PeteB Posted October 19, 2012 Share Posted October 19, 2012 I sometimes have a problem with rye foam in my pot still (alembic) Antifoams can help a little, but I would be nice to have a device that cuts the electricity to my still if foam rises more than a couple of inches. I would rather not add antifoam. I see there are forum members who build still controls, does anyone have any suggestions of a design I could build or would someone like to build one for me if it is possible! Link to comment Share on other sites More sharing options...
Absinthe Pete Posted October 19, 2012 Share Posted October 19, 2012 LOL who doesn't!!! Rye is very foamy. There are some tricks that can help. There is no problem using anti foam. I use about 3-4 liquid ounces per 160 gallons of 8% wash. I then set my agitator to a pretty fast speed. If that doesn't work I would suggest a control for your electricity that can regulate how much electricity is used and not cut the power, because then you'll get surging and your batch won't be consistent. That doesn't matter too much as hopefully you're doing stripping runs. I don't know what you're using for heating and what kind of power levels but one of the cheapest ways is to buy a variac. If you're not sure how they work PM me and we can talk. Here is a link to ebay that shows what a variac is. http://www.ebay.com/itm/20-AMP-110V-VARIAC-AUTOTRANSFORMER-VOLTAGE-REGULATOR-POWERSTAT-0-130V-OUTPUT-NEW-/380453842256?pt=LH_DefaultDomain_0&hash=item5894d0ed50 Link to comment Share on other sites More sharing options...
PeteB Posted October 19, 2012 Author Share Posted October 19, 2012 My heat source is direct flame from a converted diesel gun burner running on waste veg. oil. It is either on or off. I only have the problem on my stripping run, then usually for a short time just as it gets to the boil. I switch off the burner for a few minutes then back on, but if I get distracted even for 1 minute it can foam over. I imagine electrical probes could detect the rising foam. A multimeter in megohm scale certainly detects it. My electric supply is 240V and I also have 12v DC available. Link to comment Share on other sites More sharing options...
John McKee Posted October 19, 2012 Share Posted October 19, 2012 Foaming in distillation systems is often (75% or greater) the result of pH. Once Mash / Ferment is complete, add the appropriate food grade chemicals to get yourself to just shy of neutral and you won't have any foam or the need to add anti-foam agents. Anti-foam agents are surfactants which lower the surface tension, which in turn keeps bubbles from forming during boiling or agitation. As an aside, you can do this experiment next time you're tired of waiting for the head on your beer to go down. Stick your finger in your nose then swish that around in the head of the beer. Snot is a good surfactant and it'll knock down the head right away. The reason pH adjustment works so well is that the principles of surface tension can also be affected by the range of acid to base in which your final solution finds itself. Since food grade chemicals are usually cheaper than antifoam, it might make sense to go that route. Don't use snot. Link to comment Share on other sites More sharing options...
PeteB Posted October 25, 2012 Author Share Posted October 25, 2012 Looks like no-one has any ideas for a foam dector, so I will take advice from both the above posts. I have a backup burner under my still that I don't use, I will put a smaller nozzle in it and switch to that as I approach foam temperature. Would be nice though for switch over to be automatic. Maybe just a thermostat. John, what are the food grade chemicals you could suggest please. Not by trade name as they may not be available in Australia. Thanks Guys Link to comment Share on other sites More sharing options...
John McKee Posted October 25, 2012 Share Posted October 25, 2012 My guess is that you're sitting on an acidic wash, so a food grade lye should do you just fine as a base. If you're basic, then I would suggest a food grade phosphoric for an acid. I'm not sure that there are any negative effects of either suggestion aboce to a post fermentation wash, but if anyone has information please go ahead and share. However, I think you should be good to go with either chemical depending on your situation. Cheers Link to comment Share on other sites More sharing options...
jon_l Posted October 29, 2012 Share Posted October 29, 2012 As an aside, you can do this experiment next time you're tired of waiting for the head on your beer to go down. Stick your finger in your nose then swish that around in the head of the beer. Snot is a good surfactant and it'll knock down the head right away. ... Don't use snot. Dude, rub your finger on the outside of your nose. The oils do the job. Link to comment Share on other sites More sharing options...
Swede Posted October 29, 2012 Share Posted October 29, 2012 Looks like no-one has any ideas for a foam dector, so I will take advice from both the above posts. I have a backup burner under my still that I don't use, I will put a smaller nozzle in it and switch to that as I approach foam temperature. Would be nice though for switch over to be automatic. Maybe just a thermostat. John, what are the food grade chemicals you could suggest please. Not by trade name as they may not be available in Australia. Thanks Guys I have had a few ideas, but I'm wondering if there would be an issue inside the boiler. The minute voltages that are used to measure resistance pose no risk of a spark occurring but I wonder if there are explosion rating concerns that may arise by incorporating such a sensor. Two probes mounted a certain distance apart (4-6") along the side of the boiler simply measuring resistance could work. What type of resistance did you note when you you used a multimeter? The other issue with this type of sensor would be the liquid film that would form along the inside of the still from condensate and splash up may give a false reading and put the still in reduced heat mode... Food for thought. I may be able to give this a test run on my prototyping control system that I use as a testbed and development platform in the near future if your interested. I don't know if and/or how well it would work, but I could try it out and see. If it works would you be looking at a standalone single output control that would go inline with the on/off control circuit to your diesel burner, you could then modulate the on/off in a 0-100% PWM fashion to reduce heat input during the foaming stage. As the foam settles, the burner would re-engage, and as it foams up, the burner would cut off. Link to comment Share on other sites More sharing options...
Denver Distiller Posted October 29, 2012 Share Posted October 29, 2012 Fellas, you don't have to reinvent the wheel here. There are commercially available probes for foam. They are used in larger breweries to cut steam in the event of a boil-over in a kettle. Link to comment Share on other sites More sharing options...
Swede Posted October 30, 2012 Share Posted October 30, 2012 Fellas, you don't have to reinvent the wheel here. There are commercially available probes for foam. They are used in larger breweries to cut steam in the event of a boil-over in a kettle. Your absolutely right, I didn't realize that there was such an array of sensors already on the market... http://www.charis.uk.com/SureSense_Range.htm Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now