Category Archives: Winemaking

Wine Pressing and facts about Wine.

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Wine press
Sam And Heather pressing wine

The earliest known traces of wine are from China (c. 7000 BC). Mead, also called honey wine, is created by fermenting honey with water. The French are the biggest wine drinkers in the world. They drink 53 litres per person per year. (this fact is disputed because it is said that the Vatican drinks 73 litres per capita) People who are scared of wine have “oenophobia”.

Alcoholic beverages, including wine, are forbidden under most interpretations of Islamic law. Within ten years of the death of Mohammed in A.D. 632, wine was largely banned from muslim countries. Top sommeliers think that smell is by far the most important sense when it comes to drinking wine.

The custom of raising a glass to one another and saying “cheers” before drinking originated with the Romans and the Greeks, who used to offer wine to their gods before celebrations. The world’s oldest bottle of wine is over 1600 years old and can be found at a museum in Germany. It was buried nearby in 350 CE and was found again in 1867.

There is scientific evidence that moderate, regular wine drinking can reduce the risk of heart disease, Alzheimer’s disease, stroke, and gum disease. Heir to the British throne, Prince Charles, drives an Aston Martin DB5 that’s powered almost entirely by wine derived bioethanol. It is a convertible and the wine powered car averages 300 miles per year.

It takes about 4 or 5 years for a newly planted grape vine to get to full production. A single celled organism called yeast converts the sugar in grapes into alcohol and carbon dioxide, and also release heat in the process. 70% of the alcohol is produced in the first 7 days of fermentation. This is called primary fermentation. At the start the wine can ferment so fast that it appears to be boiling. If the yeast converts all the sugar into alcohol it is a dry wine. Wine ferments fastest at 21C. Yeast will die at 37C.

Pomace
The pomace left over after pressing wine.

Pomace is the solid remains of grapes, olives, or other fruit after pressing for juice or oil. It contains the skins, pulp, seeds, and stems of the fruit. Wine fermenting at high temperatures creates more acetaldehyde which is a chemical which can produce hangovers so it is best if the wine does not ferment too fast. The largest wine producers in the world are France, Italy, and Spain. Michael Jackson used to order his wine served in diet coke cans during flights, due to being a ‘private drinker’ and not wanting his kids to see him drinking alcohol.

In a blind tasting it is very difficult for most people to differentiate between red wine and white wine (try this at home if you don’t believe it) . The Romans added lead to wine in order to give it a sweet taste and pleasant texture. Some people believe that the decline of the Roman empire was due to lead poisoning. For purists wine glasses should always be held by the stem and not the bowl because the heat of the hand will raise the temperature of the wine.

Enologists are wine chemists who analyse samples of wine and advise winemakers. In the late 19th century most of the vineyards in Europe were destroyed by the phylloxera epidemic because some infected vine cuttings were introduced from America. Phylloxera is a type of aphid which sucks the sap of the vine. American vines have adapted a defence mechanism against phylloxera. Nowadays, most vines in Europe have American roots and the top of the vines are grafted onto the rootstock.

Vineyards buy ready grafted dormant plants and plant them in the ground in winter. It takes at least 4 years before many grapes can be picked. The colour for red wine comes from the skins. Hardly any varieties of grapes have red flesh. Grapes contain all the necessary ingredients to make wine, the yeast is found on the skin and all the sugar and nutrients are found in the grape. A high concentration of alcohol will kill the yeast so the maximum strength of normal wine is generally around 15% alcohol by volume, but the exact amount will depend on the type of yeast.

Here are 3 videos of very small scale wine production in Spain showing the process of pressing the wine.

 

 

Crushing and Destemming Grapes to make Wine

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Grape Crushing Machine

Grape Crushing Machine

After picking the grapes we have to crush the grapes to allow the liquid to escape from the skins and also to separate the stems from the grapes. Many years ago the whole process was done by hand or by foot. The grapes were put into a big container and they were crushed underfoot. This would be a lot of work for even a small vineyard like ours. For this reason we use a detemming and crushing machine.  Our machine uses about 600 watts so as long as the sun is shining we can use the solar panels of the house to power it.

It is at this moment that we have to measure the sugar content of the must. This is the best way of knowing what the final alcohol percentage will be.  We use a refractometer to do the measurement. It works a bit like a prism which  reacts differently to light (by giving a reading on a scale) depending upon the amount of sugar that is available in the sample.

When the must (grape juice) comes out of the machine it drops into buckets. We then carry the must to the 200 litre plastic drums. After a couple of days the yeast from the skins of the grapes will start to ferment the sugars. This is called initial fermentation which lasts a few weeks depending on temperature and other factors. It is in the initial fermentation that the wine gets the color from the skins. In the wine made in the video below we allowed the wine to stay with the skins for about 4 weeks. This is probably a little too long and the wine picked up a bit too much tannin from the skins. This year we will press the wine (separate the skins from the liquid) sooner.

