Fancy a brew?

Hello all,

I’m writing today to explain the basic principles of red winemaking. The easiest way to do this is to use the analogy of making a cup of tea (without milk).

When you make a brew, you can affect how it tastes, through….Temperature – how hot the water is. Agitation – how much and how vigorously you stir it. The variety of tea – different varieties vary in strength of flavour and tannin content (tannin being the stuff that makes your cup brown and has a drying effect in your mouth). Now, you can decide what your tea is going to be like by altering these factors dependent upon what you like to drink and whether you work in construction or not.

Red winemaking is essentially the same. Fermenting at higher temperatures  will mean that more flavours and tannins (which occur in grapes, not just tea) will be extracted.

The more I agitate the wine, the more I will extract. Lastly, different grape varieties have thicker skins and more tannin in them. So, as with most things, it’s about achieving a balance dependent upon the wine you want to make.

I have been fermenting my wine at around 22ºC which is pretty low for red wine. By doing this, the wine has retained a really nice fruity and floral smell.  

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Plunging, otherwise known as mixing with my stick. You can see the cap (grape skins) floating on the top.

When it comes to  stirring the grape skins, the wine has to be mixed daily to keep the grape skins (that have floated to the top due to being raised there by the carbon dioxide produced by the fermentation process) from festering on top. These floating grape skins are collectively called the cap.  I have mixed my wine using a technique known as plunging which basically involves pushing the cap down into the wine with a stainless steel stick. By mixing , I’m making sure that the cap stays wet and that the temperature throughout the tank stays the same. I’m also extracting the amount of tannin that I want. 

We all know that there’s no alcohol in tea (unless you like a dab of whiskey in your brew). In wine however, there is, which affects how much tannin is extracted from the grapes. The more alcohol, the more extraction of tannins (alcohol is a solvent). My wine will have a decent ;amount of alcohol in (due to the level of sugars in the grapes) which is another reason why I have been mixing only twice a day at lower temperatures. To bring you up to speed, the wine has finished fermenting and it is now going to stew for a while doing something that we call post-ferment maceration. That’s the subject of another post though…

Thanks and Adéu

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Bulletproof Vest

Hello all,

I wanted to give you a quick recap on where we are at and also talk about bulletproof vests…

The majority of the grapes were crushed and de-stemmed leaving 30% of the grapes just de-stemmed and not crushed. The juice was then kept cold and left for 6 days without fermenting in order to help extract colour. I then added my first yeast from a species known as Torulaspora delbreucki. After letting that ferment the wine for a few days, I added a yeast species from Saccharomyces cerevisiae. This second yeast is the most commonly used in winemaking and the particular strain I used was from Burgundy, France which is famous for its Pinot Noir.

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Yeast hot tub party. After getting used to the temperature, these yeast were then added to the main tank of grape must.

Now when you put the yeast into the juice it takes a couple of days for them to get used to their environment. However, once they have gotten over their initial shyness, they begin to party like it was 1999 and reproduce like crazy.  This is known as the exponential growth phase and is really where the fermentation gets going. This is a very important stage in the winemaking process. Why? Because of bulletproof vests.

I should probably expand on that now. Every yeast cell has a kind of outer coating called sterols which protect them from the eventually toxic (to the yeast) levels of alcohol in the wine. Hence “bulletproof vest”. The more sugar you have in your grapes, the higher the eventual alcohol will be and the more the yeast will need their sterols to survive until all the sugar has been used up.

Now then, yeast are single celled organisms (they consist of one cell) and when they  reproduce, they act like amoebas and split into two exact copies of themselves. So one yeast becomes two yeasts, two become four etc… BUT, the one thing they don’t replicate is their sterol content. So, imagine, one yeast has a bulletproof vest, it reproduces and now two yeasts only have half a vest each then a quarter of a vest and so on…

This is why the phase of exponential growth (when the yeast start to reproduce) is so important. We need to help the yeast produce more sterols and, in order to do that, they need Oxygen and Nitrogen. So, at this point, I have added some of the yeast food (consisting of dead yeast cells) I talked about in the last blog which is a source of sterols. In addition, when I added the food, I mixed the tank with a stainless steel stick and a lot of splashing around (to get some air into the juice). Normally Oxygen is not desired in winemaking as it can make the juice go brown and lose you some of the fruity aromas, but, on certain occasions, it can be very useful and a winemaker needs to know when it is a good idea to let some Oxygen in.

