Making wine – sterilising the must

I have been making wine for over 20 years on and off. My mother and her sister made some elderberry and rosehip wine in the 1970s and I was fascinated by the process. They would refer to the elderberry as ‘Winter Warmer’.

I have tended to make wine from kits and started with a ‘hock’ which was always successful, and then some red and rose. I always made a gallon at a time as this was the simplest and easiest thing to do as kits were/are sold by the gallon (or five gallons).

Simple enough, add sugar and yeast and away you go. Making sure that the temperature was about 25 degrees C. I bought a warming plate, enough for one gallon and that worked really well.

A couple of years ago I made 5 gallons of elderberry wine and it was wonderful.
The recipe called for the elderberries to be boiled in water before cooling adding water, sugar and yeast.

Two years later I decided to make another batch of elderberry, this time not boiling the elderberries, but simply squeezing out the juice adding water sugar and yeast.

Yuk, the result was a dry foul tasting wine….why? Maybe if I left it for another year…or maybe not.

This year I bought a 5 gallon kit of red wine. With the kit came 9 packets to add at various stages. What were all these packets?

I started to investigate a couple, potassium metabisulphate and potassium sorbate. I found that the potassium metabisulphate is used for sterilising…anything. Why put this in with the wine must? Wouldn’t it neutralise it somehow affecting the taste.

Well this had always been my thoughts when I had seen a recipe suggest adding potassium metabisulphate or a Campden tablet to the must before fermentation.

However, this addition has the effect of sterilising the must from wild yeasts, which is essential if you want a good taste. Boiling the must has the same effect. Now it may be that the taste is affected a little, but better it does than spoil it totally. Of course boiling might be the best option in this case, but not always possible and indeed with some fruits might affect the taste hugely.

It has taken me to have a disaster for me to realise that you can and MUST sterilise the must before adding the desired yeast.

I had a mental blockage when I read about adding a Campden tablet to the must, in my mind this would impair the taste and so I didn’t do it, I ignored it. The blockage was that equipment could be sterilised and not ingredients.

I thought that sterile ingredients could not be fermented or would not be fermented. In fact there is still a small doubt in my mind now because if I do add the Campden tablet to the ingredients/must then won’t it affect the desired yeast when I add it?

I need to read about this further, but the reality is I will add a Campden tablet to the must to avoid failure.

The link above talks about how important the Campden tablet is. It also introduces SO2 which sanitises and antioxidises which prevents the wine from going off while maturing.


I went away and read some more on the same website at this page:

‘Unless we use boiling water or direct heat for flavor extraction, or unless we use pasteurized juice or frozen concentrate, it is important that the must be protected against bacteria and mold from the earliest moment, and against oxidation. We do this by adding sulfites to the must in the form of crushed and thoroughly dissolved Campden tablets or powdered potassium metabisulfite. This does not sterilize the must, but brings it to an aseptic level of protection against microscopic organisms that can do terrible things to wine.’

Ah, so the addition of sulphites doesn’t sterilise but makes it aseptic…but aseptic takes place under a sterile condition. Anyway, not to worry about the semantics I feel, the link also states this:

‘cultured wine yeasts are largely sulfite tolerant.’

Although don’t add too much!

The sulphites also ensure that SO2 replaces Oxygen and so ensures that oxidation doesn’t take place and degrade the taste of the wine.

This allays my concern about the sulphite affecting the wine yeast that I add and informs me of addtional benefits of being antioxidant.

Happy days


What have I learnt about my own learning from this?

In some respects if I do something and it gives me a result that I expect then I am happy. This may be down to laziness, or simply that I feel I don’t need to dig deeper, even though I knew that I wasn’t doing what the recipes recommended.

Doing things is most important for me as making a mistake or getting a poor result triggers me to solving the problem of why it has gone wrong and if the answer is not simple and straightforward I will dig deeper to find out what might have been the cause of the problem.

Digging deeper usually means a little searching around on the internet as I did in this example. If lucky I’ll find someone who has written something in more depth or I’ll find a book that I want to read.

So reading is integral to my deeper learning, and then applying this new knowledge by making changes to the process to try and solve the problem.

However, I must be interested in the first place!

I like to read and then apply.
I like to observe and then have a go.
I like to solve problems.
I am learning to reflect on my learning to take it to a deeper level.
Writing things down really helps my reflection.
In order to learn something it must first have meaning….(Papert)
I do follow KOLBs learning cycle; Doing, Feeling, Watching, Thinking, Doing..

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