Hello everyone.
I thought that I should give a bit of an update to this thread, for those of you that have read through it.
I have a good handle on sugar washes now, thanks to all the help from this forum and the mother site. I can get a consistant 7 to 8 litres of 95% from my 70 litre washes now.
Many of my fears in the beginning were for nothing, and I underestimated a few very important things. Heres what I needed to know to semi/fully understand whats going on...
- Yeast is an organisim that has needs just like us. It needs oxygen to breath, food to eat, and a nice warm place to call home. In nature wild yeast grows on tomatoes and grapes. NOT underwater. It is a very resourceful creature, it has the ability to steal the oxygen from sugar to breath. We are exploiting this unique ability by "drowning" these poor little buggers in our wash. However, they dont drown the second you put them in the wash. They can live quite happily and even mulitply by the millions when there is easy "free" oxygen floating around in your wash. As soon as the "free" oxygen in the wash is used up, the yeast starts to drown and stops all multiplying. (This takes from a couple hours to a couple days, but for most people this will be around half a day) It then switches to the much harder job of "breathing" the oxygen out of the sugar, which leaves us with an equal amount of both CO2 and Ethanol. The CO2 floats off into the atmosphere and the ethanol starts to concentrate in the wash. Heres the kicker, this ethanol "piss" is toxic to the yeast. No yeast on earth can live in a concentration past 20% ethanol by volume. During all of this process, the yeast MUST STILL BE FED nitrogen. Or else breathing oxygen isnt going to be their problem anymore, cause they will be dead from starvation. As long as you have a "cap" of foam on the surface of your wash, your yeast colony is still alive and trying to breath the sugar and eat the nitrogen. When the foam cap starts to break up and sink, you are either out of sugar to breath, out of nitrogen to eat, or have a lethal amount of ethanol in the wash. The real trick is trying to time all of these processes so that we get the most amount of good clean ethanol.
- There are many foods that yeast can eat, but the thing that is essential in all yeast foods is the nitrogen content. The simplest of these is DAP which is just a chemical nitrogen source. Really no different than fertilizing your lawn.
- Anything added other than oxygen, sugar, and a nitrogen source are an attempt to make the yeasts lives a little easier. (e.g. Vitamin B) They are not required to "get the job done". The easier we can make their lives, the less nasty flavours we'll get, and the quicker the yeast can finish "breathing" all the sugar up.
So heres the process I use for a 70 litre wash.
Boil for 1 hour, 15kg sugar with 8 litres of water ( yes it really dissolves in that little amount of water) and 3 teaspoons of packaged acid blend (tartaric/citric). A real slow boil without the lid is how I do it. Cost: $16 Cdn
Add this to your tub, then add (2) 300ml cans of tomato paste for a food source. Cost: $3 Cdn
Add 6 Tablespoons packaged yeast nutirents (Dap, yeast hulls, etc) for a food source. Cost: $1.50 Cdn
Add 1 teaspoon epsom salts
Add 1 teaspoon soluble Miracle grow 20-20-20 for a food source and trace minerals. Look for a fertilizer that lists "Di-ammonium Phosphate" as the nitrogen source. Its getting hard to find here in Canada. All I see now is "Phosphate free" on the label. Its not critical to get the DAP, its just the best for yeast. If its not DAP its Urea which is fine in small amounts like were using. Keep in mind that you are trying to grow and organism, just like the carrots in your garden.
Add water until you get 70 litres total wash.
Stir everything like a madman for about 3 or 4 minutes with a large wisk. Doing your best to incorporate air into the wash.
Add a large size fish tank heater and set it to 30 celcius. Leave the wash overnight to equalize at 30 deg celcius.
The next morning, warm to 38 Celcius (use a thermometer!) 2 litres of clean water in a 5 litre bowl. (You can pitch the yeast directly into your wash at this point, but the survivabliity rate of the yeast is much higher if they are rehydrated in clean water)
Gently wisk the water as you slowly add 1 bag of bakers instant yeast. (450ml) Cost: $8.50 Cdn
Let the yeast sit for a half hour. It will grow alot so keep an eye on it!
Wisk the wash for a couple minutes and then pour the yeast into the wash.
Add a floating thermometer and put a loosely covered lid on the whole thing. Check the temp once a day to make sure your heater hasnt packed it in.
Within minutes you will start to see bubbles and the whole thing will go crazy forming a "cap" on the surface. This is a good thing.
What happens now is your yeast will have everything it needs to multiply. The "free" oxygen you stirred in, the food sources, and heat. Its not too concerned about the sugar at this point, as long as its not too thick a syrup (1.08 with a hydrometer)
The yeast will spend the next few hours multiplying like rabbits on ecstacy, to a point where they use up all the "free" oxygen.
This is where the yeast stop multiplying, so whatever army of yeast you have in there at this point is all you get. Keep in mind that you must FEED AN ARMY.
The yeast start to break down the sugar to breath, creating CO2 and ethanol. All the while eating up all the nutients you added in the beginning.
So I keep these things in mind now..
If the yeast runs out of food to eat or sugar to breath, they will die.
If the yeast get too cold or hot, they will die.
If the yeast create too much ethanol, they will die.
I dont worry about things like a tight fitting lid, aerating, vitamins, daily stirring, types of yeast, or anything else really. All of these things will give you small improvements, that you can play around with once you get to know your system.
I just watch the "cap" of the wash, it will tell you if everything is working the way its supposed too. One time I had the cap start to sink after 5 days at a hydrometer reading of 1.02. So I added 2 tablespoons of yeast nutrients and gave it a stir. Within an hour I had a new cap, and the wash finished out to .99 in two more days. I might be wrong, but I'm going to assume that the biggest challenge is keeping the yeast well fed until the point that they create so much ethanol they poison themselves. Which by the way is also the point at which you want them to run out of sugar to breath.
Anyway, I'm getting tired of typing and I have a batch running through atm, so I'll leave it at that and if anyone has any questions please feel free to ask. Thanks again to everyone here for all their help
Bob
I have read this entire site. To the point now where I've read soo many different things that I'm not sure where I should be focusing my attention. I'm wondering what you old fellas would do first?