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“Beach-head inoculation” The yeast has been added to just one corner of the tank. This gives it a chance to adapt to the new environment before being mixed in.

So that’s where we are, the juice now has all the yeast added, it has been given some food and we have helped the yeast to be protected in their environment. The fermentation is currently close to half way through and everything smells and tastes as it should.

In the next blog I will talk about the basic principles of red winemaking and, in particular, how it is similar to making a cup of tea….

Adéu for now.

Fermentation basics

Hello all,

Now then, I just wanted to explain fermentation in a very simple way so that you can understand what it means and what happens in the wine during the process. We use yeast in winemaking because, basically, they like to eat sugar and convert it into alcohol. During this chemical reaction, heat is produced as well as Carbon Dioxide.

Yeasts are simple little beasts. They ‘eat’ sugar (which is their energy source) and Nitrogen (which they use to help make copies of themselves – i.e reproduce). The Nitrogen comes from the grapes themselves. The level of Nitrogen in the grapes depends on how fertile the soil is.

As the yeast eat the sugar in the grape juice, the environment that they are swimming around in becomes more and more alcoholic. The more alcohol there is in the wine (there will be more alcohol, the closer we get to the end of fermentation), the more difficult it is for the yeast to survive as alcohol is toxic to them. This means that winemakers have to monitor wine very carefully during fermentation, checking that there is no sugar left before the yeast eventually die.

Temperature

We can protect the yeast by making sure the fermentation temperature stays below 30ºC (the yeast will start to struggle at higher temperatures and will start to die if the temperature reaches above 40ºC). In addition, when you ferment the wine at lower temperatures, you will preserve more of the fruity aromas which are quite delicate and can disappear when the temperature gets too high. For this reason, I will be trying to maintain the temperature of the fermentation at around 25ºC.

 Food

We also need to make sure that the yeast has enough food. They have enough sugar in the grape juice (this mix of grapes and juice is often referred to as ‘must’ in winemaking) but what about Nitrogen? If the yeast don’t have enough food, or become too hot, they get stressed and start to give off an unpleasant smell reminiscent of rotten eggs. Nobody wants rotten eggs in their wine so sometimes we need to add yeast food in the form of Nitrogen to the fermentation.

Part of the reason why the grapes at this vineyard have such a concentration of flavours is because the soil is so poor and infertile. However, this lack of nutrients in the soil, means that it is quite likely that there will not be enough food (Nitrogen) for the yeast present in just the grapes. So, although I haven’t done yet, I will probably have to feed the yeast. This means, I will be tasting and smelling the wine every day and, at the first sign of any stress, I will add some yeast food. The yeast food is essentially dead yeast cells which will break down into the wine/juice and provide food (Nitrogen) for the living yeast.

Wild Yeast

There are many different species of yeast living on grape skins, so if you wanted to, you could squish some grapes, stick them in a bucket and one or more of the yeast species would start to ferment the juice. The problem is that not all yeast species are strong enough to ferment all the sugar in the juice. This can mean a fermentation stopping early and you are then left with a low alcohol, sweet wine. Also, some of the yeast species can produce vinegar and other unpleasant flavours in addition to the alcohol.

If you do just let any old yeast start fermenting the grapes, the effects can be great because you get a combination of different fermentation “styles” from the different yeasts which can result in a complex wine. BUT, the effects can also be terrible, leaving a half finished wine that only tastes okay on your chips.

A happy medium

I like the idea of “wild ferments” but I don’t want to make vinegar so I am using a combination of two yeast species which I have bought. I know exactly what yeast I am adding to the wine and what effect it will have. However, because I am first adding a different species than usual (this species can only survive in about 10% alcohol) and another more classic species to finish the wine off (this classic species can ferment wines up to 16% alcohol should you wish to), I will be getting more complexity (i.e a combination of aromas and flavours produced by different species of yeasts working in tandem rather than competing with each other) in the wine without any vinegary headaches.

Ok, that was a long blog, but I think it contained some pretty important information. Let me know if you want me to develop any of those points further….

Thanks and Adéu

Winemakers – at one with nature

Hello all,

The grapes have all been picked and are now sitting in a tank. Before I tell you what has happened to the grapes, I just want to make sure that you are all aware of what I have gone through to get these grapes.

The slopes in the vineyard are very steep with loose rock which has meant back- breaking work, not to mention long. But that was to be expected at this site.

