Anyway, my guest blog will appear at some point within the next five weeks, and I will let you know when. The purpose of this blog post is to cover some of the technical stuff which I refer to in that post, but didn't have the room to put it in. Call this a very long footnote.
When I have finished with the sterilising solution, I then cover surfaces of all equipment with boiling water. I do not know whether this is necessary (I suspect not) but it is something I do. Twice I have had a demijohn crack from this - in both cases a brown glass demijohn, so beware.
I have been told in a home brew shop that what I am doing is not actually sterilising equipment, but killing any yeast that may be hanging around the surfaces of stuff. This is good enough for me, as proper sterilising seems to involve leaving things to soak in bleach - and I worry about what effect this would have on taste.
'Racking' is the process where you transfer the wine from one demijohn to the next, leaving the sediment in the first demijohn. This is also the stage where I get my first taste of the wine. What you need to do is put the full demijohn at a height (on a counter) and the empty demijohn below it (on the floor). Attach your flexible plastic tubing to a piece of stiff plastic tubing with a bund at the bottom. Lower this into the full demijohn, bund first, but not so far down as to touch the sediment. Suck the other end of the tube, so that the wine starts flowing, and put this end into the empty demijohn. As the wine in the first demijohn goes down, gradually lower the bund, so that it moves closer to the sediment. As it gets close, tip the demijohn so that the most liquid possible is siphoned up, but try not to disturb the sediment. The instant the sediment looks like it is going to get sucked in, tip the demijohn back, and withdraw the tubing. In fact, it doesn't matter if you get a bit of sediment - this is pretty much inevitable.
Once you have finished this stage of racking, tip the tiny amount of liquid in the bund into a glass and taste what you have made so far. This will give you some idea of whether you need any more sugar. Generally (but not always) you will. If the wine is sweet enough already fill the gap in the second demijohn with tap water. If you think it needs more sugar, fill the gap with a syrup solution made from a ratio of 1 pint of water:six ounces of sugar. This is not a hard and fast rule, but generally works.
Different wines will have different levels of sediment. For example, I find that elderflower has very little sediment, whereas blackcurrant has loads. Don't worry if up to a third of your demijohn is filled with sediment - this happens from time to time. Do make sure, though, that after you have racked the wine, you fill the second demijohn to its neck with the water or sugar syrup solution you have made.
When you have six full bottles of wine, you need to stopper them up somehow. DO NOT USE SCREW CAPS. This is really really important. If the wine starts to ferment again (and some of them do) then you have created a bomb that could cause severe harm - flying glass everywhere. Instead, use bottles with corks. You can stop them up with plastic corks (which are reusable) or real corks. The weak point of the bottle is then the cork, and any explosion will mean the cork shoots out and the wine fizzes over the top. This is annoying, but not fatal! It is the reason I store all my bottles upright.
If you use plastic corks, you can just press them into the bottle with your thumb. If you are using proper corks, you need a corking machine. When using this, dangle a piece of string in the bottle as the cork goes in, leaving enough length to be able to pull it out. This way, the pressure caused by compressing the air above the liquid is diffused, meaning less chance of the whole thing blowing its top. You may notice bubbles around the string immediately after the cork has gone in. When the bubbles stop (a matter of seconds, if that) pull the string out vertically.
I recognise that this is not my most interesting post - and apologies - but I hope it is of some help. If there is anything else technical that you want to know, just leave a comment anywhere on my blog and I will respond.