So here's my little write-up of my first full "cycle" of birdwatcher's (In case it interests anyone).
In the end I started 4 15l batches all following the same proportions. The first stripping run yielded about 4l of low wines at 40% (Following the advice from NZChris) which was more than I was expecting. The following three washes ran the same with near enough the same yield. The stripping runs were run at 3kW, which seems to be approaching the limits of what my 78cm liebig can handle. The distillate was coming off at 40C. The 40% abv was a fairly rough estimate as I was reading it on my Ukranian mini-alcometer floating in the stainless steel pot that I was collecting in and correcting based on the guesstimate of 1% over read for each 3C over 20C. (Essentially looking for about 49%) When I checked the first batch of low wines before pouring them into the boiler I was actually at about 38% so I'm not too upset by my process.
For the spirit run, I had 4 batches of Birdwatcher's low wines, to which I added a litre of 54% low wines from my one and only turbo wash and a little water to bring them down to 40%. All in I had a little over 17l, which would allow me to take off 7 litres before the element risked being too close to the surface. I heated the low wines rapidly at 3kW, then pulled it down to about 600W (estimated) as soon as the first drops of fores appeared. I balanced the coolant to limit the water usage and started running. I was collecting in 300ml jars (jars marked for 300ml) and the first 2 jars were dismissed as fores (The suggested minimum would have been 360ml, but I figured I'd be in heads territory anyway). After that as I swapped each jar I logged the time taken to fill it, poured a sample into my (glass) measuring cylinder and recorded the temperature and apparent abv from which I then calculated the real abv and the flow rate. When I was reasonably certain that I was into the hearts (by taste) I pushed the power up to 750W, rebalanced the coolant (but not straight away so I got a slightly warm jar and lost a very small amount of vapour... I shall be whipping myself later by way of punishment!) and continued. From jar 13 I started tasting samples and in jar 14 I was reasonably sure I was getting some tails, jar 15 confirmed this, and so on jar 16, it having gotten pretty late at night, I ignored my 300ml mark, cranked the power back up to 3kW and filled the jar (about 700ml) before turning everything off. I don't have a reflux column yet, and I don't have the space to store lots of feints until I can build it, so I wasn't going to force myself to stay awake to try and collect the evil-tasting stuff for some future project.
Here is my table of "data".
Jar | ABV | temp | time | corr. abv | flow rate (lph) | notes |
1 | 82 | 18.1 | | 82.4 | | |
2 | 79.5 | 15.9 | | 80.5 | | |
3 | 79 | 15 | 0:09:22 | 80.2 | 1.92 | |
4 | 79 | 15.3 | 0:09:44 | 80.1 | 1.85 | |
5 | 79 | 15.8 | 0:09:14 | 80 | 1.95 | |
6 | 78.5 | 15.7 | 0:09:21 | 79.5 | 1.93 | |
7 | 79 | 16.7 | 0:10:00 | 79.8 | 1.80 | into hearts now i think |
8 | 78.2 | 15.8 | 0:10:05 | 79.2 | 1.79 | |
9 | 79 | 20.7 | 0:07:53 | 78.8 | 2.28 | Increased power to 750W |
10 | 86 | 48.6 | 0:08:05 | 78.6 | 2.23 | |
11 | 78 | 20.2 | 0:08:05 | 78 | 2.23 | |
12 | 76.5 | 17.3 | 0:08:45 | 77.1 | 2.06 | Missed the mark and overshot |
13 | 76 | 16.7 | 0:07:59 | 76.7 | 2.25 | |
14 | 75.5 | 17 | 0:08:08 | 76.2 | 2.21 | Definitely tailsy |
15 | 74.5 | 16.8 | 0:08:14 | 75.2 | 2.19 |
So what did learn from this run?
Firstly, while I can do a high-power stripping run of a 15l wash in an evening after the kids have gone to bed, the longer run time of a spirit run means I really need to be doing them in the day time. By 22h30 I'm not alert enough to be doing this. Forgetting to adjust the coolant was a stupid mistake, that I caught rapidly, but which could have gone wrong very easily. All in, the actual run took about 2h45 from when I started collecting. Add on the set-up time (I just powered down and went to bed at the end and took it all down this morning) and it takes too long to be comfortable in one evening.
Secondly, my current technique for collecting low wines works really well, but will hit the limits if I increase the wash size. Given that the next plan is HBB in 25l washes, I'm going to need a bigger collecting container as my biggest stainless steel pan can take about 4l before it gets unwieldy.
While logging the data is interesting, 300ml increments at 750W goes just fast enough that by the time I've done and recorded all my measurements it's time to swap jars. In the future I'll probably just log the time and measure the abv when I do the blend.
It would be really interesting to do a higher-powered spirit run of birdwatcher's and compare the jars directly (To continue the experiments begun in
Speed of stripping & speed of spirit runs) but I don't think I've got the time, or the jars necessary to do this. Maybe in a 6 months or so when I get around to extending the shed and moving the fermenting and distilling apparatus out of the house.
I'm going to rest the jars for at least a full 24 hours before attempting a blend. I'm not looking for a perfect neutral, just something vaguely flavourless to pre-age oak sticks, and provide a base for gin and berry macerations. I have an easy source of wheat and some high temperature enzymes so the next batch of neutral will probably be grain-based.
And that's enough verbosity...