One of the benefits of home brewing your own mead is that you can experiment with new ingredients and ideas. Yeast is a prime candidate. The yeast used in champagne is commonly used for mead. Ok but why? Does it really make a difference? Tests were certainly in order to see if these choices are correct.

The recipe
To make sure only the yeast is tested I made one large batch for all the smaller tests.
15 pounds of honey
1 tsp gypsum
1 tsp Irish moss
1 gallon of water

Heated mixture at 155 degrees for 15 minutes. Don't get the water boiling as that will take away some of the smell and alter the honey. Though they do not hurt the final mead, the gypsum and Irish moss aren't really needed. Having made my must, I poured 1 gallon into 5 separate carboys.

In each gallon carboy I added 1/4 tsp of Yeast Energizer and 1/4 tsp of Yeast Nutrient. Simply put these act like caffeine and vitamins for the yeast. Each separate test had a specific gravity of 1.13 with a potential alcohol of 17%

Our candidates for testing
The following are the five different types of yeast that I used.

Lalvin EC-1118. A traditional champagne yeast. It's a tough strain that can finish very dry in the harshest of conditions.
Lalvin K1-V1116. A white wine yeast. White wine is closer to mead then red wine though neither is ideal.
Red Star Premier Cuvee. Similar to the K1-V1116 but made by a different company.
Red Star Pasteur Champagne. Would two champagne yeasts of different brands matter?
Red Star Montrachet. I chose 2 champagnes and 2 white wines so I wanted something different and went with a red wine yeast.

Starting off my experiment
I added the dry yeast straight into each experiment. Normally you want to follow the manufacturer's direction on re-hydrating and waking up the yeast so they aren't shocked when placed into the must. However for the sake of this experiment I put them straight in.

Lalvin EC-1118: Sank straight to the bottom and didn't dissolve but eventually floated back up. EC-1118 is traditionally known to be one of the toughest strains and they apparently are the heaviest.
Lalvin K1-V1116: This had the most noticeable yeast smell but nothing to indicate a problem|
Red Star Premier Cuvee: Floated on the top but didn't really dissolve.
Red Star Pasteur Champagne: Even though bubbles formed quickly the yeast would have to go through its lag phase before it went to active work on the honey so this was probably a by-product of it adapting to the water.
Red Star Montrachet: The Red Star red wine yeast foamed up quite a bit but no bubbles

An hour later
I was probably over eager but I checked back in only one hour to see how the yeast was adapting to their new environment. Fermentation still wouldn't start up for another day.
Lalvin EC-1118: Still in pellet form and it's not dissolving into the individual yeast cells.
Lalvin K1-V1116: The K1-V1116 is acting as expected and is dissolved and spreading out.
Red Star Premier Cuvee: No foam on top but there were noticeable bubbles formed.
Red Star Pasteur Champagne: Highest amount of bubbles and seemed to be the most active. Being champagne yeast I was not surprised.
Red Star Montrachet: Clear surface with neither bubbles nor foam.

One day later...
The meads are still very young and the different yeast strains have big tasks ahead of them to eat through the honey to make mead. After only one day there is nothing yet to measure so we'll have to stick to visual observations.
Lalvin EC-1118: The champagne yeast had a slow start but its active now with bubbles visible in the must.
Lalvin K1-V1116: Very little activity but there is a few bubbles rising in the must so I know that the yeast is at least active.
Red Star Premier Cuvee: The top of the surface is pretty clear but bubbles rising in the must to the top tells us it's just fine.
Red Star Pasteur Champagne: Clear surface on top. This is noticeably the strongest and fastest yeast with lots of bubbles rising and popping on the surface. It's definitely beating out the Lalvin champagne yeast.
Red Star Montrachet: The red wine yeast is coming along at a good pace for being in an environment it's not designed to be in.

One Week later...
The yeast should be well past the lag phase and reproduced enough of themselves to be making major progress through the yeast. I measure activity based upon the number of air bubbles released through each airlock per hour. It will give a good idea who is working the fastest and hardest.
Lalvin EC-1118: 5 bubbles/minute. The Lalvin champagne has a very large amount of yeast that has settled to the bottom. Lots of reproduction of yeast has occurred in here.
Lalvin K1-V1116: 5 bubbles/minute. The other carboys do not have any residue bubbles on the top they burst cleanly. Here though we have bubbles sitting on the top without bursting. That shouldn't cause any problems and is more of an observation.
Red Star Premier Cuvee: 5 bubbles/minute. Nothing unique it's going along and working.
Red Star Pasteur Champagne: 7 bubbles/minute. Very active and working the hardest. Lots of activity can be seen in the must with bubbles rising everywhere to the surface.
Red Star Montrachet: 4 bubbles/minute. The slowest in terms of consumption of honey but nothing to be concerned about.

