Yeast nutrient is a blend of nitrogen compounds, vitamins and minerals that feeds the yeast itself, as opposed to the sugar, which is what the yeast turns into alcohol. In a country wine you should not skip it, because a bucket of hedgerow fruit, sugar and water is a thin diet for yeast, and underfed yeast ferments slowly, stops early and leaves smells behind it that nobody wants in a glass. That is why a sachet of it sits in our Hedgerow Wine Making Kit next to the yeast. Here is what it is feeding, and when you can reasonably get away without it.
What does yeast actually need to live on?
Sugar is the fuel, but it is not the whole diet. To build new cells and keep working for weeks, yeast needs nitrogen above all, plus trace vitamins and minerals. Nitrogen goes into the proteins and enzymes that do the fermenting. Without enough of it, the population never gets large enough to finish the job, and the cells that are there work under stress.
Winemakers talk about this as assimilable nitrogen, which simply means nitrogen in a form the yeast can take up and use. Grape juice, particularly from sound, ripe fruit, usually carries a decent supply. A must made of blackberries, a bag of granulated sugar and four litres of tap water carries very little.
Why do country wines need it more than grape wines?
Because of the dilution. A commercial grape wine is fermented from juice, and that juice is the whole of the liquid. A country wine takes a few pounds of fruit, adds sugar for strength and then makes the volume up to a gallon with water. The flavour comes through beautifully, but the nutrients that came with the fruit are spread very thin.
Some fruits are worse than others. Elderflower wine is made from flowers, so there is almost nothing there beyond what you add. Rhubarb and apple musts are acidic and light on nitrogen. Root vegetable wines, the parsnip and beetroot classics of old country recipe books, are notoriously slow starters. Berry wines are usually the most forgiving, and even they do better with help.
What goes wrong without it?
Four things, in roughly the order you will meet them.
- A slow start. The airlock takes days rather than a day or two to show anything, and you begin to wonder whether the yeast was alive at all.
- A stuck fermentation. The wine ferments well for a week, then simply stops, leaving sugar behind and a wine that is sweeter and weaker than the recipe intended.
- Sulphur smells. Nitrogen-starved yeast produces hydrogen sulphide, which is the rotten egg or struck match smell that turns up in home wine far more often than anyone admits.
- A general lack of life. Even where the wine finishes, stressed yeast throws harsher, less clean flavours, and the difference is obvious once you have tasted both.
None of this is dramatic and none of it ruins your weekend. It just quietly makes the wine less good than it could have been, which is a shame after eight to twelve weeks of waiting.
When does it go in, and can you add more later?
At the start, with the yeast, in the quantity the recipe book gives. The first fermentation is the vigorous one, with the crushed fruit sitting in the liquid for about three days before you strain it off, and that is when the yeast population is growing fastest and needs the most support.
Adding nutrient partway through a sluggish fermentation is a recognised rescue, and it often helps. It is not as good as having it there from the start, because by then the yeast has already been stressed and may have produced the off aromas you were trying to avoid. Use it as a fix, not as a plan.
What you should not do is treat nutrient as a dial for strength. It will not make a stronger wine. The alcohol comes from the sugar, and the yeast will stop somewhere around 13 to 14 per cent whatever you feed it.
Can you ever skip it?
Honestly, sometimes. A wine made from a very large proportion of good, ripe fruit with little added water has a better chance of finishing cleanly on its own, and generations of country winemakers worked without commercial nutrient at all. They also worked with more stuck fermentations than they wrote down.
The old workarounds tell you what nutrient replaced. Recipes call for a handful of raisins or sultanas, or a spoonful of strong tea, or the juice and zest of a lemon, and all of those are adding something beyond sugar: nitrogen, tannin, acid, trace minerals. The kit's recipe table still lists optional extras such as raisins to add body, and they are worth using for flavour as much as anything.
The practical answer is that the sachet is already in the box, it costs you nothing extra to use, and the downside of skipping it is a wine that may stall. There is no prize for making it harder.
What else is in the kit, and what do you add?
Alongside the yeast nutrient the kit contains wine yeast, pectolase, finings (a very fine bentonite clay, with nothing animal derived in it), citric acid, a stabiliser tablet and a steriliser (sodium metabisulphite), plus the recipe table. You supply the fruit, the sugar and the water, a five litre food grade bucket with a lid for the first fermentation, a five litre demijohn or second bucket with an airlock for the second, a siphon and some bottles.
The allergen line is contains sulphur dioxide and sulphites. Every ingredient is listed on the pack, and if you have an allergy question, email hello@sandyleaffarm.com before ordering. Wine making kits are for adults aged 18 and over.
Yeast nutrient FAQs
What is yeast nutrient made of?
It is a blend supplying the nitrogen, vitamins and minerals that yeast needs to build cells and work steadily. It is food for the yeast rather than an ingredient you taste in the finished wine.
Can I use bread yeast and skip the nutrient?
Bread yeast is not bred for alcohol tolerance or clean wine flavours, so it tends to give up early and taste bready. Use the wine yeast and the nutrient supplied with the kit and follow the recipe book.
Will yeast nutrient make my wine stronger?
No. Strength comes from the sugar in the recipe. Nutrient helps the yeast get through that sugar reliably, which means the wine reaches the strength the recipe intended rather than stopping short.
My wine smells of rotten eggs, is that the nutrient?
It is usually the opposite, a sign the yeast has been short of nitrogen. Keeping the wine at a steady 22 to 27 degrees Celsius and adding nutrient as directed at the start is the best way to avoid it.
Do I add nutrient at both fermentation stages?
Follow the recipe book that comes with our hedgerow wine kit, which tells you when each sachet goes in. Extra doses added on a hunch will not improve the wine.
Want to put a hedgerow harvest into six bottles of your own? Take a look at our wine making kits.
