Sunday, September 2, 2012

What on earth are enzymes?

Certain aspects of winemaking - yeasts, oak-ageing, filtration and fining are pretty clear but what about the use of enzymes? Even the comprehensive Authentic Wine by Jamie Goode and Sam Harrop only contains one paragraph on the subject.

I can’t remember how but I got into a discussion about it on Twitter a couple of weeks back and asked if anyone would volunteer to write a post on them.

Two young winemakers Leah de Felice Renton and Nick Jones who are part of a wine collective called Birds & Bats Wine Productions which makes ‘a series of one-off wines from around the globe’* bravely volunteered. Not being a scientist I have to say I couldn’t make head or tail of their first version so they kindly offered to rewrite it for dumbos like me. Here's their guest post:

"Enzymes exist naturally in wine and are also added to wine.  This subject is of interest because it is something most people don’t know about and it goes into a product we all regularly and happily pour into our bodies.  We are joining the fish fight, we are drinking real ale, and we are reading this natural wine blog because we are more curious than ever about what we are eating and drinking.  We are writing this so you know what we are putting into your wine and into your bodies and why.

Enzymes are like your front door key. There is one key for a particular door, or in the case of enzymes, one chemical reaction it can trigger. That reaction can happen in other ways but using an enzyme speeds it up.

Enzymes can be found everywhere.  They are in your mouth, in the trees, in your washing powder, in your tears, and even in that piece of cheese.  They affect the way you taste that glass of wine and they help you through a hangover in the morning.  Without enzymes we would have almost nothing and more importantly wine would not exist. 

Wine is the consequence of thousands of different enzymes doing their thing to grape juice. These enzyme keys are found naturally in the grape, in yeast and in the bacteria we use in winemaking.  Therefore, in order for us as winemakers to turn grape juice into a specific wine style, we must try to predict and control thousands of these enzymes.  As with much of the natural world we don’t understand it all, but in the last half a century or so, we have been able to establish a good grasp of the subject.

In this post we will spare you the complex, confusing and sometimes yawn-inducing enzymatic pathways of yeast and bacteria.  Instead we will give you an insight into commercial enzyme formulations that winemakers add to the wine you drink.

Commercial enzyme preparations have been added to wine since the 1970’s and have been subject to technological advances since that time.  They are produced from a range of natural, non-G.M.O. fungi using methods that are controlled in Europe by the International Organisation of Vine & Wine. Enzyme formulations aid winemakers by releasing and maintaining red wine colour; releasing and increasing aroma precursors (that the yeast use to give a greater assortment of aromas); improving the clarity and improving mouth feel and roundness of wine. 

There are many practical advantages to be found in the addition of enzymes during the processing of grape juice into wine that makes life easier for the producer and reduces cost to the consumer.  We add enzyme formulations to juice and wine because it allows us to speed up the winemaking process, protect consumers’ health (by avoiding infection of unwanted micro-organisms), release more potential from the grape and ensure the wine does not spoil.  It is in our interest as winemakers to protect our customers and to deliver a quality wine.

Essentially we will be using enzyme additions this year in the production of our own wine.  We cannot afford to spoil thousands of good grapes and we want the best for the person that cracks open the bottle.  This way we can reduce the cost to the consumer and make less of the sinister chemical additions such as the dreaded sulphites.

There is always a down side and it generally occurs in wine when a producer doesn’t understand what they are doing.  If you season a pan with pepper before you add the steak you scorch the pepper.  The result is substandard steak.  If you add the enzyme formulation at the wrong time you are likely to end up with substandard wine.  As with the execution of any quality product, prior preparation and planning prevents piss-poor performance!"

Now I’m not sure how many of the readers of this blog will agree with this. ‘Natural’ winemakers, I imagine, don’t add** (see comments) enzymes which according to Goode and Harrop are also used to boost yields so do pitch in with your views.  I'm happy to give a platform to anyone who wants to state the case against!

* Incidentally Leah and Nick pledge on their website to include 'every last detail of what is contained in the bottle'. I wish more winemakers would do the same. This year they’re working in Maury - you can follow their progress on their blog and on Twitter @WinesofMD (Wines of Momentary Destination - which is what they call their winemaking projects).