[8 - 8] couple of years ago I went to ice cream
[8 - 12] College of seriously it's thing so Penn
[12 - 13] State has offered an ice cream short
[13 - 15] course in the middle of winter in the
[15 - 16] middle of nowhere
[16 - 19] for about a hundred and twenty years and
[19 - 20] the whole thing is ten days it's
[20 - 22] dedicated to the science of commercial
[22 - 24] ice cream now most the time when we
[24 - 25] think about ice cream we immediately go
[25 - 27] to flavor chocolate vanilla cookies and
[27 - 29] cream actually once had an ice cream
[29 - 31] that was lobster flavored in Maine I
[31 - 34] love lobster that was challenging but
[34 - 36] what makes her brakes great ice cream
[36 - 39] isn't flavor at all it's texture how it
[39 - 41] feels in your mouth and that is all
[41 - 44] science ice cream is many things it's an
[44 - 46] emulsion or a mixture of two things that
[46 - 48] don't want to be together fat and water
[48 - 50] in this case it's also a foam it's
[50 - 52] packed with tiny air bubbles that are
[52 - 53] put in there during the churning process
[53 - 56] and it's a multi-phase system so it
[56 - 58] contains solid liquid and gas all at the
[58 - 61] same time it's also delicious okay so
[61 - 62] here's the deal if you want to make
[62 - 64] great ice cream you have to know how to
[64 - 66] control water now I'm not talking about
[66 - 69] superpowers or Captain Planet or
[69 - 71] all ice cream bases are mostly water
[71 - 74] ranging anywhere from 55 percent up to
[74 - 76] 80 percent and that water is incredibly
[76 - 78] important as it freezes during the
[78 - 80] churning process it thickens the mix and
[80 - 82] it turns the whole thing refreshing and
[82 - 84] delightful now the size of the ice
[84 - 86] crystals that are formed during churning
[86 - 87] has a huge impact on the texture of the
[87 - 90] ice cream smooth high-quality ice cream
[90 - 91] has ice crystals that are so small our
[91 - 94] tongues simply can't detect them there's
[94 - 95] a lot of different ways to control water
[95 - 97] in ice cream base let's start with sugar
[97 - 100] and we all know that sugar sweetness but
[100 - 101] actually has an even more important role
[101 - 103] in ice cream and that's to affect the
[103 - 105] freezing point of the mixture when
[105 - 107] dissolved in water sugar lowers the
[107 - 109] temperature at which water freezes as
[109 - 111] more and more water freezes during the
[111 - 112] churning process the remaining water has
[112 - 114] an even higher concentration of sugar
[114 - 116] further lowering the freezing point
[116 - 118] here's what happens if you have too
[118 - 120] little sugar in the mix its rock-hard
[120 - 122] right out of the freezer as ice cream is
[122 - 124] unscrew beable and it's not pleasant to
[124 - 125] eat on the other hand too much sugar
[126 - 127] gives you something that is soupy and
[127 - 129] wet right out of the freezer that's
[129 - 131] because not enough of the water has
[131 - 133] turned to ice okay next up let's talk
[133 - 135] about fat the fat in ice cream comes
[135 - 137] primarily from cream and milk and the
[137 - 140] way that fat controls water is mostly by
[140 - 142] replacing it cream is roughly 36 percent
[142 - 145] fat and 59 percent water whereas milk is
[145 - 147] about four percent fat in 88 percent
[147 - 149] water using a higher proportion of
[149 - 151] fattier cream to leaner milk means we
[151 - 153] have less water in the mix unless water
[153 - 155] means we have less chance of forming
[155 - 157] large noticeable ice crystals that also
[157 - 159] lubricates our tongue so we're less
[159 - 161] likely to notice large ice crystals in
[161 - 163] the first place but there's a limit to
[163 - 164] how much fat you can squeeze into an ice
[164 - 166] cream base so commercial ice cream goes
[166 - 169] from about 10% fat up to 16 percent fat
[169 - 171] that high end of the range we're talking
[171 - 173] about super premium ice creams something
[173 - 175] like haagen-dazs the most common
[175 - 176] formulation for commercial ice cream is
[176 - 179] 14% fat that's the sweet spot too much
[179 - 181] fat in the mix causes two potential
[181 - 183] problems the first is that during
[183 - 185] churning that butter fat can actually
[185 - 186] break out of invention and from tiny
[186 - 189] flecks of butter that might sound like a
[189 - 190] nice thing to have flecks of butter in
[190 - 191] your ice cream but it's pretty
[191 - 193] unpleasant so the second reason that too
[193 - 194] much fat is a problem it's actually
[194 - 196] really fascinating and ice cream with
[196 - 198] too much fat won't feel cold enough to
[198 - 200] be refreshing even if it's at the exact
[200 - 202] same temperature as base that doesn't
[202 - 204] have too much fat now the reason is is
[204 - 206] that water has a higher thermal capacity
