Sluggish ferment

[Uncle Jesse]

from the old message boards:


Anonymous
(Unregistered)
06/24/02 10:40 AM
subject: Sluggish ferment?

I started a wash for rum about 36 hours ago. this is the first time i've tried this, so im not sure what it should look like. Thus far, its only been bubbling slowly. Is something wrong that i could fix? Heres what I have done ths far. I made a 20L wash using 3k of sugar and 1k of mollasses. I couldn't find any actual nutrient in my area, so i used 2tsp of vegemite and a tblsp of tomato paste. I used bakers yeast for the wash. unfortunately, theres been a heat wave in my area, and im having a hard time keeping the wash cool, the best i can get it thus far is 28C, but i'll be lowering that in the next few hours. When i first thought it was going too slowly, i added some more yeast and wisked in some air. That made it bubble very fast for about 3 min, but it went back to normal after that. Any suggestions??


Dirk
(stranger)
06/25/02 08:35 AM
Re: Sluggish ferment? [re: Anonymous]

I have some experience with "baker's yeast" and sourdoughs because I like to bake bread.
Reading your post, made me wonder about some points: how did you obtain your yeast ? Was it "fresh" or dried ? Mainly when it is a dried product you have to treat it well before putting it to work. A large percentage of the yast cells have definitely not survived the drying process and the remainder need a initial "refreshing" treatment.

This means in practice: put first and for several hours the yeast into a WEAK solution of their future environment at the right temperature. I don't think 28°C is too high. The yeast cells can then recover, adapt at their new environment and come at full strength in this "hospital".

I learned from this website that after you pitch yeast into the wash it is important that initially it is important that it contains enough oxygen: the yeast cells will then multiply. Afterwards you shouldn't add anymore air because the production of ethanol is anaerobic.

Don't forget that "baker's" yeast is the yeast used for the commercial production of ethanol. This family of yeast cells has been chosen because they produce fewer undesirable by-products. Yes, they work more slowly and don't make it in higher ethanol concentrations... but it's not difficult to adapt your initial wash-density (sugar content) to these cells and profit of their low-profile demands and high-quality output.

Also, I would think that the addition of molasses should be plenty sufficient to have enough nutrients for the yeast cells.
I am afraid that adding other products could mean many times also the hidden addition of strong sterilizing products used in the food industry (= very harmful to the yeast cells)

Experiment and try to pinpoint the problem. Good luck !


Anonymous
(Unregistered)
07/02/02 09:35 PM
Re: Sluggish ferment? [re: Dirk]

Thanks for the help. I'll remember those things the next time I try making rum. The wash ended up fine, fermenting out in about a week. I ran it through my still (a pressure cooker pot still with a thumper, which has about 10 ft of 3/8 copper tubing for the condenser and the bridge between thumper and pot.) and got a distillate that was about 75% alcohol. Taste wise, the rum turned out really well, much better than I had expected.