End of Week 2
Having past the two week mark, we can now draw hydrometer samples to measure our progress. 1.000 is pure water and we started with 1.13.I'm not one to waste any mead so I also taste each sample that I've pulled out to see its effect.
Lalvin EC-1118: 1.022 SG. Even though the EC-1118 had the longest lag phase it's taken off and is racing through its honey
Lalvin K1-V1116: 1.054 SG. The white wine yeast is progressing nicely and right on schedule with what I expected. On interesting observation, the lees are not compact. The other strains of yeast have the old yeast cells settle down to o the bottom and compact together into a solid layer of yeast.
Red Star Premier Cuvee: 1.024 SG. A little bit ahead of schedule and all the strains are doing well. The yeast nutrient and energizer I believe really helped them all.
Red Star Pasteur Champagne: 1.016 SG. It is the furthest along and really no surprise based on the bubble activity from the previous week. It now has the most amount of yeast along the bottom of the carboy.
Red Star Montrachet 1.036 SG. I was surprised that it had made more progress than the K1-1116 white wine strain. At the end of week 1 it had the most less so this strain goes straight to reproducing and then switches over to eating the sugar. They seemed to no longer be interested in making more of themselves.

Another 2 weeks pass...
I now rack them to a fresh carboy as they have gone through their honey.
Lalvin EC-1118: 0.994 SG. As expected, the champagne yeast went through almost all of the sugar and we only have water and alcohol left. The yeast compacted very tightly on the bottom. I tasted my sample and it's not dry at all and more of a semisweet even though there wasn't much sugar left. Its holding up its reputation for being a good mead yeast.
Lalvin K1-V1116: 1.018 SG. Still a good deal of honey left and it seemed to have had a hard time to get through the honey compared to the other ones. Personally I prefer 1.000 – 1.009 so this is a bit too sweet but this is an experiment more than making it correctly. I transfer the yeast anyway. The flavor is too hard to tell as it's still too much honey for me.
Red Star Premier Cuvee: 0.994 SG. This too finished off all the sugar left. The taste was very unpleasant and alcohol but keep in mind, mead and wine are aged for months so I am not surprised.
Red Star Pasteur Champagne: 0.998 SG. Another yeast that finished all its honey. The smell is the most defining feature and it's completely neutral. That's something to keep in mind when picking yeast in the future on if you want a bouquet or not.
Red Star Montrachet: 1.01 SG. The Montrachet would normally need another week to get through the rest of the honey. The taste was quite nice and had the fullest mouth feel very similar to a red wine. Nothing different was done to this mead so it all had to come from the yeast.

The last evaluations and samples of drawn
take one last sample to measure and taste before they get bottled in another week or two after the experiment is completed.
Lalvin EC-1118: 0.994 SG. It's definitely done and the taste is still young and rough though it kept its semisweet flavor. A good 6 months of waiting will turn this into a good mead and this is a good mead yeast. It reached the lowest sugar level of all of them showing that it does deserve its reputation for being hard working yeast that will work no matter what.
Lalvin K1-V1116: 1.014 SG a little more progress. I'm not surprised it kept fermenting. Normally I would have let it continue and finish out the honey. Its rate slowed down because I siphoned off the majority of the yeast and the left over ones are fewer to continue the fermentation. This might make a good yeast strain if you have extra time to wait for it.
Red Star Premier Cuvee: 0.995 SG more honey? I attribute the rise in specific gravity to be a measurement error. At the third decimal point we are talking about 1 or 2 millimeter difference on the hydrometer. The flavor is very dry and very young. It seemed to have pulled out the flavor of the honey along with the sweetness. An ideal dry white wine but not the characteristics I want in mead.
Red Star Pasteur Champagne: 0.998 SG no change. Clearly the best tasting of the dry meads though nothing I would want to serve guests without several months of aging.
Red Star Montrachet: 1.008 SG. The yeast is still fermenting away as it should as there is still honey left. The fullness of flavor has decreased but is still noticeable.

Wrapping up the experiment
All 5 strains of yeast did what they are supposed to: eat the sugar in the honey into alcohol. However they each had very different ways of going about it and leaving behind different after effects in scent and taste. I believe it is obvious from this experiment that yeast choice does impact the final mead very much. A mead maker has a lot of choices in what they want their final mead to taste and smell like and proper yeast choice is indeed important as shown by this experiment.