The artisan elaboration of wine. Temperature is the key (I)

Craft beer is booming all over the world and the proliferation of home brewing kits has turned this practice into a real passion for many people. Home winemaking is less widespread, although it is not as complicated as it may seem, if you follow a series of specific steps that are not too different from what is done in any winery in the world. We are going to try to explain it in a simple way and in stages so that, even if you don’t feel like it, you can get to know a winery a little better from the inside.

  1. Shelling and treading. First of all, we need the grapes and, in this proposal, we are going to do it with red grapes. We need about 1.3/1.4 kilos of grapes per liter of wine. We have to remove the remains of leaves or shoots and destem the grapes from the bunch (thus eliminating the carbonic maceration method), which we can do by hand for a small quantity. The second step is to crush the grapes, which we will do with our hands, with force but without crushing the seeds. Plastic drums work well for this primary fermentation vessel, but they must be totally clean and should also have a tap so that the wine can be emptied later during racking. For those who really want to get started, there are manual crushers/destemmers available at reasonable prices. There are also almost complete kits on the Internet for this process, even with corks and a manual corking machine without too high an investment.
  2. Maceration and fermentation Maceration, the contact between the must and the skins, is essential for the extraction of aromas, tannins and color. At this time we can add potassium metabisulfite, which is an antiseptic to eliminate unwanted bacteria. With a clean glass we take out the must and add the metabisulfite (60 milligrams per hectoliter), stir vigorously and then return the liquid to the drum. During fermentation, the sugar in our must is converted into alcohol and it is the yeasts, which are present in the grapes, that cause the ‘miracle’. We can also add yeast to liven things up, which can be found in any wine store. Here we have a dilemma that is one of the debates in winemaking worldwide: indigenous grape yeasts are consistent with making ‘terroir’ wines, while addition makes things easier but can also change the original profile of the wine. We will cover the container, although we will make some holes in the lid so that the carbon dioxide can escape during fermentation.
  3. Temperature is key during fermentation. The must needs certain conditions (it will not start with less than 17/18 degrees) and, being for young wine, we should not raise it too much. In any case, we must prevent it from reaching 28 degrees. During fermentation, heat is produced and if the temperature drops, we will end up with oxidized wines (brownish in color) and with the so-called “cooking” aromas. To combat a rise in temperature, we can hose down the vessel(as we do in wineries with tanks and cooling jackets) or even use frozen bottles of water and submerge them in our fermentation vat. During fermentation, carbon dioxide gas is also produced, which pushes the skins upwards and forms what we call the ‘cap‘. Fermentation will last for about a week and, from time to time, the must will have to be pumped over the cap or the tank will have to be punched down. The latter means breaking the cap (2/3 times per day) with a wooden (not metallic) stick to remove skins and must, which is basic for obtaining color and the future olfactory and gustatory characteristics of the wine.

And so much for this first explanation: in a second post we will talk about devatting, pressing, malolactic fermentation… and bottling. We are getting closer to see our wine bottled 😉

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