What I didn’t expect was that, after only about half an hour of picking, I stepped on a wasps nest on the ground (actually two wasps nests working as a team). A busy few minutes ensued involving running, screaming (bravely) and frantic flailing.

Over thirty stings later (this is not an exaggeration), I now had a very fat left hand and a healthy fear of vineyards. So, after that, I picked a tonne of grapes with some help from some people who didn’t get stung once but do suffer from excessive smugness. The plus side to this is that I have found out that I am not allergic to wasp stings, so that’s nice….

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Filling the Crusher/de-stemmer by hand.

Ok, back to grapes. I have crushed and de-stemmed the grapes – separated the fruit from their stalks. Crushing is actually a bit of a misnomer as really you are only gently cracking open the grapes to release the juice.

I didn’t crush the first 30% of the grapes, I just left them as whole berries. When these ferment, they tend to retain more fruity aromas but the real reason I did it was because it takes longer for a whole berry to heat up (they have a higher thermal mass to be technical about it) and so it will help me control the temperature of the fermentation. More on fermentation in a later blog.

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Dry ice pellets on crushed grapes to protect from oxidation

The grapes are now in a tank with some dry ice (the stuff that you use for smoke machines) which will help keep everything cool and also protect the juice from oxidising. To put it simply, oxidation is the kind of thing that happens when your half eaten apple turns brown.

I don’t want the grape juice to do that as it will lose pleasant flavours and gain less pleasant ones.

Now the tank is sitting in a temperature controlled room to keep it cool. I will leave it like that for a couple of days, before I inoculate it with yeast – add yeast to start the fermentation.

I’ll do another blog soon, explaining fermentation and talking about the yeast I am using,


Adeu for now!

We have a date!

Hello all,

As I wrote in my last blog, I have now visited the vineyard, looked at the grapes and analysed them for sugar and acidity. I have made a decision about when to pick. The grapes are looking really healthy, no signs of disease at all, so that’s great news.

When I tasted the grapes I was mostly looking for flavour in the skins and checking to see if the seeds were ripe. When you normally bite into a grape seed it is quite astringent and bitter (as grapes grown for wine are much riper than those used as eating grapes).

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Garnatxa grape showing a ripe seed.

If you look at the picture, you can just about see that the seed is mostly a nutty brown colour. I expected it to be even browner in colour because the seed tastes rather nutty and not bitter at all. This is really important as the oils within the seeds will be extracted during alcoholic fermentation. I will be explaining more on this in a future blog post. But basically, because of the ripeness of the seeds, the wine I will be making will not have bitter flavours but will have more structure.

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The Winery at El Molar (a village in Priorat)

Anyway, the news is that I am happy with the grapes and I will be picking 1 tonne on Wednesday. I have commandeered a few things like tanks and barrels from another winery which I’ll be moving to my winery over the next two days. More importantly the next few days are set to be a bit cooler, especially at night, and this will allow the fruit aromas in the grape skins to develop even further which I am really excited about! Here is a picture of the outside of the winery to tantalise you all. It’s very small and artisinal which is how I like it. I’ll let you inside soon.

Adéu! (Catalan for good bye) 

What is ripe?

Hello all.

I have just arrived in Catalonia in Spain today. Now that I’m here, I suspect that most of the blogs (at least for a while) will be very specifically  about the wine I am making.

However, before I start in earnest, I would like to talk a little bit about the concept of grape ripeness (or maturity if you prefer). Ripeness is not solely about there being a certain amount of sugar in the grapes ready to be turned into alcohol. That will be a factor but ripeness, for me, really means “suitability”.

So, I will be picking my grapes when they are at their most suitable to be picked for the wine I am making. When to pick the grapes, depends upon the style and effect that the winemaker is trying to achieve. This will be different for every wine and a winemaker might pick grapes with different levels of sugar, acidity and flavour ripeness in order that the whole will become greater than the sum of its parts.

So, for example I will most likely be picking some grapes in the next few days. I will then pick some more grapes maybe a week or two later. The grapes are from the same vineyard and are the same variety and both batches will be “ripe”. However,the levels of sugar, acidity and skin flavour will differ. The idea is that these different fermentations will end up complementing each other. 

So, there’s a bit more to it than just grabbing all the grapes in one go and squeezing them into a barrel. I’ll keep you posted on when I decide to pick. In fact I should be taking some samples tomorrow……