I wouldn't have thought that such a thing was possible, but here we are in mid March, I have lots of parsnips still in the ground and they're all growing like crazy. At least, that was the situation a few days ago. Growing parsnips are not going to store for long, even if I lift them all and try various tricks I've read about, such as removing all the little roots, cutting the tops off and dipping the cut ends in wood ash (gives you a couple of weeks' storage, apparently). I needed to do something with these.
Of course, I could make a big batch of parsnip soup and freeze it, but it's getting to the time of year when I don't fancy thick, warming soups, and I suspect there might be quite a lot of it still there by the time I'm harvesting next year's parsnips. Besides, I had an idea...
I enjoy my home-brewing, but it bothers me a little that the main ingredient - sugar - is not something I've produced myself. What I'm doing is essentially buying sugar (either refined white or malt extract) to ferment, then adding foraged flavourings. However, parsnips are quite sweet and I've heard that parsnip wine can be pretty good. I wondered whether I might be able to brew a drink purely from the sugars in parsnips.
Estimates for the sugar concentration in parsnips range from 5% to 10% and I could reasonably hope they'd be at the upper end of that at this time of year. On the other hand, I probably wouldn't be able to extract it all, so that would bring it down a bit. A rule of thumb for potential alcohol content is that 1 lb of sugar gives 1% of alcohol in a 5 (UK) gallon batch. For my 3 lb parsnips, an upper estimate would be almost a third of a pound of sugar, so in one gallon that would be 5/3... about 1 ½%. You're not going to get drunk on that, but maybe enough to be worth a go. I subsequently found more parsnips - several monsters that I'd allowed to run to see last summer - which doubled the quantity, so I could be looking at up to about 3%. That would be good, but is probably very optimistic, given the likely inefficiency of extraction.
I looked up various sources of information on how to process the parsnips. Wine recipes recommended cooking fairly briefly, so the veg doesn't start to disintegrate and distribute tiny particles of parsnip throughout the liquid. Descriptions of how sugar beet is processed include finely chopped beet being passed through hot water... hm,
hot doesn't sound like boiling, I wonder whether heating at a lower temperature might be the answer?
I sliced my parsnips fairly thinly, covered with water and brought to the boil, then reduced the heat to barely simmering, which I kept it at for about an hour. Sure enough, the parsnips were in no state to mash at the end of it, and the liquid tasted distinctly sweet. I strained the liquid off, hung the veg up in a jelly bag, then decided that was a waste of time and put it in the press instead. The strained liquid was about half a gallon, and I got another 2 ½ pints from the pressing, which I then brought back to the boil to sterilize (easier than sterilizing the press), which probably evaporated some off, so about ¾ gallon in total.
There were a few things I did for flavouring. First, I put a few of the parsnip slices in the oven and dry roasted them to caramelize some of the sugars, then added these to the pan. Secondly, I took another ingredient that makes a popular foragers' ale - nettles - and boiled up some of those separately. This allowed me to check whether the flavours work together (they do) before adding the nettle tea to the parsnip liquor. Nettles are only just appearing here, so I didn't get very many - about half a colander full. A few more would probably be better. Ginger is often added to nettle ale, and parsnip seeds, of which I have many, have a somewhat similar flavour, so I threw in a teaspoonful of those. I didn't think of that until near the end of processing, so they might have no impact on the flavour at all.
When the liquid cooled, I attempted to take a hydrometer reading, which was quite tricky as I don't have a proper flask and it kept sticking to the side of the bottle I was using. I think it read around 2% potential alcohol, which is about what I'd expect from the calculations.
The yeast is now doing its thing and the liquid is bubbling convincingly. My next decision is what to do about bottling. Usually, I'd wait for the primary fermentation to finish, then add a little sugar to each bottle to
condition the beer - i.e. provide fuel for secondary fermentation so the beer's fizzy. However, the point of this experiment is to make a drink without using bought sugar, so I'd rather not do that. In the meantime, I have found another monster parsnip root, which might be the answer...