To Filter or Not?

To date, with the few wine kits I have made, I have never filtered the wine before bottling.  Most of the wine kit instructions recommend filtering because it supposedly enhances the clarity of the wine, and removes some of the residual yeast cells that are still floating around.  With my valpolicella kit, the store gave me a coupon for a half day filter rental, so I decided to go ahead and try filtering this wine before bottling.  The store gave me a "Buon Vino Mini Jet" electric filter for the afternoon:  http://www.buonvino.com/minijet.html

The wine filter consisted of a pump connected to an arrangement of plates that force the wine to pass through a sequence of three filter pads, and then through an outlet to a long piece of tubing that carries the wine to a carboy for storage until bottling. The edges of the filter pads are exposed, which allows some wine to escape.  This is probably good for the pump, because if the filter pads get clogged, wine can escape through the sides, which prevents the pressure from building up.  Any overflow wine is collected in a drip tray which drains to a holding container via a length of tubing.

My valpolicella wine had been sitting for some time after clarification, and there was an inch of precipitate at the bottom of the carboy.  So, before starting, I racked the wine into a clean carboy.  This way, I didn't have to worry about the fine solids clogging up the filter pads.  I noticed that the racked wine was already pretty clear.

After the somewhat fussy process of sterilizing the pump and tubing, rinsing with cold water, and flushing water through the filter pads, I began filtering.  I was pleased with the filtration rate, which was a lot faster than what I usually get when I siphon wine from one container to another.  When the carboy of unfiltered wine was empty, I filtered the two litres of overflow wine.

The filtered wine was 'agitated'.  That is, there was a fine foam on the surface, which is meant to be the result of carbon dioxide out-gassing from all the mechanical agitation that happens during filtration.  It took a few hours for the foam to disappear.  As per the instructions, prior to bottling, I let the filtered wine stand overnight in a carboy fitted with an airlock.

Bottling was uneventful, and a sample of the wine tasted much like it did when I first tested it.

30 bottles of filtered Valpolicella

So, was filtration worth the effort?   Filtration seems like a really good way to degas the wine if there is any excess carbon dioxide or sulfur dioxide present.  It is probably a good way to remove any of the finings that are left in the wine after racking, but this only applies to instances of sloppy racking.  If you are careful with racking, your wine should be very clear and may not even need to be filtered.

I personally found it to be a fussy process that creates a number of opportunities to contaminate the wine (e.g. sterilizing and rinsing the wine filter is not easy because of all the little grooves and small parts).  Plus, the whole process is clearly a very good way to aerate the wine: the wine is squeezed through filter pads with high surface area (in air); the overflow wine sits in an open drip tray before flowing into an overflow container; the filtered wine flows at a high rate from the outlet tubing, and this created a sort of waterfall effect in the final carboy, mixing up the wine with lots of little air bubbles.  Basically, there was a lot of aeration.

Would I do this again?  On balance, probably not.

Apple Wine Racking & Tasting

It was just under three weeks ago that I racked the apple wine into a carboy where it could ferment to dryness.  At that time, I added three cinnamon sticks to add some flavour.  The bubble rate died off after a week, but there has been a low level of activity since then, with tiny bubbles forming on the surface.  This could be outgassing or maybe even the result of malo-lactic fermentation (MLF).  There is a lot of malic acid in apples, so MLF would not be surprising.  Today, I decided it was high time to rack it and perform a taste test.

I siphoned the wine into a clean carboy and added two crushed Campden tablets.  During the siphoning, I dispensed a small amount into a glass.  After stirring the wine to remove sulfur dioxide, measuring the specific gravity, and installing an air lock, I sat down with my notebook, pen, and glass of apple wine.

This is the best wine I have made to date.  The bouquet was of obviously of apple, but there was a hint of pear.  The taste was simply delicious and mild.  I was surprised at how much body it had, given that the ingredients were so simple.  There was hint of butter, which suggests that there may have been some MLF.  The cinnamon flavour was very mild, and in the background.  I only really noticed it at the end.  It confers a subtle amount of spicy 'heat' to the wine.  The acidity was just right.  I tasted it at room temperature, and I suspect it would be even nicer when chilled.

Tasting and the taking of notes.

For me, as a scientist and chemist, it is a joy to sit down with a new wine I have never tasted, and taste it carefully and slowly, with the intent to observe as much as I can.   A certain oenophile colleague of mine once pointed out how satisfying it is to try to describe what you see, smell, and taste.  Wine tasting is a lot more fun when you really slow down and pay attention to the complex mix of aromas and flavours that you experience in your nose and mouth.  A wine tasting wheel is a great help for this.

(As the wine isn't quite finished yet, this may be premature, but thanks to +Bob Perkins and +Pete Bottiglier for some of the tips you shared that I followed with this apple wine.  To your health!)
  

The Limitations of EZ Cap Bottles

For about two weeks now, my cider has been sitting in those cool looking EZ Cap bottles.  Two days after bottling the first batch, I noticed tiny bubbles rising to the top, inside the bottles.  I thought this was a good sign, as it meant that the secondary fermentation was working, and the cider should be nice and carbonated when it was all over.  The problem is that the bubbles have not stopped.  That can only mean one thing:  the EZ Cap bottles leak.

Bubbles can only form if there is somewhere for the gas to go.  If the bottle is under sufficient pressure, the CO₂ stays dissolved in the liquid, and there are no bubbles.  However, as soon as the pressure drops, CO₂ becomes gas, and bubbles become visible.  This is exactly like opening a pop bottle.  When you unscrew the lid, the pressure inside the bottle drops, and CO₂ is released.

In exactly half of my 1 litre EZ Cap bottles, tiny bubbles are still forming in the cider.  Last night, I decided to open one of the leaky bottles and test it.  When I popped open the lid, there actually was an audible pop as if the bottle was under a small amount of pressure.  When I poured a glass, however, the cider was clearly not carbonated.  (So, I added some club soda and proceeded to enjoy!)

I really like EZ Cap bottles.  They look nice and they are easy to use.  I think they are perfect if your goal is to make still cider (i.e. non carbonated).  But if you want carbonated cider, you will need to use beer bottles and bottle caps, or maybe a plastic pop bottle with a tightly screwed lid.  Now, my experience might not be a total failure.  I still have hope for the other bottles of cider that don't have bubbles, because that suggests they are under pressure.  But here's the thing - a 50% success rate of getting a strong seal just isn't good enough for this purpose.

Here's my question:  Is there a trick to getting a good seal on EZ Cap bottles?

Bottling Cider

Yesterday, once I concluded that the fermentation was complete, I racked apple cider v.1 into a clean 1 gallon jug.  A secondary fermentation is required to carbonate the cider, so I stirred in some extra sugar - recipes often call for 1/4 cup of sugar per gallon.  I added a little less than this and stirred it until it was dissolved.  Then, I siphoned the cider into three 1 Litre EZ-Cap bottles.  The plan is to wait 2-3 months before I crack open a bottle.  This should be plenty of time for the secondary fermentation to be complete, and the lees to mostly settle out.

EZ-Cap Bottles.  Don't they look good?