. Efficiency was 50-55% (but it doesn't matter)
   5. This method was my entree into mashing grain. It is quick, simple and can be performed with minimal investment. Definitely worth a try.

2. For PartialMash/2 (Czech Pilsner):

   1. I mashed in a 25 litre round plastic drum which I wrapped up to maintain temperature.
   2. I attempted a batch sparge but in the end I tossed all the grain into the colander. Had a few technical problems.
   3. Volume after sparge was 15L.
   4. Efficiency was in the 55-60% range.
   5. This was worth attempting, I learnt a few things about attaching a "manifold" inside a round plastic container.

3. For PartialMash/3 (APA recipe again):

   1. Mashed in Esky (rectangular cooler) to which I had fitted a plastic coupling.
   2. Successfully batch sparged.
   3. Target volume after sparge was 15 L and I hit 14 L.
   4. Efficiency was 70-75%.
   5. The mash/sparge process, although significantly longer (just under an hour) was much more efficient and low stress. The wort came out a lot cleaner than previous attempts. I just need to sort out my approach to draining the boiler and I would be confident I could tackle an all grain brew (with the addition of a bigger brewpot). I have got a feel for the efficiency I can achieve, the amount of water lost in the spent grain, the temperature drop between strike water and mash temp. By no means perfect but quite manageable.

Recipe

This was just a scale up of the Wild Arse Pale Ale in PartialMash/1.

Target Batch size: 23 litres ¹
Style: American Pale Ale

Equipment

The main changes to the equipment from my last go are:

The new Esky mash tun:

The strainer is a piece of stainless steel, tubular braid removed from the flexible "easy fit" tubing you can buy at Bunnings.

It is clamped onto the barb of a quick disconnect coupling with a flange fitting through the wall of the Esky. Closeups of quick disconnect coupling and where to buy can be found at Equipment

The Esky had a drain hole in the bottom so I left that alone and drilled a hole through the side to take the coupling. I first used a hole saw to drill the outer lining and the polystyrene foam insulation. I then drilled out the inner lining to the size of the threaded flange on the coupling. I used a knife to cut out a bit more of the outer lining to make it easier to disconnect the coupler. Later I decided to seal the insulation around the coupling because I didn't like the idea of wort soaking into the insulation.

I fitted a tap on the boiler:

Process

So the day went pretty well although lautering/sparging can really add to the duration of your brew day. The whole mash/sparge thing went a lot more smoothly than last time, the process requires some patience, the total lautering/sparging time took 55 minutes to get 14 litres. The wort came out quite clean compared with my previous attempt. I also added some Irish Moss to the pot at 15 minutes.

Another change I made was to add a tap to the boiler (19 litre pot). Last time I ended up with pretty much everything in the fermenter, given that the wort was not that clear to begin with this is not ideal (although not a killer).

Unfortunately the clogging power of hop pellets is unbelievable. Initially, nothing at all came out when the tap was turned on. It turns out it has a little filter inside the outlet, removing that got things going. Now the challenge was to keep the hop residue in the pot while getting the wort into the fermenter. This was problematic because I ended up putting my hands in the wort a few times (I did take the precaution of dipping my hands in weak phosphoric acid solution beforehand). I wedged a bit of stainless steel kitchen scrubby in the inlet of the tap. This filtered fine but soon choked on the solids in the pot. Anyway, I basically screwed around a fair bit and I left about 600 mL of wort + junk in the pot. I will definitely have to sort this out before next time.

Also because of the lower wort volume, I only topped up the fermenter to 20 litres so as not to dilute the wort too much and end up with a watery beer.