Traditional Mount Washington Rockpile Crunch Recipe

Winter on top of Mount Washington means high winds, snow, and of course, lots of rime ice! Rime ice is a phenomenon that occurs when supercooled water droplets freeze on contact with any surface they come into contact with. When foggy conditions occur concurrently with high winds, rime ice can accumulate pretty quickly. Unlike glaze ice, which is clear and dense, rime ice is opaque, light, and fluffy. These qualities make it the perfect ingredient for ice cream!

Rime ice cream (also known as Rockpile Crunch or R’ice cream) is a Mount Washington Observatory tradition that dates back before many generations of weather observers. Eric Pinder, a former observer, wrote about the unique dessert in his book Life at the Top first published in 1997. Life at the Top, “describes the joys and terrors of living in the clouds and explains Mount Washington’s geology and weather”. Also included in the book is a, “one-of-a-kind cookbook made up of recipes contributed by the Observatory staff”. If you are interested in seeing more MWOBS recipes and reading stories about observer life on Mount Washington, Pinder’s book is available at the MWOBS online shop or on Pinder’s website. All proceeds from the purchase of this book are donated to the observatory to support research and educational outreach.

Ira Seskin, a long-time summit volunteer, contributed this particular recipe for the book. I had the pleasure of working with Ira during his most recent shift volunteering where he told me all about the development of the recipe. According to Ira, the recipe was derived from the classic maple syrup snow, but using sweetened condensed milk gives a more creamy texture. When it comes to mix-ins, Ira says, “there are no rules, I would just use whatever they had up here (on the summit)”. He says for the base, “you can use rime ice or fresh snow,” then jokingly, “just don’t use yellow snow”. Although it has been many years since Ira came up with his recipe for rime ice cream, he still enjoys making it. His preferred mix-ins to use currently are strawberries and blueberries.

I happened upon the recipe for Rime Ice cream when planning for a Winter Storms EduTrip in December of 2022 and thought that it would make the perfect activity to include in the curriculum. After teaching participants about the many different types of ice and their formation processes, we went outside and collected rime ice. We then quickly went inside to gather ingredients and began the process of making the rime ice cream. To make traditional Rockpile Crunch, ingredients include rime ice or snow, sweetened condensed milk, chocolate chips, M&M’s Reese’s Pieces, chopped nuts, and raisins.

The EduTrip participants were so excited to watch the process unfold while I stirred and fellow weather Observer Hayden Pearson slowly poured in the sweetened condensed milk. It took quite some time and a lot of stirring, but eventually the EduTrip participants’ suspicions about the possibility of such a dessert were refuted. Everyone really enjoyed the sweet treat, one even commenting, “It tastes like a New England winter day”. See below for the full recipe as it appears in Life at the Top.

Rime Ice Cream (Contributed by Ira Seskin)

“This wintertime camping favorite, also known as “Rockpile Crunch,” tastes best with a fresh crop of Mount Washington rime ice. If none is available, plain snow will do just fine. (Caution: In the good old days, all fresh snow was white and clean. Unfortunately, pollutants and acidity in the atmosphere now make it unwise to eat snow in many areas. If that’s the case where you live, save this recipe for better days, when the air is clean again.)
2 quarts rime ice
14-oz can sweetened condensed milk
Chocoloate chips
M&M candies
Reese’s Pieces
Chopped Nuts

Place a 2-quart mixing bowl outdoors prior to a predicted snowfall (or fill it with existing rime ice). Carefully fold in the condensed milk until the mixture is slightly granular. If the milk is added too quickly, mix with a fork to correct the consistency. Fold in all remaining ingredients until it looks and tastes right. The mixture should be soft and creamy−like soft ice cream. Use ice pellets for an extra crunchy texture” (Life at the Top, Eric Pinder).

Alexandra Branton, Weather Observer & Education Specialist

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