[206 - 208] than fat does that means that given the
[208 - 210] same amount of material at the same
[210 - 212] temperature water can actually hold a
[212 - 214] lot more energy than fat does so in an
[214 - 216] ice cream base the water is able to pull
[216 - 218] more energy out of our mouths than fat
[218 - 220] can the next way to control water is to
[220 - 223] limit its mobility so adding starches or
[223 - 225] hydrocolloids like carrageenan or
[225 - 227] various gums actually traps water and
[227 - 229] increases the viscosity of their ice
[229 - 231] cream mix so the basis thicker has a
[231 - 232] higher viscosity
[232 - 234] there's less of a chance for water
[234 - 235] molecules to find one another to form
[235 - 238] large noticeable ice crystals once again
[238 - 241] it's all about balance adding too much
[241 - 242] of an ingredient that binds up water and
[243 - 245] increases viscosity can give us a gummy
[245 - 246] ice cream or something that eats like a
[246 - 249] pudding oh my god remember how good
[249 - 252] pudding pops were and I want one of
[252 - 254] those okay that's a lot of ice cream
[254 - 255] science I think it's time to go into the
[255 - 257] kitchen and see if all in action the
[257 - 259] fastest way that I know how to make ice
[259 - 260] cream is with the liquid nitrogen liquid
[260 - 262] nitrogen not only makes you look really
[262 - 265] cool which it does it also is really
[265 - 267] really cool you know like really cool
[267 - 269] like negative 320 degrees Fahrenheit
[269 - 272] cool we can harness that coldness to
[272 - 274] make ice cream really fast the faster we
[274 - 276] freeze it the smaller the ice crystals
[276 - 278] will be so here's how you do it I take a
[278 - 279] stand mixer and we put the ice cream
[279 - 281] base in the bottom of the bowl then we
[281 - 283] use the paddle attachment that we mix it
[283 - 284] on low speed while we gradually add
[284 - 287] liquid nitrogen made this way we can
[287 - 289] have ice cream in two minutes flat
[289 - 292] that's incredibly fast if you make ice
[292 - 293] cream this way you can pretty much
[293 - 295] ignore everything I just said and still
[295 - 297] make ice cream that is incredibly smooth
[297 - 299] and really really nice but let's be real
[299 - 301] this is the ice cream maker we all have
[301 - 304] at home and it takes about 30 minutes to
[304 - 306] turn an ice cream base that is really
[306 - 308] slow so the scoop shops that we love to
[308 - 310] go to they have batch freezers that get
[310 - 312] the job done in about six to eight
[312 - 314] minutes so we got a slow freezer which
[314 - 317] we do we need a bulletproof ice cream
[317 - 318] base that means milk and cream in a
[318 - 320] ratio that Nets us that 14 percent fat
[320 - 322] sweet spot I'm gonna blend the milk with
[323 - 324] a vanilla beat to extract tons of flavor
[324 - 326] we're gonna strain it out later anyway
[326 - 328] next up we're gonna add sugar and also
[328 - 330] corn syrup you can see the corn syrup is
[330 - 331] feel really thick that's actually gonna
[331 - 333] increase the viscosity of the mix which
[333 - 335] we know is a good thing it's also less
[335 - 337] sweet than sugar which is great a lot of
[337 - 338] homemade ice cream can tend to be too
[338 - 340] sweet next we're gonna increase the
[340 - 342] viscosity bit more by adding some corn
[342 - 343] starch we're also going to add some
[343 - 346] nonfat dry milk powder it'll increase
[346 - 348] the viscosity a bit but more importantly
[348 - 350] it basically displaces water so we have
[350 - 352] less water in the mix less chance of
[352 - 354] making really big ice crystals okay so
[354 - 356] I'm gonna heat this up that cornstarch
[356 - 358] is gonna gel you can see we have a lot
[358 - 360] more viscosity that's a great thing now
[360 - 362] we just chill this base in the fridge
[362 - 364] until it's at fridge temp which is about
[364 - 366] 40 degrees then turn it in our ice cream
[366 - 367] maker we want to make sure that that
[367 - 369] canister was frozen for the least 24
[369 - 371] hours before we do this so it has of
[371 - 372] chilling power I'll let that go until
[372 - 375] it's 21 degrees Fahrenheit so it's nice
[375 - 377] and cold it's gonna look like soft-serve
[377 - 378] ice cream then we transfer it to another
[378 - 380] container that goes into the freezer
[380 - 382] until it is hard you should takes about
[382 - 384] four hours but overnight is great so all
[384 - 386] that's left to do now is scoop some into
[386 - 388] this bowl top it with peanut butter cups
[388 - 391] which I really like and this is how to
[391 - 395] eat ice cream
[398 - 398] did you like that episode you wish you
[398 - 399] went to ice cream College we'll hit that
[399 - 401] subscribe button and we'll see you next