merlot color extraction.....

You get maximum color extraction by letting them ferment on the skins longer. 5 to 10 days or until the cap falls will get most of the color. This can safely be done in primary. Some sources suggest you ferment on the skin for 21 days or even longer. To do this you really need to use a CO2 source and keep a layer of CO2 over the fermenting wine. Cox discusses this in his book "From Vines to Wines". I have done it both ways and find that racking off the skins when the cap falls give me sufficient color.

Ray

Research I've seen suggests that color extraction actually peaks out for most reds around five days or so, so although you might think leaving it on the skins forever would help, it doesn't. The main thing is to let the fermentation get warm, at least 85 F (some say 90) to get good extraction. And give it those five days. Pectic enzyme won't make much difference one way or the other.

- Mark W.

Many people do as you are suggesting, Andy. Sulfite after crush and then wait a couple of days to add yeast, then ferment for a week on skins. Not sure how long you can delay adding yeast before something manages to start fermenting despite sulfite addition. I don't know of any reason to add pectic enzyme to your grapes.

Although high fermentation temps may well extract more color, the temps suggested (85F +) are outside recommended temp ranges for most wine yeast strains.

Miker

As was mentioned already, colour extraction peaks out in about a week and then the colour actually gets a bit lighter. Tannin extraction continues the longer the juice is left on skins.

To get good colour, some people do cold maceration - you can leave the must on skins without starting fermentation for quite a while as long as you can keep it cool - dry ice or ice jugs help.

In terms of enzymes, pectic enzyme will help breaking down the solids, so you'll get more liquid but also more pulp. There are other enzymes specifically designed to help with colour extraction and stabilization

- look at Lalvin or Scott Labs site for more info.

Pp

Since you said you were bringing grapes to room temp. and crushing Tuesday night, I assumed it would be too late for cold maceration. Also, I have always heard that vinifera grapes had no pectin so pectic enzyme was not needed, but looking at some other posts it seems unclear whether this enzyme may aid in other ways or not. Couldn't find a good reference to substantiate either way.

I've never used some of the other enzymes mentioned for color but I guess it shouldn't surprise me that these are available. There are also certain yeast strains recommended for better color stabilization (see the Lallemand website for example)

Miker

I was looking at Scott Labs catalog last night and see that they do not recommend adding pectic enzymes to red wine. This might actually lead to a loss in color. They say to use other enzymes, such as ones recommended by others here, for color.

Miker