It’s been about ten days since my last post, and since then I’ve pressed the wine into two 5 L demijohns. I made the decision to press when the ferments where almost dry. I had added the EC1118 a day before I planned to press, to ensure they fermented successfully to dry.
Wineries often use ‘clinitest‘ tablets to test for dryness, since refractometers don’t work well at lower sugar concentrations. These were originally designed for testing for diabetes, but helpfully are also perfect for wine. Lacking these, I used a dipstick test that may or may not also be effective for wine.
As predicted, pressing was an ‘interesting’ affair given the lack of an actual press, and one that took several hours. I initially began by attempting to press using the potato masher I’d been using to plunge the ferment, which did not really provide the level of pressure required. I ended up reverting to the age old technique of foot crushing — after cleaning my feet, I should add. In the event, it was a challenge to fill both demijohns; by the end I was pressing off maybe 20 or 30 mL at a time. Almost not worth it… The first demijohn received mostly free-run, plus some pressings, the second only pressings.
I was surprised — though I shouldn’t have been — that there were a lot of intact berries remaining in the ferment. I suppose I’m used to larger ferments, where the weight of the ferment would have crushed them. As a consequence, these berries released quite a bit of sugar back into the ferments, which restarted in the demijohns. Demijohns I had not bough air-locks for, so had to seal with clingfilm(!). Again, I should not have been surprised.
Intact berries can undergo intracellular fermentation, but this can only produce about 2.5% alcohol, at which point fermentation stops until the berry is crushed, and the yeasts can ferment the juice. This is not dissimilar to the carbonic maceration that is tyical of Beaujolais, but without the blanketing layer of CO2 — hence, it is often called semi-carbonic maceration. It is not uncommon in whole bunch ferments.
The free-run demijohn finished its primary ferment only a few days after, and I added another 25 g/L of sulfites. It is still bubbling slowly, however, so may have decided to undergo at least a partial malolactic fermentation. I have no way to test for this, however. This really is primitive winemaking!
The pressings demijohn is still bubbling away, two weeks after the ferments had first been inoculated. I’m used to inoculated wine ferments only taking 7 – 10 days, so I am somewhat surprised by how slowly it is progressing. I’m also beginning to wonder whether it is also undergoing a malolactic fermentation, which can occur concurrently with the primary, alcoholic, fermentation. Luckily, the grapes had plenty of fresh, lively acidity, so a malolactic fermentation would only help the wines.
It’s a bit hard to sample from the demijohns, so I don’t know how the wines are tasting. Hopefully, I will get to try them in April. As with any wine making, it is a matter of patience.