Dry Ice + Liquid Nitrogen at the Same Time for Ice Cream?

In the recent live ice cream video Grant talked about how dry ice sinks to the bottom of the stand mixer bowl, while liquid nitrogen floats on top of the ice cream base. Besides having to source both materials, is there any reason why you couldn't use both at the same time so you're freezing from both sides? I'm thinking this would speed up the freezing process. Has anyone already tried this?

Find more posts tagged with

Recipes Q's

Comments

FrankM_3301

LN is so much colder (thus faster) that using both is completely unnecessary. Plus, with LN, you don't need to off-gas the C02 that builds up when using dry ice. If you have access to LN, that should be your top choice.

Dat_Phan_279256

In that live video Grant actually said he thinks dry ice is faster because it sinks into the base and cools more directly and effectively vs floating above the liquid base like liquid nitrogen does, because of the leidenfrost effect creating a gas layer. I'm not convinced yet that using only liquid nitrogen is the best way for going fast. I'd really like to hear from someone with practical experience rather than going from just comparing the temperatures of dry ice and liquid nitrogen, as Grant suggested temperature does not directly translate into cooling power.

FrankM_3301

I honestly can't speak to the science. I have, however, used both (both not together) to make ice cream. I feel like the LN is quicker, but not by that much. It is certainly easier to use (no powdering in a blender step), and I tend not to like the C02 that results from using dry ice (though it blows off over time). Unfortunately, I don't have access to LN on a regular basis so, use dry ice more frequently. However, it is not cheap, so I make the additional compromise of mostly using a regular ice cream machine. Using both LN and dry ice would increase the expense further. I would be interested in what folks have to say about this as an intellectual exercise. Of course, there is no reason you couldn't use both, but personally, I can't justify a practical reason to do so.

tshewman

I would tend to agree with @FrankM with the exception that it depends on a couple of other things. One the churning speed. The slower you go, the longer it takes for Ln2 and it's close to the same a for dry ice. Speed up the churning and you're exposing the LN2 to more surface area of the custard/base and thus freezing it quicker (you also don't need to torch the bowl as frequently) Next the aging really cuts both down, but I found with LN2 it takes less than 5 min vs CO2 which still took much longer.

fisher23

Personally, I have done both. I prefer the LN2, especially if you want to eat the ice cream shortly after. Dry ice ice cream becomes slightly carbonated which may subside after a longer ripening, mine never stayed around long enough to find out. Really though both freeze the ice cream so fast that I am not sure what if any benefit you would get from using both. My other concern would be that you would actually freeze the dry ice into the ice cream and you don't want to eat the dry ice. It will sublimate once the ice cream is warmer than the dry ice itself but your wait time will increase.

Dat_Phan_279256

Yeah I didn't think it was practical or cost effective. Definitely would be over the top. I'm asking because the scientist in me wants to know.

Dat_Phan_279256

Thanks for pointing out the effect of different churning speeds.

Dat_Phan_279256

I personally don't mind the carbonation, but I can see why people would want to avoid it.

I hadn't thought of the liquid nitrogen keeping the dry ice frozen. I'm thinking it would be possible to avoid the danger of eat dry ice if the dry ice is consistently crushed fine enough and spread evenly. I'm guessing the dry ice would sublimate fast enough to not be a problem.

dancurren

I actually intentionally carbonate some of my bases for my ice cream business - Rootbeer, Lemonade and Raspberry Champagne for example. But buth are so efficent and yield such a smooth ice cream that this seems unnecessary... then again, people told me that when I bought a dewar and I am sure they will say the same when I buy a LN2 plant next year