Grails - Unable to record Betamax tape

I have a simple test that I'm trying to write to test the YouTube Data Api (http://ift.tt/1Du0uDo). The test is using Betamax to intercept the request to the service.

I'm getting an error recording the HTTP exchange, however. The error is as follows:

INFO: Recording to 'search youtube success'
Apr 1, 2015 9:37:08 AM java_util_logging_Logger$log call
SEVERE: error recording HTTP exchange
java.io.UnsupportedEncodingException: UTF-8; type=feed
    at sun.nio.cs.StreamDecoder.forInputStreamReader(StreamDecoder.java:52)
    at java.io.InputStreamReader.<init>(InputStreamReader.java:83)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
    at org.codehaus.groovy.reflection.CachedConstructor.invoke(CachedConstructor.java:77)
    at org.codehaus.groovy.runtime.callsite.ConstructorSite$ConstructorSiteNoUnwrapNoCoerce.callConstructor(ConstructorSite.java:102)
    at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCallConstructor(CallSiteArray.java:57)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callConstructor(AbstractCallSite.java:182)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callConstructor(AbstractCallSite.java:194)
    at co.freeside.betamax.message.http.HttpResponseAdapter.getBodyAsText(HttpResponseAdapter.groovy:52)
    at co.freeside.betamax.message.Message$getBodyAsText.call(Unknown Source)
    at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:45)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:108)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:112)
    at co.freeside.betamax.message.filtering.HeaderFilteringResponse.getBodyAsText(HeaderFilteringResponse.groovy)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:90)
    at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:233)
    at groovy.lang.MetaClassImpl.getProperty(MetaClassImpl.java:1606)
    at groovy.lang.ExpandoMetaClass.getProperty(ExpandoMetaClass.java:1136)
    at groovy.lang.MetaClassImpl.getProperty(MetaClassImpl.java:3343)
    at groovy.lang.ExpandoMetaClass.getProperty(ExpandoMetaClass.java:1148)
    at co.freeside.betamax.message.filtering.HeaderFilteringMessage.getProperty(HeaderFilteringMessage.groovy)
    at org.codehaus.groovy.runtime.callsite.PogoGetPropertySite.getProperty(PogoGetPropertySite.java:47)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callGetProperty(AbstractCallSite.java:227)
    at co.freeside.betamax.tape.MemoryTape.recordResponse(MemoryTape.groovy:128)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:90)
    at org.codehaus.groovy.runtime.callsite.StaticMetaMethodSite$StaticMetaMethodSiteNoUnwrapNoCoerce.invoke(StaticMetaMethodSite.java:148)
    at org.codehaus.groovy.runtime.callsite.StaticMetaMethodSite.callStatic(StaticMetaMethodSite.java:99)
    at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCallStatic(CallSiteArray.java:53)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callStatic(AbstractCallSite.java:157)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callStatic(AbstractCallSite.java:165)
    at co.freeside.betamax.tape.MemoryTape.record(MemoryTape.groovy:82)
    at co.freeside.betamax.tape.yaml.YamlTape.super$2$record(YamlTape.groovy)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:90)
    at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:233)
    at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1082)
    at groovy.lang.ExpandoMetaClass.invokeMethod(ExpandoMetaClass.java:1106)
    at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.invokeMethodOnSuperN(ScriptBytecodeAdapter.java:128)
    at co.freeside.betamax.tape.yaml.YamlTape.record(YamlTape.groovy:57)
    at co.freeside.betamax.tape.Tape$record.call(Unknown Source)
    at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:45)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:108)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:120)
    at co.freeside.betamax.proxy.handler.TapeWriter.handle(TapeWriter.groovy:30)
    at co.freeside.betamax.proxy.handler.HttpHandler$handle.call(Unknown Source)
    at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:45)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:108)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:116)
    at co.freeside.betamax.proxy.handler.ChainedHttpHandler.chain(ChainedHttpHandler.groovy:14)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.codehaus.groovy.runtime.callsite.PogoMetaMethodSite$PogoCachedMethodSiteNoUnwrapNoCoerce.invoke(PogoMetaMethodSite.java:272)
    at org.codehaus.groovy.runtime.callsite.PogoMetaMethodSite.callCurrent(PogoMetaMethodSite.java:52)
    at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCallCurrent(CallSiteArray.java:49)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callCurrent(AbstractCallSite.java:133)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callCurrent(AbstractCallSite.java:141)
    at co.freeside.betamax.proxy.handler.TapeReader.handle(TapeReader.groovy:33)
    at co.freeside.betamax.proxy.handler.HttpHandler$handle.call(Unknown Source)
    at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:45)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:108)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:116)
    at co.freeside.betamax.proxy.jetty.BetamaxProxy.handle(BetamaxProxy.groovy:27)
    at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:116)
    at org.eclipse.jetty.server.handler.ConnectHandler.handle(ConnectHandler.java:196)
    at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:116)
    at org.eclipse.jetty.server.Server.handle(Server.java:346)
    at org.eclipse.jetty.server.HttpConnection.handleRequest(HttpConnection.java:581)
    at org.eclipse.jetty.server.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:1040)
    at org.eclipse.jetty.http.HttpParser.parseNext(HttpParser.java:592)
    at org.eclipse.jetty.http.HttpParser.parseAvailable(HttpParser.java:214)
    at org.eclipse.jetty.server.HttpConnection.handle(HttpConnection.java:411)
    at org.eclipse.jetty.io.nio.SelectChannelEndPoint.handle(SelectChannelEndPoint.java:526)
    at org.eclipse.jetty.io.nio.SelectChannelEndPoint$1.run(SelectChannelEndPoint.java:41)
    at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:528)
    at java.lang.Thread.run(Thread.java:695) 

If I remove the @Betamax annotation from the test everything works as expected.

Any suggestions?