Sciencemadness Discussion Board

"Food Grade" vs "Industrial Grade" Dry Ice

sbbspartan - 27-9-2012 at 12:25

I was going to make some ice cream using dry ice later. I heard that it is really good, creamy, and even carbonated from the CO2.

However, the only dry ice I have found so far is from a fishing/hunting store. It is sold for $1.50 per pound, but it is "industrial grade".

My question is, how much does this matter? Are there any serious contaminants that would hurt me, versus if I used "food grade" dry ice? It's not like I would have it every day, just as a demonstration or once in a while thing. Does it depend on where it comes from or how it was made? Should I start looking for a new supplier, if I want to make ice cream with it?

Thanks.

zed - 27-9-2012 at 13:09

I saw food-grade Dry Ice for sale in a "Lucky" supermarket in Novato, California...about 2 months ago. It was priced at $1.70 per pound.

No big fanfare, the unit was just sitting in a quiet spot near the front door.

kristofvagyok - 27-9-2012 at 13:09

A similar question, but with the same answer: Would you eat the food grade or the industrial grade NaOH? Both are same purity, almost no difference.

sbbspartan - 27-9-2012 at 13:49

So "food grade" and "industrial grade" dry ice are almost the exact same purity? Safe to eat? I think I will look around a bit as well to see if I can find any more suppliers. Thanks.

bfesser - 27-9-2012 at 14:15

In the past, when I've sublimated dry ice from the grocery store where I used to work, I was always left with a small pile of dust, dirt, and metal shavings. I assume this was industrial grade. Food grade probably doesn't contain so much non-volatile crap.

watson.fawkes - 27-9-2012 at 16:02

Quote: Originally posted by bfesser  
In the past, when I've sublimated dry ice from the grocery store where I used to work, I was always left with a small pile of dust, dirt, and metal shavings. I assume this was industrial grade. Food grade probably doesn't contain so much non-volatile crap.
Dust and dirt I could imagine from condensing an exhaust stream. But metal shavings? Just how is "industrial grade" dry ice made, anyway? Whatever I thought I might know it just doesn't fit these contaminants.

Dr.Bob - 27-9-2012 at 16:15

Quote: Originally posted by sbbspartan  
I was going to make some ice cream using dry ice later. I heard that it is really good, creamy, and even carbonated from the CO2.


You're in Minn. right? Can't you just put cream outside and let it freeze on its own? :-)

There are several types of dry ice, blocks, powder, chunks. I have found most we use to be pretty clean, but we go through a few 100 pounds a day, and it is in big rolling plastic coolers. The stuff at most grocery stores has been pretty clean, usually blocks, which would be fine. But check to see if there is a welding or industrial gas place nearby, many sell dry ice.

Otherwise you might want to buy some and let it sublime to see how clean it is.

zed - 9-10-2012 at 11:17

This might be better posted in Acquisition, but since this is a recent topic.......

There having been many complaints about difficulty obtaining dry-ice. In fact, some of our UK friends have trouble obtaining even regular H2O ice. I can't, unfortunately, help them.

But, I did discover easily accessible Dry-Ice in the Portland area. Last night, at the Fred Meyers supermarket at the NE28th and Weidler St. store. I discovered it near the self-checkout area.

As usual for a dry-ice unit, it was located in a low-profile, nearly invisible refrigeration unit, near a high traffic area. Blocks of dry-ice sell for a friendly price of $.99 cents per pound. The cashier supervising the automated check-out area, where the unit is located, holds the access key. Other store employees, might be unaware that the store even stocks the product.

[Edited on 9-10-2012 by zed]

[Edited on 9-10-2012 by zed]

Magpie - 9-10-2012 at 17:21

A few years ago I could only find dry ice at a specialty distributor. Now it seems like every grocery store has it. Check Albertson's and Walmart.