Brewing
Brewing the easy way with ozone sterilization.

Intro

This project was inspired by (Dziugan et al. 2016):

Medium prepared from raw sugar beet juice and sterilized by ozonation is suitable for use in fermentation processes.

Instead of the traditional PBW washes and obsessive bleaching in homebrewing, I decided to test whether ozone can be used for effective and simple sterilant.

Procedure

  1. combine all ingredients except yeast in fermenter
    • no need to sterilize anything
  2. bubble ozone through media for 20-30 minutes
  3. let media rest while ozone dissipates (10-20 minutes)
  4. add yeast
  5. ferment as usual

Work Log

10 Jun 2019

This weekend I finally got around to using the strawberry wine with mixed results. It is hard to tell what people actually think of a wine when you ask them directly. They are always worried about offending you or hurting your feelings. One common response was that it tasted very alcoholic. When I tested the density, however, I only got about 8-9% ethanol. I suppose there could be dissolved solids that increased the density, throwing off the calculation. I also learned that not filtering the strawberry pulp before fermentation can increase the pungent aromatics that make a wine taste bad… next time.

Distilled some brandy from the strawberry wine. I don’t have a copper still, so I improvised with a short section of glassware stuffed with 1/4 inch copper raschig rings. Just a few inches of packing in total. It was probably equivalent to a one or two plate reflux condenser.

I discarded the “foreshot” and kept going until the temperature climbed to around 100C. The resulting ~240ml was slightly cloudy and smelled strongly of alcohol. I think the cloudiness is due to dissolved essential oils. It had a density of 0.9276 g/ml giving roughly 42% ethanol concentration.

I don’t have a corker handy, so I will probably distill the remainder just so it is stable.

31 Mar 2019

Filtered the wine through a “nut bag” to clarify. The carboy is only about 2/3rds full so I purged it with CO2 before sealing it again. The CO2 was generated by the reaction of magnesium sulfate and baking soda. The wine tastes pretty good after a quick decantation. I think I can call this a successful fermentation. Ozone works. I will bottle the wine so it can finish sometime in the next few weeks. Whenever I get a chance.

03 Mar 2019

Racked the wine. Tastes like wine…

28 Feb 2019

Strawberry wine is going well. It has almost finished fermenting. I had some trouble with foaming so I added 5-10ml mineral oil. It worked great. During the fermentation I swirled the carboy to mix the strawberry chunks. Currently the bubbling is once per second. Down from 2-3 per second at the peak of fermentation.

Unlike the fast-ferment sugar wash I did for lab grade ethanol a few months ago, the effluent gas from this wine doesn’t smell that bad. A slightly fruity and sweet number with a bit of alcohol. I’m perfectly fine leaving it on the dining room table to ferment in the open.

20 Feb 2019

Strawberry wine:

  • 6kg trimmed strawberries
  • 3.6kg sugar
  • EC-1118 yeast
  • tap water to make ~5gal

I didn’t sterilize anything or obsessively clean anything prior to use. I washed my hands. The carboy was previously stored with ~50ml of 95% ethanol inside to keep it clean. The strawberries were trimmed by removing the stems and any obvious damaged parts. They even sat at room temperature for 24hrs or so while prepped everything else. Some of the boxes may have been knocked on the floor by a cat.

I have no idea what the concentration of ozone is in the mini generator I pulled from a water cooler. It smells like ozone: that’s all I know.

I will know in a few days whether the ozone worked by the smell of the effluent.

Bibliography

Dziugan, Piotr, Maria Balcerek, Michal J. Binczarski, Dorota Kregiel, Marcin Kucner, Alina Kunicka-Styczynska, Katarzyna Pielech-Przybylska, Krzysztof Smigielski, and Izabela A. Witonska. 2016. “Ozonation as an Effective Way to Stabilize New Kinds of Fermentation Media Used in Biotechnological Production of Liquid Fuel Additives.” Biotechnology for Biofuels 9 (July). https://doi.org/10.1186/s13068-016-0574-2.