In a small saucepan, combine the water, agar agar powder, red port wine, and granulated sugar. Whisk well to combine.
Heat the mixture over medium heat until it comes to a simmer, stirring occasionally.
Reduce the heat to low and continue to cook for 2-3 minutes until the agar agar and sugar are completely dissolved.
Remove the pan from the heat and let the mixture cool for a few minutes.
Cut a length of silicon tubing to your desired spaghetti length. Make sure the inside diameter is small enough to hold the gel mixture.
Fill a food syringe with the gel mixture and carefully inject it into the tubing.
Hold the tubing under cold water to allow the gel to set (inside the tubing). This probably takes a minute or so.
Once the gel has set, gently remove the syringe by taking it of the tubing. Add some water to the syringe, re-attach the syringe to the tube and 'push' the gel out of the tube using the water pressure.
Using a sharp knife, carefully slice the gel into spaghetti-like strands. Store until needed (up to two days)
Use it as a garnish for desserts, cheese platters or other dishes.