Can't access custom claim - asp.net-mvc-5

Question

I am adding custom claim to the User.Identity for a web site using MVC5 and OWIN authentication. But I'm using local account sign in.
AuthenticationManager.SignOut(DefaultAuthenticationTypes.ExternalCookie);
ClaimsIdentity identity = await UserManager.CreateIdentityAsync(user, DefaultAuthenticationTypes.ExternalCookie);
identity.AddClaim(new Claim("TenantID", user.TenantID.ToString()));
AuthenticationManager.SignIn(new AuthenticationProperties()
{
IsPersistent = isPersistent
}, identity);
return await SignInOrTwoFactor(user, isPersistent);
But when I try to retrieve back, my custom claim does not exist in the collection. This is from IdentityExtension class :
public static short TenantID(this IIdentity identity)
{
if (identity == null) throw new ArgumentNullException("identity");
var ci = identity as ClaimsIdentity;
var value = ci != null ? ci.FindFirstValue(GlobalVariables.TenantIdIdentifier) : "0";
return short.Parse(value);
}
This is my startup code:
public void ConfigureAuth(IAppBuilder app)
{
// Configure the db context, user manager and role manager to use a single instance per request
app.CreatePerOwinContext(ApplicationDbContext.Create);
app.CreatePerOwinContext<ApplicationUserManager>(ApplicationUserManager.Create);
app.CreatePerOwinContext<ApplicationRoleManager>(ApplicationRoleManager.Create);
// Enable the application to use a cookie to store information for the signed in user
app.UseCookieAuthentication(new CookieAuthenticationOptions
{
AuthenticationType = DefaultAuthenticationTypes.ApplicationCookie,
LoginPath = new PathString("/Account/Login")
}); }

Answer 1

It works this way :
AuthenticationManager.SignOut(DefaultAuthenticationTypes.ExternalCookie);
ClaimsIdentity identity = await UserManager.CreateIdentityAsync(user, DefaultAuthenticationTypes.ExternalCookie);
await UserManager.AddClaimAsync(user.Id, new Claim(GlobalVariables.TenantIdIdentifier, user.TenantID.ToString()));
AuthenticationManager.SignIn(new AuthenticationProperties()
{
IsPersistent = isPersistent
}, identity);
return await SignInOrTwoFactor(user, isPersistent);