Wow, that's a lot of questions. I'm not sure that I agree with your instructor on some items, but here goes:
Excellent job Dean
and I will just add a few comments in blue to yours.
1.) Cold stabilization will help to remove bitartrates in the wine, otherwise known as wine diamonds. Tartaric acid precipitates out of the wine into crystal when exposed to low temperatures of 0 Celsius (32 F) for 2 - 3 weeks. This results in a softening of the acids in the wine. Most white wines and some red undergo this. This is only really needed on wines made from grapes, and not kits. The only kits that I know of that specifically talk about cold stabilization are RJS EP kits, and I think Mosti Mondiale might recommend it too. I have found many of my better reds kits throwing bitartrate crystals but only after a year in the wine cellar at ~56 degrees F. If you store your kit reds at a warmer temp you most likely will never see this.
2.) Your instructor mentioned Citric acid in your K-Meta solution. It increases the effectiveness of K-Meta as a sanitation agent by lowering the PH of the solution. The effectiveness of the K-meta increases since the molecularSO2 available is a direct function of the pH. This is why kits normally have a fairly low sulfite level sincethe amount added is calculatedbased on the pH of the wine when it is finished.
3.) Knowing what your TA is on your must, other than in kits is essential to good winemaking. The acid test kit measures the Titratable Acidity (TA) in the must, and I think the measurement is in grams per liter. Red wines typically go for about .65 and whites for .7. Again it all depends on style of the wine. Mostly this is used for really ripe grapes, which are low on acid, and this will help you to balance the must before fermentation. Kits are already acid balanced, so you don't need to do this in kits.
4.) Brix measures the sugars in the juice, and requires a refractometer, while specific gravity, also measures the sugars in a solution, but does so by density measurements. Brix tells us when the grapes are ready, and must be used on pure juice, as I believe that alcohol can throw off the reading. So use brix when testing a drop of grape juice, and SG when its in a must.
You add acid in granulated form of either tartaric, malic, or citric depending on what you are trying to accomplish. Once you have your TA, you can then calculate the additions (how much), in grams that you need to add to your must.
5.) PH is the strength of the acid in the must. Wine usually falls between PH 3.0 and 3.8. Anything above is highly susceptible to bacterial infection, and anything below that will taste like battery acid. PH helps so that you can taste the balance between acids in the wine.
6.) Yeast nutrient is essential to provide the yeast with additional ingredients that they need to perform a healthy fermentation. It is already included in kits, but is needed in almost any other must. It usually includes di-ammonium phosphate (DAP) which is a usable form of nitrogen that the yeast need. Depending on brand, nutrient will also include vitamin b, amino acids, and yeast hulls (cell walls from dead yeast). The yeast use all these ingredients to finish up fermentation. I just sprinkle my yeast on now, but if I must rehydrate it, I make a yeast starter.
6a) There are MANY different yeast strains that accomplish very different end results in wines. Some bring out flowery esters, while others kill off all wild yeasts. Here are the main yeasts out there:
Red Star Pasteur Red and Lalvin RC212 - used primarily for reds, and not mostly California since both these strains came from FRANCE!
Red Star Cote de Blancs, or Lalvin D-47 - primarily used for white wines and roses. Brings out the flowery character in whites when fermented cool.
Champagne yeast (RS Premier Cuvee, Champagne, and Lalvin EC-1118) are the most commonly used yeasts out there! I have no idea why your instructor would not use these. These yeasts are very fast ferementers, have low nutritional requirements, are low foamers, and high flocculation (means they stick together and fall out of solution fast when they are done). This is the typical yeast you will get in a wine kit, and a yeast that I use a lot for its predictable qualities. It is a neutral yeast, in that it doesn't bring out any esters or other aromatics in the wine.
Of course there are many other yeast strains that are common as well. Red Star Montrachet, and Lalvin 71B-1122 are generally used for fruit or country wines. D-47 from Lalvin is used for meads a lot. Lalvin K1V-1116 is used to start stuck fermentations and is a good all around yeast as well. I use it when other yeast will not work.
7.) Racking is the process of transferring the wine from one clean vessel to another, while leaving the collected sediment behind. This is typically the way to clear a wine when clearing agents are not used. Each successive racking will assist to remove more sediment. 1/4 tsp of K-meta will help to keep the SO2 levels up in the wine to help prevent oxidation when racking. I usually add that every 2nd racking, if doing it the long way around. Typically now, I add a fining agent like isinglass, rack off the sediment, add 1/4tsp of k-meta and then bulk age for a good long time.
8.) Wines contain malic acid, which is a harsh acid and very tart. This is the predominant acid in green apples. Sometimes when a wine needs softer acids, we introduce malo-lactic bacteria into the wine. This bacteria ferments the malic acid and turns it into a mild lactic acid. Hence the name malo-lactic. It also produces some flavor compounds like buttered popcorn, which many find pleasing in some white wines. Most commercial chardonnays and almost all reds undergo MLB to soften the acidic bite. Kits should NEVER undergo mlb because it would remove too much acid in them and leave them flabby. MLF can only be accoplished if the pH and more importantly SO2 level is in the proper range. NEVER try to do malolatic fermentation to a wine you added potassium sorbate to or it will wind up smelling like geraniums.
9.) Backsweetening is the safest method for a home wine maker. Ferment the wine dry, stabilize with K-meta and potassium sorbate, then re-introduce sugar in the form of simple syrup (water and sugar that have been boiled). The portion used is all done to personal taste and wine style trying to achieve.
10.) I NEVER soak my corks! Soaking a cork is a good way to get it stuck in the bottle as they adhere to glass when inserted wet for some reason. Dry insertion is the recommend way from all cork manufacturers. A floor corker really helps with dry insertion since it compresses the cork quite easily. Hand corkers do benefit from soaked corks, but a person would be better off using a smaller cork, #8 as opposed to #9, if using a hand corker. Almost all corks today also come with a bit of Teflon or other compound placed on the sides for easy insertion. Soaking corks is a very old way of thinking, and can cause issues. In the November FVW newsletter next month there will be an article on corks and cork preparation (Cork Humidor!) since as Dean says the old soaking method is everywhere you look and this issue comes up often.
I hope this helps...this was a long reply. Great Job!!!
Dean