Making Pear Wine

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We have a large winter pear tree. Every year the pears fall onto the floor. By mid December they are almost ripe. Some of them have started to rot and the Jay birds have started to peck at them.  Winter pears are strange because if you pick them off the tree earlier in the year and store them inside they don’t go ripe. They seem to prefer being outside or they need some frost before they ripen.  About 3 years ago I decided to try and use my pear  windfall. After a while surfing on internet I found that the Roman soldiers who were stationed in Britain had no access to grapes so they bought pear trees with them and made pear wine. Roman soldiers tended to drink a litre of wine each day so they must have needed a good source of wine.

My pear wine recipe is very simple and could be very useful in a dystopian  post technological age in latitudes where there is no grapes but it is still possible to get sugar.
I suppose the Romans’ pear wine must have been pear beer because they had no access to processed sugar so the alcohol by volume must have been about 5%. (maybe they used honey)

Ingredients:
 A treeload of ripe winter pears maybe 100kg
Some yeast. I used Young’s Dried Active Yeast.
Lots of sugar.
Boiling water.
Sodium Metabisulphate

Equipment:
200 litre plastic barrel
Plastic trugs
Knives

Method:
Cutting up pears

Pick the pears discarding pears which are totally rotten.
Wash the pears in cold water to get rid of old leaves and other debris.
Cut the pears up into chunks. Maybe 1.5cm chunks. Discard all the really nasty rotten bits but keep the over ripe areas. I did not discard the cores. 

Throw the cut up pears into Sodium Metabisulphate solution and let them get covered in the solution.

Three years ago I did not use any chemicals and everything was fine but last year the whole batch of 150 litres turned to vinegar. I don’t like using chemicals but as I am using semi-rotten fruit hopefully it will stop it turning to vinegar. I got the pears out of the metabisulphate trug with my hands and put they into an intermediate trug before throwing them into the plastic barrel. 

Metabisulphate bath for the cut up pears

Metabisulphate bath for the cut up pears

The next thing to do it to pour boiling water into the plastic barrel as fast as possible. We use every available kettle and put big pans on the wood stove.  The idea is that the heat of the boing water will kill any unwanted bacteria. I don’t know how hot we managed to get the must but it was too hot to put a hand in, maybe 60C. 

Heating up water

Heating up water on the wood stove

The next thing to do is to put in a lot of sugar. I put in 22kg. It can be disolved in the water in the pans but it seems to disolve OK in the actual plastic barrel.

I used a refractometer and the sugar reading says that this has an alcohol potential of 5%.

I want the wine to be about 13.5% so I use my Chapitalisation Calculator

This is what it tells me

“You have 150 litres of must
At the moment your must has a potential alcohol volume of 5 %
You would like your finished wine to be 13.5 % alcohol.

To do that you have to add 24.23 kilos of sugar to the must.
BTW: That is 53.42 pounds

If fermentation goes OK I will add about 20KG of sugar after a couple of weeks.

It is very difficult to be scientific about the amount of alcohol because the pears are in chunks not in solution. Supposedly they have a sugar content which would be about 5% alcohol. The last bit of sugar is added bit by bit.

The yeast and Pectolase is added the following day one the liquid has cooled down.

Maybe I had beginner’s  luck with my pear wine 3 years ago. It was wonderful. The pears shrivelled and the wine cleared on its own.  All I had to was siphon it off in April.

I served it chilled to 11C and it was really tasty.

 

 

 

 

How to cork a wine bottle using a hand corker.

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This is my first ever instructional video explaining  How to cork a wine bottle.

bottle corker

The bottle corker

Why do we bottle  wine

Putting wine into a  bottle with a cork is an excellent way of keeping the wine until you want to drink it. When wine is stored it should only have a very small amount of oxygen available. Uncorking  a bottle of wine is a pleasant ritual which many prefer to using a screwtop bottle. The corks seen in the video are number 9 corks and are they are the most common. They should last 10 years with no problem.

When to bottle wine
The simple anwser is when no more gasses will be created which could cause the bottle to explode. Wine made from Grapes is picked in the Autumn. The initial very vigourous primary fermentation when most of the sugar is converted into alcohol, lasts about 10 days. The fertmentation then slows down and then many people say that the wine should be kept in a cool place for the  first winter.  The cold temperature seems to help the wine clear. The wine is just about drinkable by March of the following year and by May it should taste good. However, wine is not generally bottled until at least one year after it was first  picked because  sometimes  more subtle types of fermentation can occur such as maleoactic fermentation. This could create carbon dioxide which may cause the bottle to explode. Other types of wine such as champagne and fizzy wine can be bottled when fermentation is still active but they need high pressure bottles and a special cork. It is possible to stop a wine fermenting when it is still sweet by adding Potassium Sorbate which stop the yeast reproducing. However we never put chemicals of any kind into our wine.

 
Cork crusher

Where the cork is crushed.

The video below explains how we put cork into the bottles. For a very small producer like ourselves, a small floor mounted hand corker is enough for our needs. In reality we store a lot of our wine in recycled 5 litre plastic containers. However, a bottle of wine with a cork and a label is a pleasant object so we always bottle some to give away as gifts and to add a sense of occasion when sitting around the table etc. By the way the sphincter like crusher in the centre is called an iris. It dilates and reatracts a bit like the iris in an eye.