As malt was one of the foods to pair for this month’s TGRWT I decided to do something with beer. I first considered making a beer gel since the Alinea book has a nice recipe (with potassium citrate and kappa carrageenan – I included the recipe in the hydrocolloid recipe collection), but since I didn’t have carrageenan at hand I decided to try a sorbet. A quick search gave me 4 recipes (links in the table below) and in order to compare these I decided to calculate sugar/beer and sugar/liquid ratios as these are quite crucial in order to obtain the desired consistency of a sorbet. The results are shown in the table below.

reference	beer mL	water mL	sugar g	sugar/liquid	sugar/beer
Recipe 1	330	257	340	0.58	1.03
Recipe 2	1360	50	383	0.27	0.28
Recipe 3	310	567*	311*	0.35	1.00
Recipe 4	710	370	335	0.31	0.47

* Recipe 3 uses milk instead of water. There are also 2 oz liquid glucose which I’ve not included since there is no information about the concentration.

I was surprised to find such a great difference between the recipes with regards to sugar and alcohol content. The large ranges for sugar/liquid and sugar/beer ratios (0.27-0.58 and 0.28-1.03 respectively) suggest to me that the recipes are a little arbitrary. Unfortunately I wasn’t able to find tables plotting out the the combined effect of sucrose and alcohol on sorbets – perhaps you know about such a resource? (I tried googling for ethanol, sucrose and freezing point depression without success) In the end I figured recipe 4 seemed most reasonable and scaled it down a little. I had planned on using lemon juice, but there were no lemons left in the fridge so I went with balsamic vinegar instead.

Beer sorbet
150 mL water
140 g sugar
0,85 g gelatin (1/2 sheet, 0,14%)
10 mL balsamic vinegar
300 mL beer (pilsner type, 4.5% alcohol)

Bring water and sugar to boil and stir until sugar has dissolved. Remove from heat, add bloomed gelatin. Add beer and vinegar. Cool and freeze. If freezing without an ice cream maker, mix well once frozen and freeze again. I served it with diced galia melon, marinated in soy sauce and sugar.

Scientific considerations: I intentionally did not boil the beer to avoid oxidation and an sulfurous flavor, and it’s probably also advisable to let the sugar/gelatin mixture cool down before adding the beer. I’m not particularily fond of stale beer, and not heating the beer is a way to avoid this. To reduce syneresis and inhibit formation of large crystals I added a little gelatin to the recipe (locust bean gum or agar/xanthan will also do the trick). The consistency was perhaps a bit too soft, but the following numbers should be a useful guide when adjusting the recipe.

Final sugar concentration: 23%
Final alcohol concentration: 2.25% (vol%)
Final gelatin concentration: 0.14%

Creamy texture after second freezing!

Verdict: The beer sorbet was a pleasant surprise! Very creamy texture, perhaps a little on the soft side, but the gelatin helped maintain structure. The flavor was sweet, savory and acidic at the same time. The melon with soy sauce however was not so great. The leftover beer sorbet will be served with lemon and lime marinated melon in stead of the soy sauce

As shown in the figure, the radical reacts with sulfur containing proteins, thereby forming a thiol called 3-methylbut-2-ene-1-thiol or just MBT for short. The amazing thing about this compound is that we can smell it at concentrations as low as a few parts per billion (ppb). The perhaps not-so-amazing thing is that this compound gives beer a “skunky” aroma. Obviously one would want to avoid this, and that’s why beer is sold in dark brown glass bottles that act as the beer’s own sunglasses. Canned beer of course will not go skunky (well not until it’s poured into a glass and served outside in bright sunlight – that will turn any beer skunky within minutes).

Unfortunately however, not all beer is sold in dark bottles! One well known brand is shown in the picture below…

And yes – as you might have figured out, 3-methylbut-2-ene-1-thiol is present in Corona beer (and other brands sold in clear bottles, to a lesser extent MBT is also found in green bottled beer). For some references to “skunky” off flavours in beer check out these links: here, here and here. The ubiquitious slice of lime served with Corona beer is nothing but clever marketing since it helps camouflage the smelly thiol formed! (but how well does lime actually camouflage the thiol aroma?)

The take home message is: keep your olive oil, milk, butter and beer away from sunlight!